Example #1
0
def DenseNet121(input_shape=None):
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=True)

    img_input = layers.Input(shape=input_shape)

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    x = layers.ZeroPadding2D(padding=((3, 3), (3, 3)))(img_input)
    x = layers.Conv2D(64, 7, strides=2, use_bias=False, name='conv1/conv')(x)
    x = layers.BatchNormalization(axis=bn_axis,
                                  epsilon=1.001e-5,
                                  name='conv1/bn')(x)
    x = layers.Activation('relu', name='conv1/relu')(x)
    x = layers.ZeroPadding2D(padding=((1, 1), (1, 1)))(x)
    x = layers.MaxPooling2D(3, strides=2, name='pool1')(x)

    x = dense_block(x, 6, name='conv2')
    x = transition_block(x, 0.5, name='pool2')
    x = dense_block(x, 12, name='conv3')
    x = transition_block(x, 0.5, name='pool3')
    x = dense_block(x, 24, name='conv4')
    x = transition_block(x, 0.5, name='pool4')
    x = dense_block(x, 16, name='conv5')

    x = layers.BatchNormalization(axis=bn_axis, epsilon=1.001e-5, name='bn')(x)
    x = layers.Activation('relu', name='relu')(x)

    x = layers.GlobalAveragePooling2D(name='avg_pool')(x)

    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    # Create model.
    model = training.Model(img_input, x, name='densenet121')

    return model
Example #2
0
def ResNet50V2(input_shape=None):
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=True)

    img_input = layers.Input(shape=input_shape)

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    x = layers.ZeroPadding2D(padding=((3, 3), (3, 3)),
                             name='conv1_pad')(img_input)
    x = layers.Conv2D(64, 7, strides=2, use_bias=True, name='conv1_conv')(x)

    x = layers.ZeroPadding2D(padding=((1, 1), (1, 1)), name='pool1_pad')(x)
    x = layers.MaxPooling2D(3, strides=2, name='pool1_pool')(x)

    x = stack2(x, 64, 3, name='conv2')
    x = stack2(x, 128, 4, name='conv3')
    x = stack2(x, 256, 6, name='conv4')
    x = stack2(x, 512, 3, stride1=1, name='conv5')

    x = layers.BatchNormalization(axis=bn_axis,
                                  epsilon=1.001e-5,
                                  name='post_bn')(x)
    x = layers.Activation('relu', name='post_relu')(x)

    x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    # Create model.
    model = training.Model(img_input, x, name="resnet50v2")

    return model
Example #3
0
def InceptionV3(
    include_top=True,
    weights='imagenet',
    input_tensor=None,
    input_shape=None,
    pooling=None,
    classes=1000,
    classifier_activation='softmax',
):
    """Instantiates the Inception v3 architecture.

  Reference paper:
  - [Rethinking the Inception Architecture for Computer Vision](
      http://arxiv.org/abs/1512.00567) (CVPR 2016)

  Optionally loads weights pre-trained on ImageNet.
  Note that the data format convention used by the model is
  the one specified in the `tf.keras.backend.image_data_format()`.

  Caution: Be sure to properly pre-process your inputs to the application.
  Please see `applications.inception_v3.preprocess_input` for an example.

  Arguments:
    include_top: Boolean, whether to include the fully-connected
      layer at the top, as the last layer of the network. Default to `True`.
    weights: One of `None` (random initialization),
      `imagenet` (pre-training on ImageNet),
      or the path to the weights file to be loaded. Default to `imagenet`.
    input_tensor: Optional Keras tensor (i.e. output of `layers.Input()`)
      to use as image input for the model. `input_tensor` is useful for sharing
      inputs between multiple different networks. Default to None.
    input_shape: Optional shape tuple, only to be specified
      if `include_top` is False (otherwise the input shape
      has to be `(299, 299, 3)` (with `channels_last` data format)
      or `(3, 299, 299)` (with `channels_first` data format).
      It should have exactly 3 inputs channels,
      and width and height should be no smaller than 75.
      E.g. `(150, 150, 3)` would be one valid value.
      `input_shape` will be ignored if the `input_tensor` is provided.
    pooling: Optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` (default) means that the output of the model will be
          the 4D tensor output of the last convolutional block.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a 2D tensor.
      - `max` means that global max pooling will be applied.
    classes: optional number of classes to classify images
      into, only to be specified if `include_top` is True, and
      if no `weights` argument is specified. Default to 1000.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    if not (weights in {'imagenet', None} or os.path.exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=299,
        min_size=75,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if backend.image_data_format() == 'channels_first':
        channel_axis = 1
    else:
        channel_axis = 3

    x = conv2d_bn(img_input, 32, 3, 3, strides=(2, 2), padding='valid')
    x = conv2d_bn(x, 32, 3, 3, padding='valid')
    x = conv2d_bn(x, 64, 3, 3)
    x = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv2d_bn(x, 80, 1, 1, padding='valid')
    x = conv2d_bn(x, 192, 3, 3, padding='valid')
    x = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)

    # mixed 0: 35 x 35 x 256
    branch1x1 = conv2d_bn(x, 64, 1, 1)

    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 32, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed0')

    # mixed 1: 35 x 35 x 288
    branch1x1 = conv2d_bn(x, 64, 1, 1)

    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed1')

    # mixed 2: 35 x 35 x 288
    branch1x1 = conv2d_bn(x, 64, 1, 1)

    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed2')

    # mixed 3: 17 x 17 x 768
    branch3x3 = conv2d_bn(x, 384, 3, 3, strides=(2, 2), padding='valid')

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl,
                             96,
                             3,
                             3,
                             strides=(2, 2),
                             padding='valid')

    branch_pool = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)
    x = layers.concatenate([branch3x3, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed3')

    # mixed 4: 17 x 17 x 768
    branch1x1 = conv2d_bn(x, 192, 1, 1)

    branch7x7 = conv2d_bn(x, 128, 1, 1)
    branch7x7 = conv2d_bn(branch7x7, 128, 1, 7)
    branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)

    branch7x7dbl = conv2d_bn(x, 128, 1, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 1, 7)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
    x = layers.concatenate([branch1x1, branch7x7, branch7x7dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed4')

    # mixed 5, 6: 17 x 17 x 768
    for i in range(2):
        branch1x1 = conv2d_bn(x, 192, 1, 1)

        branch7x7 = conv2d_bn(x, 160, 1, 1)
        branch7x7 = conv2d_bn(branch7x7, 160, 1, 7)
        branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)

        branch7x7dbl = conv2d_bn(x, 160, 1, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 7, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 1, 7)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 7, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)

        branch_pool = layers.AveragePooling2D((3, 3),
                                              strides=(1, 1),
                                              padding='same')(x)
        branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
        x = layers.concatenate(
            [branch1x1, branch7x7, branch7x7dbl, branch_pool],
            axis=channel_axis,
            name='mixed' + str(5 + i))

    # mixed 7: 17 x 17 x 768
    branch1x1 = conv2d_bn(x, 192, 1, 1)

    branch7x7 = conv2d_bn(x, 192, 1, 1)
    branch7x7 = conv2d_bn(branch7x7, 192, 1, 7)
    branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)

    branch7x7dbl = conv2d_bn(x, 192, 1, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
    x = layers.concatenate([branch1x1, branch7x7, branch7x7dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed7')

    # mixed 8: 8 x 8 x 1280
    branch3x3 = conv2d_bn(x, 192, 1, 1)
    branch3x3 = conv2d_bn(branch3x3,
                          320,
                          3,
                          3,
                          strides=(2, 2),
                          padding='valid')

    branch7x7x3 = conv2d_bn(x, 192, 1, 1)
    branch7x7x3 = conv2d_bn(branch7x7x3, 192, 1, 7)
    branch7x7x3 = conv2d_bn(branch7x7x3, 192, 7, 1)
    branch7x7x3 = conv2d_bn(branch7x7x3,
                            192,
                            3,
                            3,
                            strides=(2, 2),
                            padding='valid')

    branch_pool = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)
    x = layers.concatenate([branch3x3, branch7x7x3, branch_pool],
                           axis=channel_axis,
                           name='mixed8')

    # mixed 9: 8 x 8 x 2048
    for i in range(2):
        branch1x1 = conv2d_bn(x, 320, 1, 1)

        branch3x3 = conv2d_bn(x, 384, 1, 1)
        branch3x3_1 = conv2d_bn(branch3x3, 384, 1, 3)
        branch3x3_2 = conv2d_bn(branch3x3, 384, 3, 1)
        branch3x3 = layers.concatenate([branch3x3_1, branch3x3_2],
                                       axis=channel_axis,
                                       name='mixed9_' + str(i))

        branch3x3dbl = conv2d_bn(x, 448, 1, 1)
        branch3x3dbl = conv2d_bn(branch3x3dbl, 384, 3, 3)
        branch3x3dbl_1 = conv2d_bn(branch3x3dbl, 384, 1, 3)
        branch3x3dbl_2 = conv2d_bn(branch3x3dbl, 384, 3, 1)
        branch3x3dbl = layers.concatenate([branch3x3dbl_1, branch3x3dbl_2],
                                          axis=channel_axis)

        branch_pool = layers.AveragePooling2D((3, 3),
                                              strides=(1, 1),
                                              padding='same')(x)
        branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
        x = layers.concatenate(
            [branch1x1, branch3x3, branch3x3dbl, branch_pool],
            axis=channel_axis,
            name='mixed' + str(9 + i))
    if include_top:
        # Classification block
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input
    # Create model.
    model = training.Model(inputs, x, name='inception_v3')

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            weights_path = data_utils.get_file(
                'inception_v3_weights_tf_dim_ordering_tf_kernels.h5',
                WEIGHTS_PATH,
                cache_subdir='models',
                file_hash='9a0d58056eeedaa3f26cb7ebd46da564')
        else:
            weights_path = data_utils.get_file(
                'inception_v3_weights_tf_dim_ordering_tf_kernels_notop.h5',
                WEIGHTS_PATH_NO_TOP,
                cache_subdir='models',
                file_hash='bcbd6486424b2319ff4ef7d526e38f63')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #4
0
    def assemble_layers(self):
        from tensorflow.python.keras import backend, layers
        from tensorflow.python.keras.applications import imagenet_utils

        include_top = True
        weights = None
        pooling = None
        classes = 1
        if nnstate.FLAGS.PRED_SIZE != 2:
            err('bad')
        classifier_activation = 'sigmoid'

        x = conv2d_bn(self.inputs, 32, 3, strides=2, padding='valid')
        x = conv2d_bn(x, 32, 3, padding='valid')
        x = conv2d_bn(x, 64, 3)
        x = layers.MaxPooling2D(3, strides=2)(x)
        x = conv2d_bn(x, 80, 1, padding='valid')
        x = conv2d_bn(x, 192, 3, padding='valid')
        x = layers.MaxPooling2D(3, strides=2)(x)

        # Mixed 5b (Inception-A block): 35 x 35 x 320
        branch_0 = conv2d_bn(x, 96, 1)
        branch_1 = conv2d_bn(x, 48, 1)
        branch_1 = conv2d_bn(branch_1, 64, 5)
        branch_2 = conv2d_bn(x, 64, 1)
        branch_2 = conv2d_bn(branch_2, 96, 3)
        branch_2 = conv2d_bn(branch_2, 96, 3)
        branch_pool = layers.AveragePooling2D(3, strides=1, padding='same')(x)
        branch_pool = conv2d_bn(branch_pool, 64, 1)
        branches = [branch_0, branch_1, branch_2, branch_pool]
        channel_axis = 1 if backend.image_data_format(
        ) == 'channels_first' else 3
        x = layers.Concatenate(axis=channel_axis, name='mixed_5b')(branches)

        # 10x block35 (Inception-ResNet-A block): 35 x 35 x 320
        for block_idx in range(1, 11):
            x = inception_resnet_block(x,
                                       scale=0.17,
                                       block_type='block35',
                                       block_idx=block_idx)

        # Mixed 6a (Reduction-A block): 17 x 17 x 1088
        branch_0 = conv2d_bn(x, 384, 3, strides=2, padding='valid')
        branch_1 = conv2d_bn(x, 256, 1)
        branch_1 = conv2d_bn(branch_1, 256, 3)
        branch_1 = conv2d_bn(branch_1, 384, 3, strides=2, padding='valid')
        branch_pool = layers.MaxPooling2D(3, strides=2, padding='valid')(x)
        branches = [branch_0, branch_1, branch_pool]
        x = layers.Concatenate(axis=channel_axis, name='mixed_6a')(branches)

        # 20x block17 (Inception-ResNet-B block): 17 x 17 x 1088
        for block_idx in range(1, 21):
            x = inception_resnet_block(x,
                                       scale=0.1,
                                       block_type='block17',
                                       block_idx=block_idx)

        # Mixed 7a (Reduction-B block): 8 x 8 x 2080
        branch_0 = conv2d_bn(x, 256, 1)
        branch_0 = conv2d_bn(branch_0, 384, 3, strides=2, padding='valid')
        branch_1 = conv2d_bn(x, 256, 1)
        branch_1 = conv2d_bn(branch_1, 288, 3, strides=2, padding='valid')
        branch_2 = conv2d_bn(x, 256, 1)
        branch_2 = conv2d_bn(branch_2, 288, 3)
        branch_2 = conv2d_bn(branch_2, 320, 3, strides=2, padding='valid')
        branch_pool = layers.MaxPooling2D(3, strides=2, padding='valid')(x)
        branches = [branch_0, branch_1, branch_2, branch_pool]
        x = layers.Concatenate(axis=channel_axis, name='mixed_7a')(branches)

        # 10x block8 (Inception-ResNet-C block): 8 x 8 x 2080
        for block_idx in range(1, 10):
            x = inception_resnet_block(x,
                                       scale=0.2,
                                       block_type='block8',
                                       block_idx=block_idx)
        x = inception_resnet_block(x,
                                   scale=1.,
                                   activation=None,
                                   block_type='block8',
                                   block_idx=10)

        # Final convolution block: 8 x 8 x 1536
        x = conv2d_bn(x, 1536, 1, name='conv_7b')

        if include_top:
            # Classification block
            x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
            imagenet_utils.validate_activation(classifier_activation, weights)
            x = layers.Dense(classes,
                             activation=classifier_activation,
                             name='predictions')(x)
        else:
            if pooling == 'avg':
                x = layers.GlobalAveragePooling2D()(x)
            elif pooling == 'max':
                x = layers.GlobalMaxPooling2D()(x)

        return x
Example #5
0
def ResNet(stack_fn,
           preact,
           use_bias,
           model_name='resnet',
           include_top=True,
           weights='imagenet',
           input_tensor=None,
           input_shape=None,
           pooling=None,
           classes=1000,
           classifier_activation='softmax',
           **kwargs):
    """Instantiates the ResNet, ResNetV2, and ResNeXt architecture.
  Optionally loads weights pre-trained on ImageNet.
  Note that the data format convention used by the model is
  the one specified in your Keras config at `~/.keras/keras.json`.
  Caution: Be sure to properly pre-process your inputs to the application.
  Please see `applications.resnet.preprocess_input` for an example.
  Arguments:
    stack_fn: a function that returns output tensor for the
      stacked residual blocks.
    preact: whether to use pre-activation or not
      (True for ResNetV2, False for ResNet and ResNeXt).
    use_bias: whether to use biases for convolutional layers or not
      (True for ResNet and ResNetV2, False for ResNeXt).
    model_name: string, model name.
    include_top: whether to include the fully-connected
      layer at the top of the network.
    weights: one of `None` (random initialization),
      'imagenet' (pre-training on ImageNet),
      or the path to the weights file to be loaded.
    input_tensor: optional Keras tensor
      (i.e. output of `layers.Input()`)
      to use as image input for the model.
    input_shape: optional shape tuple, only to be specified
      if `include_top` is False (otherwise the input shape
      has to be `(224, 224, 3)` (with `channels_last` data format)
      or `(3, 224, 224)` (with `channels_first` data format).
      It should have exactly 3 inputs channels.
    pooling: optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` means that the output of the model will be
          the 4D tensor output of the
          last convolutional layer.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional layer, and thus
          the output of the model will be a 2D tensor.
      - `max` means that global max pooling will
          be applied.
    classes: optional number of classes to classify images
      into, only to be specified if `include_top` is True, and
      if no `weights` argument is specified.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.
    **kwargs: For backwards compatibility only.
  Returns:
    A `keras.Model` instance.
  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    if 'layers' in kwargs:
        global layers
        layers = kwargs.pop('layers')
    if kwargs:
        raise ValueError('Unknown argument(s): %s' % (kwargs, ))
    if not (weights in {'imagenet', None} or os.path.exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    x = layers.ZeroPadding2D(padding=((3, 3), (3, 3)),
                             name='conv1_pad')(img_input)
    x = layers.Conv2D(64, 7, strides=2, use_bias=use_bias,
                      name='conv1_conv')(x)

    if not preact:
        x = tf.keras.layers.experimental.SyncBatchNormalization(
            axis=bn_axis, name='conv1_bn')(x)
        x = layers.Activation('relu', name='conv1_relu')(x)

    x = layers.ZeroPadding2D(padding=((1, 1), (1, 1)), name='pool1_pad')(x)
    x = layers.MaxPooling2D(3, strides=2, name='pool1_pool')(x)

    x = stack_fn(x)

    if preact:
        x = tf.keras.layers.experimental.SyncBatchNormalization(
            axis=bn_axis, name='post_bn')(x)
        x = layers.Activation('relu', name='post_relu')(x)

    if include_top:
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D(name='max_pool')(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs, x, name=model_name)

    # Load weights.
    if (weights == 'imagenet') and (model_name in WEIGHTS_HASHES):
        if include_top:
            file_name = model_name + '_weights_tf_dim_ordering_tf_kernels.h5'
            file_hash = WEIGHTS_HASHES[model_name][0]
        else:
            file_name = model_name + '_weights_tf_dim_ordering_tf_kernels_notop.h5'
            file_hash = WEIGHTS_HASHES[model_name][1]
        weights_path = data_utils.get_file(file_name,
                                           BASE_WEIGHTS_PATH + file_name,
                                           cache_subdir='models',
                                           file_hash=file_hash)
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #6
0
def VGG19(include_top=True,
          weights='imagenet',
          input_tensor=None,
          input_shape=None,
          pooling=None,
          classes=1000,
          classifier_activation='softmax'):
    """Instantiates the VGG19 architecture.

  Reference:
  - [Very Deep Convolutional Networks for Large-Scale Image Recognition](
      https://arxiv.org/abs/1409.1556) (ICLR 2015)

  By default, it loads weights pre-trained on ImageNet. Check 'weights' for
  other options.

  This model can be built both with 'channels_first' data format
  (channels, height, width) or 'channels_last' data format
  (height, width, channels).

  The default input size for this model is 224x224.

  Caution: Be sure to properly pre-process your inputs to the application.
  Please see `applications.vgg19.preprocess_input` for an example.

  Arguments:
    include_top: whether to include the 3 fully-connected
      layers at the top of the network.
    weights: one of `None` (random initialization),
        'imagenet' (pre-training on ImageNet),
        or the path to the weights file to be loaded.
    input_tensor: optional Keras tensor
      (i.e. output of `layers.Input()`)
      to use as image input for the model.
    input_shape: optional shape tuple, only to be specified
      if `include_top` is False (otherwise the input shape
      has to be `(224, 224, 3)`
      (with `channels_last` data format)
      or `(3, 224, 224)` (with `channels_first` data format).
      It should have exactly 3 inputs channels,
      and width and height should be no smaller than 32.
      E.g. `(200, 200, 3)` would be one valid value.
    pooling: Optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` means that the output of the model will be
          the 4D tensor output of the
          last convolutional block.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a 2D tensor.
      - `max` means that global max pooling will
          be applied.
    classes: optional number of classes to classify images
      into, only to be specified if `include_top` is True, and
      if no `weights` argument is specified.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    if not (weights in {'imagenet', None} or file_io.file_exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')
    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor
    # Block 1
    x = layers.Conv2D(64, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block1_conv1')(img_input)
    x = layers.Conv2D(64, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block1_conv2')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = layers.Conv2D(128, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block2_conv1')(x)
    x = layers.Conv2D(128, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block2_conv2')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv1')(x)
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv2')(x)
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv3')(x)
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv4')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv1')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv2')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv3')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv4')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv1')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv2')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv3')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv4')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    if include_top:
        # Classification block
        x = layers.Flatten(name='flatten')(x)
        x = layers.Dense(4096, activation='relu', name='fc1')(x)
        x = layers.Dense(4096, activation='relu', name='fc2')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input
    # Create model.
    model = training.Model(inputs, x, name='vgg19')

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            weights_path = data_utils.get_file(
                'vgg19_weights_tf_dim_ordering_tf_kernels.h5',
                WEIGHTS_PATH,
                cache_subdir='models',
                file_hash='cbe5617147190e668d6c5d5026f83318')
        else:
            weights_path = data_utils.get_file(
                'vgg19_weights_tf_dim_ordering_tf_kernels_notop.h5',
                WEIGHTS_PATH_NO_TOP,
                cache_subdir='models',
                file_hash='253f8cb515780f3b799900260a226db6')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #7
0
def MobileNet(input_shape=None,
              alpha=1.0,
              depth_multiplier=1,
              dropout=1e-3,
              include_top=True,
              weights='imagenet',
              input_tensor=None,
              pooling=None,
              classes=1000,
              classifier_activation='softmax',
              **kwargs):
    global layers
    if 'layers' in kwargs:
        layers = kwargs.pop('layers')
    else:
        layers = VersionAwareLayers()
    if kwargs:
        raise ValueError('Unknown argument(s): %s' % (kwargs, ))
    if not (weights in {'imagenet', None} or file_io.file_exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top` '
            'as true, `classes` should be 1000')

    # Determine proper input shape and default size.
    if input_shape is None:
        default_size = 224
    else:
        if backend.image_data_format() == 'channels_first':
            rows = input_shape[1]
            cols = input_shape[2]
        else:
            rows = input_shape[0]
            cols = input_shape[1]

        if rows == cols and rows in [128, 160, 192, 224]:
            default_size = rows
        else:
            default_size = 224

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if backend.image_data_format() == 'channels_last':
        row_axis, col_axis = (0, 1)
    else:
        row_axis, col_axis = (1, 2)
    rows = input_shape[row_axis]
    cols = input_shape[col_axis]

    if weights == 'imagenet':
        if depth_multiplier != 1:
            raise ValueError('If imagenet weights are being loaded, '
                             'depth multiplier must be 1')

        if alpha not in [0.25, 0.50, 0.75, 1.0]:
            raise ValueError('If imagenet weights are being loaded, '
                             'alpha can be one of'
                             '`0.25`, `0.50`, `0.75` or `1.0` only.')

        if rows != cols or rows not in [128, 160, 192, 224]:
            rows = 224
            logging.warning('`input_shape` is undefined or non-square, '
                            'or `rows` is not in [128, 160, 192, 224]. '
                            'Weights for input shape (224, 224) will be'
                            ' loaded as the default.')

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    x = _conv_block(img_input, 32, strides=(2, 2), block_id=0)

    x = _conv_block(x, 64, block_id=1)

    x = _conv_block(x, 128, strides=(2, 2), block_id=2)

    x = _conv_block(x, 128, block_id=3)

    x = _conv_block(x, 256, strides=(2, 2), block_id=4)

    x = _conv_block(x, 256, block_id=5)

    x = _conv_block(x, 512, strides=(2, 2), block_id=6)
    x = _conv_block(x, 512, block_id=7)
    x = _conv_block(x, 512, block_id=8)
    x = _conv_block(x, 512, block_id=9)
    x = _conv_block(x, 512, block_id=10)

    x = _conv_block(x, 512, block_id=11)

    x = _conv_block(x, 1024, strides=(2, 2), block_id=12)

    x = _conv_block(x, 1024, block_id=13)

    if include_top:
        if backend.image_data_format() == 'channels_first':
            shape = (int(1024 * alpha), 1, 1)
        else:
            shape = (1, 1, int(1024 * alpha))

        x = layers.GlobalAveragePooling2D()(x)
        x = layers.Reshape(shape, name='reshape_1')(x)
        x = layers.Dropout(dropout, name='dropout')(x)
        x = layers.Conv2D(classes, (1, 1), padding='same',
                          name='conv_preds')(x)
        x = layers.Reshape((classes, ), name='reshape_2')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Activation(activation=classifier_activation,
                              name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs,
                           x,
                           name='mobilenet_%0.2f_%s' % (alpha, rows))

    # Load weights.
    if weights == 'imagenet':
        if alpha == 1.0:
            alpha_text = '1_0'
        elif alpha == 0.75:
            alpha_text = '7_5'
        elif alpha == 0.50:
            alpha_text = '5_0'
        else:
            alpha_text = '2_5'

        if include_top:
            model_name = 'mobilenet_%s_%d_tf.h5' % (alpha_text, rows)
            weight_path = BASE_WEIGHT_PATH + model_name
            weights_path = data_utils.get_file(model_name,
                                               weight_path,
                                               cache_subdir='models')
        else:
            model_name = 'mobilenet_%s_%d_tf_no_top.h5' % (alpha_text, rows)
            weight_path = BASE_WEIGHT_PATH + model_name
            weights_path = data_utils.get_file(model_name,
                                               weight_path,
                                               cache_subdir='models')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
def EfficientNet(width_coefficient,
                 depth_coefficient,
                 default_size,
                 dropout_rate=0.2,
                 drop_connect_rate=0.2,
                 depth_divisor=8,
                 activation='swish',
                 blocks_args='default',
                 model_name='efficientnet',
                 include_top=True,
                 weights='imagenet',
                 input_tensor=None,
                 input_shape=None,
                 pooling=None,
                 classes=1000,
                 classifier_activation='softmax'):
    """Instantiates the EfficientNet architecture using given scaling coefficients.

  Args:
    width_coefficient: float, scaling coefficient for network width.
    depth_coefficient: float, scaling coefficient for network depth.
    default_size: integer, default input image size.
    dropout_rate: float, dropout rate before final classifier layer.
    drop_connect_rate: float, dropout rate at skip connections.
    depth_divisor: integer, a unit of network width.
    activation: activation function.
    blocks_args: list of dicts, parameters to construct block modules.
    model_name: string, model name.
    include_top: whether to include the fully-connected
        layer at the top of the network.
    weights: one of `None` (random initialization),
          'imagenet' (pre-training on ImageNet),
          or the path to the weights file to be loaded.
    input_tensor: optional Keras tensor
        (i.e. output of `layers.Input()`)
        to use as image input for the model.
    input_shape: optional shape tuple, only to be specified
        if `include_top` is False.
        It should have exactly 3 inputs channels.
    pooling: optional pooling mode for feature extraction
        when `include_top` is `False`.
        - `None` means that the output of the model will be
            the 4D tensor output of the
            last convolutional layer.
        - `avg` means that global average pooling
            will be applied to the output of the
            last convolutional layer, and thus
            the output of the model will be a 2D tensor.
        - `max` means that global max pooling will
            be applied.
    classes: optional number of classes to classify images
        into, only to be specified if `include_top` is True, and
        if no `weights` argument is specified.
    classifier_activation: A `str` or callable. The activation function to use
        on the "top" layer. Ignored unless `include_top=True`. Set
        `classifier_activation=None` to return the logits of the "top" layer.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    if blocks_args == 'default':
        blocks_args = DEFAULT_BLOCKS_ARGS

    if not (weights in {'imagenet', None} or file_io.file_exists_v2(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    def round_filters(filters, divisor=depth_divisor):
        """Round number of filters based on depth multiplier."""
        filters *= width_coefficient
        new_filters = max(divisor,
                          int(filters + divisor / 2) // divisor * divisor)
        # Make sure that round down does not go down by more than 10%.
        if new_filters < 0.9 * filters:
            new_filters += divisor
        return int(new_filters)

    def round_repeats(repeats):
        """Round number of repeats based on depth multiplier."""
        return int(math.ceil(depth_coefficient * repeats))

    # Build stem
    x = img_input
    x = layers.Rescaling(1. / 255.)(x)
    x = layers.Normalization(axis=bn_axis)(x)

    x = layers.ZeroPadding2D(padding=imagenet_utils.correct_pad(x, 3),
                             name='stem_conv_pad')(x)
    x = layers.Conv2D(round_filters(32),
                      3,
                      strides=2,
                      padding='valid',
                      use_bias=False,
                      kernel_initializer=CONV_KERNEL_INITIALIZER,
                      name='stem_conv')(x)
    x = layers.BatchNormalization(axis=bn_axis, name='stem_bn')(x)
    x = layers.Activation(activation, name='stem_activation')(x)

    # Build blocks
    blocks_args = copy.deepcopy(blocks_args)

    b = 0
    blocks = float(sum(round_repeats(args['repeats']) for args in blocks_args))
    for (i, args) in enumerate(blocks_args):
        assert args['repeats'] > 0
        # Update block input and output filters based on depth multiplier.
        args['filters_in'] = round_filters(args['filters_in'])
        args['filters_out'] = round_filters(args['filters_out'])

        for j in range(round_repeats(args.pop('repeats'))):
            # The first block needs to take care of stride and filter size increase.
            if j > 0:
                args['strides'] = 1
                args['filters_in'] = args['filters_out']
            x = block(x,
                      activation,
                      drop_connect_rate * b / blocks,
                      name='block{}{}_'.format(i + 1, chr(j + 97)),
                      **args)
            b += 1

    # Build top
    x = layers.Conv2D(round_filters(1280),
                      1,
                      padding='same',
                      use_bias=False,
                      kernel_initializer=CONV_KERNEL_INITIALIZER,
                      name='top_conv')(x)
    x = layers.BatchNormalization(axis=bn_axis, name='top_bn')(x)
    x = layers.Activation(activation, name='top_activation')(x)
    if include_top:
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        if dropout_rate > 0:
            x = layers.Dropout(dropout_rate, name='top_dropout')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         kernel_initializer=DENSE_KERNEL_INITIALIZER,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D(name='max_pool')(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs, x, name=model_name)

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            file_suffix = '.h5'
            file_hash = WEIGHTS_HASHES[model_name[-2:]][0]
        else:
            file_suffix = '_notop.h5'
            file_hash = WEIGHTS_HASHES[model_name[-2:]][1]
        file_name = model_name + file_suffix
        weights_path = data_utils.get_file(file_name,
                                           BASE_WEIGHTS_PATH + file_name,
                                           cache_subdir='models',
                                           file_hash=file_hash)
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)
    return model
def MobileNetV2XNNPACK(input_shape=None,
                       alpha=1.0,
                       include_top=True,
                       weights='imagenet',
                       input_tensor=None,
                       pooling=None,
                       classes=1000,
                       classifier_activation='softmax',
                       **kwargs):
    """Instantiates the MobileNetV2 architecture.

  Reference:
  - [MobileNetV2: Inverted Residuals and Linear Bottlenecks](
      https://arxiv.org/abs/1801.04381) (CVPR 2018)

  Optionally loads weights pre-trained on ImageNet.

  Caution: Be sure to properly pre-process your inputs to the application.
  Please see `applications.mobilenet_v2.preprocess_input` for an example.

  Arguments:
    input_shape: Optional shape tuple, to be specified if you would
      like to use a model with an input image resolution that is not
      (224, 224, 3).
      It should have exactly 3 inputs channels (224, 224, 3).
      You can also omit this option if you would like
      to infer input_shape from an input_tensor.
      If you choose to include both input_tensor and input_shape then
      input_shape will be used if they match, if the shapes
      do not match then we will throw an error.
      E.g. `(160, 160, 3)` would be one valid value.
    alpha: Float between 0 and 1. controls the width of the network.
      This is known as the width multiplier in the MobileNetV2 paper,
      but the name is kept for consistency with `applications.MobileNetV1`
      model in Keras.
      - If `alpha` < 1.0, proportionally decreases the number
          of filters in each layer.
      - If `alpha` > 1.0, proportionally increases the number
          of filters in each layer.
      - If `alpha` = 1, default number of filters from the paper
          are used at each layer.
    include_top: Boolean, whether to include the fully-connected
      layer at the top of the network. Defaults to `True`.
    weights: String, one of `None` (random initialization),
      'imagenet' (pre-training on ImageNet),
      or the path to the weights file to be loaded.
    input_tensor: Optional Keras tensor (i.e. output of
      `layers.Input()`)
      to use as image input for the model.
    pooling: String, optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` means that the output of the model
          will be the 4D tensor output of the
          last convolutional block.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a
          2D tensor.
      - `max` means that global max pooling will
          be applied.
    classes: Integer, optional number of classes to classify images
      into, only to be specified if `include_top` is True, and
      if no `weights` argument is specified.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.
    **kwargs: For backwards compatibility only.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape or invalid alpha, rows when
      weights='imagenet'
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    global layers
    if 'layers' in kwargs:
        layers = kwargs.pop('layers')
    else:
        layers = VersionAwareLayers()
    if kwargs:
        raise ValueError('Unknown argument(s): %s' % (kwargs, ))
    if not (weights in {'imagenet', None} or os.path.exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top` '
            'as true, `classes` should be 1000')

    # Determine proper input shape and default size.
    # If both input_shape and input_tensor are used, they should match
    if input_shape is not None and input_tensor is not None:
        try:
            is_input_t_tensor = backend.is_keras_tensor(input_tensor)
        except ValueError:
            try:
                is_input_t_tensor = backend.is_keras_tensor(
                    layer_utils.get_source_inputs(input_tensor))
            except ValueError:
                raise ValueError('input_tensor: ', input_tensor,
                                 'is not type input_tensor')
        if is_input_t_tensor:
            if backend.image_data_format == 'channels_first':
                if backend.int_shape(input_tensor)[1] != input_shape[1]:
                    raise ValueError(
                        'input_shape: ', input_shape, 'and input_tensor: ',
                        input_tensor,
                        'do not meet the same shape requirements')
            else:
                if backend.int_shape(input_tensor)[2] != input_shape[1]:
                    raise ValueError(
                        'input_shape: ', input_shape, 'and input_tensor: ',
                        input_tensor,
                        'do not meet the same shape requirements')
        else:
            raise ValueError('input_tensor specified: ', input_tensor,
                             'is not a keras tensor')

    # If input_shape is None, infer shape from input_tensor
    if input_shape is None and input_tensor is not None:

        try:
            backend.is_keras_tensor(input_tensor)
        except ValueError:
            raise ValueError('input_tensor: ', input_tensor, 'is type: ',
                             type(input_tensor), 'which is not a valid type')

        if input_shape is None and not backend.is_keras_tensor(input_tensor):
            default_size = 224
        elif input_shape is None and backend.is_keras_tensor(input_tensor):
            if backend.image_data_format() == 'channels_first':
                rows = backend.int_shape(input_tensor)[2]
                cols = backend.int_shape(input_tensor)[3]
            else:
                rows = backend.int_shape(input_tensor)[1]
                cols = backend.int_shape(input_tensor)[2]

            if rows == cols and rows in [96, 128, 160, 192, 224]:
                default_size = rows
            else:
                default_size = 224

    # If input_shape is None and no input_tensor
    elif input_shape is None:
        default_size = 224

    # If input_shape is not None, assume default size
    else:
        if backend.image_data_format() == 'channels_first':
            rows = input_shape[1]
            cols = input_shape[2]
        else:
            rows = input_shape[0]
            cols = input_shape[1]

        if rows == cols and rows in [96, 128, 160, 192, 224]:
            default_size = rows
        else:
            default_size = 224

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if backend.image_data_format() == 'channels_last':
        row_axis, col_axis = (0, 1)
    else:
        row_axis, col_axis = (1, 2)
    rows = input_shape[row_axis]
    cols = input_shape[col_axis]

    if weights == 'imagenet':
        if alpha not in [0.35, 0.50, 0.75, 1.0, 1.3, 1.4]:
            raise ValueError('If imagenet weights are being loaded, '
                             'alpha can be one of `0.35`, `0.50`, `0.75`, '
                             '`1.0`, `1.3` or `1.4` only.')

        if rows != cols or rows not in [96, 128, 160, 192, 224]:
            rows = 224
            logging.warning('`input_shape` is undefined or non-square, '
                            'or `rows` is not in [96, 128, 160, 192, 224].'
                            ' Weights for input shape (224, 224) will be'
                            ' loaded as the default.')

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    channel_axis = 1 if backend.image_data_format() == 'channels_first' else -1

    first_block_filters = _make_divisible(32 * alpha, 8)
    # x = layers.ZeroPadding2D(
    #     padding=imagenet_utils.correct_pad(img_input, 3),
    #     name='Conv1_pad')(img_input)
    x = img_input
    x = layers.Conv2D(first_block_filters,
                      kernel_size=3,
                      strides=(2, 2),
                      padding='same',
                      use_bias=False,
                      name='Conv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  epsilon=1e-3,
                                  momentum=0.999,
                                  name='bn_Conv1')(x)
    x = layers.ReLU(6., name='Conv1_relu')(x)

    x = _inverted_res_block(x,
                            filters=16,
                            alpha=alpha,
                            stride=1,
                            expansion=1,
                            block_id=0)

    x = _inverted_res_block(x,
                            filters=24,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=1)
    x = _inverted_res_block(x,
                            filters=24,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=2)

    x = _inverted_res_block(x,
                            filters=32,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=3)
    x = _inverted_res_block(x,
                            filters=32,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=4)
    x = _inverted_res_block(x,
                            filters=32,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=5)

    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=6)
    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=7)
    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=8)
    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=9)

    x = _inverted_res_block(x,
                            filters=96,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=10)
    x = _inverted_res_block(x,
                            filters=96,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=11)
    x = _inverted_res_block(x,
                            filters=96,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=12)

    x = _inverted_res_block(x,
                            filters=160,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=13)
    x = _inverted_res_block(x,
                            filters=160,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=14)
    x = _inverted_res_block(x,
                            filters=160,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=15)

    x = _inverted_res_block(x,
                            filters=320,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=16)

    # no alpha applied to last conv as stated in the paper:
    # if the width multiplier is greater than 1 we
    # increase the number of output channels
    if alpha > 1.0:
        last_block_filters = _make_divisible(1280 * alpha, 8)
    else:
        last_block_filters = 1280

    x = layers.Conv2D(last_block_filters,
                      kernel_size=1,
                      use_bias=False,
                      name='Conv_1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  epsilon=1e-3,
                                  momentum=0.999,
                                  name='Conv_1_bn')(x)
    x = layers.ReLU(6., name='out_relu')(x)

    if include_top:
        # Use XNNPACK compatible average pooling
        # x = layers.GlobalAveragePooling2D()(x)
        x = layers.AveragePooling2D(pool_size=(7, 7))(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        # x = layers.Dense(classes, activation=classifier_activation,
        #                  name='predictions')(x)
        # Implement the top dense layer as a convolution, so that we don't need to remove spatial dims
        x = layers.Conv2D(classes, kernel_size=1, name='predictions')(x)
        x = layers.Softmax()(x)

    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs,
                           x,
                           name='mobilenetv2_%0.2f_%s' % (alpha, rows))

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            model_name = ('mobilenet_v2_weights_tf_dim_ordering_tf_kernels_' +
                          str(alpha) + '_' + str(rows) + '.h5')
            weight_path = BASE_WEIGHT_PATH + model_name
            weights_path = data_utils.get_file(model_name,
                                               weight_path,
                                               cache_subdir='models')
        else:
            model_name = ('mobilenet_v2_weights_tf_dim_ordering_tf_kernels_' +
                          str(alpha) + '_' + str(rows) + '_no_top' + '.h5')
            weight_path = BASE_WEIGHT_PATH + model_name
            weights_path = data_utils.get_file(model_name,
                                               weight_path,
                                               cache_subdir='models')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #10
0
def MobileNet(input_shape=None, alpha=1.0, depth_multiplier=1, dropout=1e-3):
    if input_shape is None:
        default_size = 224
    else:
        if backend.image_data_format() == 'channels_first':
            rows = input_shape[1]
            cols = input_shape[2]
        else:
            rows = input_shape[0]
            cols = input_shape[1]

        if rows == cols and rows in [128, 160, 192, 224]:
            default_size = rows
        else:
            default_size = 224

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=True)

    row_axis = 0 if backend.image_data_format() == 'channels_last' else 0

    rows = input_shape[row_axis]
    img_input = layers.Input(shape=input_shape)

    x = _conv_block(img_input, 32, alpha, strides=(2, 2))
    x = _depthwise_conv_block(x, 64, alpha, depth_multiplier, block_id=1)

    x = _depthwise_conv_block(
        x, 128, alpha, depth_multiplier, strides=(2, 2), block_id=2)
    x = _depthwise_conv_block(x, 128, alpha, depth_multiplier, block_id=3)

    x = _depthwise_conv_block(
        x, 256, alpha, depth_multiplier, strides=(2, 2), block_id=4)
    x = _depthwise_conv_block(x, 256, alpha, depth_multiplier, block_id=5)

    x = _depthwise_conv_block(
        x, 512, alpha, depth_multiplier, strides=(2, 2), block_id=6)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=7)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=8)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=9)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=10)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=11)

    x = _depthwise_conv_block(
        x, 1024, alpha, depth_multiplier, strides=(2, 2), block_id=12)
    x = _depthwise_conv_block(x, 1024, alpha, depth_multiplier, block_id=13)

    if backend.image_data_format() == 'channels_first':
        shape = (int(1024 * alpha), 1, 1)
    else:
        shape = (1, 1, int(1024 * alpha))

    x = layers.GlobalAveragePooling2D()(x)
    x = layers.Reshape(shape, name='reshape_1')(x)
    x = layers.Dropout(dropout, name='dropout')(x)
    x = layers.Conv2D(NUM_CLASSES, (1, 1), padding='same', name='conv_preds')(x)
    x = layers.Reshape((NUM_CLASSES,), name='reshape_2')(x)
    imagenet_utils.validate_activation('softmax', None)
    x = layers.Activation(activation='softmax',
                          name='predictions')(x)

    # Create model.
    model = training.Model(img_input, x, name='mobilenet_%0.2f_%s' % (alpha, rows))

    return model
Example #11
0
def ResNet(stack_fn,
           preact,
           use_bias,
           model_name='resnet',
           include_top=True,
           weights='imagenet',
           input_tensor=None,
           input_shape=None,
           pooling=None,
           classes=1000,
           classifier_activation='softmax',
           **kwargs):
    global layers
    if 'layers' in kwargs:
        layers = kwargs.pop('layers')
    else:
        layers = VersionAwareLayers()
    if kwargs:
        raise ValueError('Unknown argument(s): %s' % (kwargs, ))
    if not (weights in {'imagenet', None} or file_io.file_exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    # x = layers.ZeroPadding2D(
    #     padding=((3, 3), (3, 3)), name='conv1_pad')(img_input)
    x = layers.Conv2D(64,
                      3,
                      strides=1,
                      padding='SAME',
                      use_bias=use_bias,
                      kernel_initializer='glorot_normal',
                      name='conv1_conv')(img_input)

    if not preact:
        x = layers.BatchNormalization(axis=bn_axis,
                                      epsilon=2.001e-5,
                                      momentum=0.9,
                                      name='conv1_bn')(x)
        x = layers.PReLU(shared_axes=[1, 2],
                         alpha_initializer='glorot_normal',
                         name='conv1_prelu')(x)

    # x = layers.ZeroPadding2D(padding=((1, 1), (1, 1)), name='pool1_pad')(x)
    # x = layers.MaxPooling2D(3, strides=2, name='pool1_pool')(x)

    x = stack_fn(x)

    if preact:
        x = layers.BatchNormalization(axis=bn_axis,
                                      epsilon=2.001e-5,
                                      momentum=0.9,
                                      name='post_bn')(x)
        x = layers.PReLU(shared_axes=[1, 2],
                         alpha_initializer='glorot_normal',
                         name='post_prelu')(x)

    if include_top:
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D(name='max_pool')(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs, x, name=model_name)

    # Load weights.
    if (weights == 'imagenet') and (model_name in WEIGHTS_HASHES):
        if include_top:
            file_name = model_name + '_weights_tf_dim_ordering_tf_kernels.h5'
            file_hash = WEIGHTS_HASHES[model_name][0]
        else:
            file_name = model_name + '_weights_tf_dim_ordering_tf_kernels_notop.h5'
            file_hash = WEIGHTS_HASHES[model_name][1]
        weights_path = data_utils.get_file(file_name,
                                           BASE_WEIGHTS_PATH + file_name,
                                           cache_subdir='models',
                                           file_hash=file_hash)
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #12
0
def MobileNetV2(input_shape=None, alpha=1.0):
    if input_shape is None:
        default_size = 224
    else:
        if backend.image_data_format() == 'channels_first':
            rows = input_shape[1]
            cols = input_shape[2]
        else:
            rows = input_shape[0]
            cols = input_shape[1]

        if rows == cols and rows in [96, 128, 160, 192, 224]:
            default_size = rows
        else:
            default_size = 224

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=True)

    row_axis = 0 if backend.image_data_format() == 'channels_last' else 1

    rows = input_shape[row_axis]
    img_input = layers.Input(shape=input_shape)
    channel_axis = 1 if backend.image_data_format() == 'channels_first' else -1

    first_block_filters = _make_divisible(32 * alpha, 8)
    x = layers.ZeroPadding2D(padding=imagenet_utils.correct_pad(img_input, 3),
                             name='Conv1_pad')(img_input)
    x = layers.Conv2D(first_block_filters,
                      kernel_size=3,
                      strides=(2, 2),
                      padding='valid',
                      use_bias=False,
                      name='Conv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  epsilon=1e-3,
                                  momentum=0.999,
                                  name='bn_Conv1')(x)
    x = layers.ReLU(6., name='Conv1_relu')(x)

    x = _inverted_res_block(x,
                            filters=16,
                            alpha=alpha,
                            stride=1,
                            expansion=1,
                            block_id=0)

    x = _inverted_res_block(x,
                            filters=24,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=1)
    x = _inverted_res_block(x,
                            filters=24,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=2)

    x = _inverted_res_block(x,
                            filters=32,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=3)
    x = _inverted_res_block(x,
                            filters=32,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=4)
    x = _inverted_res_block(x,
                            filters=32,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=5)

    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=6)
    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=7)
    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=8)
    x = _inverted_res_block(x,
                            filters=64,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=9)

    x = _inverted_res_block(x,
                            filters=96,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=10)
    x = _inverted_res_block(x,
                            filters=96,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=11)
    x = _inverted_res_block(x,
                            filters=96,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=12)

    x = _inverted_res_block(x,
                            filters=160,
                            alpha=alpha,
                            stride=2,
                            expansion=6,
                            block_id=13)
    x = _inverted_res_block(x,
                            filters=160,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=14)
    x = _inverted_res_block(x,
                            filters=160,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=15)

    x = _inverted_res_block(x,
                            filters=320,
                            alpha=alpha,
                            stride=1,
                            expansion=6,
                            block_id=16)

    # no alpha applied to last conv as stated in the paper:
    # if the width multiplier is greater than 1 we
    # increase the number of output channels
    if alpha > 1.0:
        last_block_filters = _make_divisible(1280 * alpha, 8)
    else:
        last_block_filters = 1280

    x = layers.Conv2D(last_block_filters,
                      kernel_size=1,
                      use_bias=False,
                      name='Conv_1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  epsilon=1e-3,
                                  momentum=0.999,
                                  name='Conv_1_bn')(x)
    x = layers.ReLU(6., name='out_relu')(x)

    x = layers.GlobalAveragePooling2D()(x)
    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    # Create model.
    model = training.Model(img_input,
                           x,
                           name='mobilenetv2_%0.2f_%s' % (alpha, rows))

    return model
def efficientnetB0(width_coeff=1,
                   depth_coeff=1,
                   default_img_size=224,
                   dropoutrate=0.2,
                   drop_connect_rate=0.2,
                   depth_divisor=8,
                   activations='swish',
                   block_args='default',
                   include_top=True,
                   weights='imagenet',
                   input_tensor=None,
                   input_shape=None,
                   pooling=None,
                   classes=1000,
                   classifier_activation='softmax'):

    if block_args == 'default':
        block_args = DEFAULT_BLOCKS_ARGS

    if not (weights in {'imagenet', None} or file_io.file_exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # proper input shape check

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_img_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    def round_filters(filters, divisor=depth_divisor):
        """ round number of filters based on depth multiplier"""
        filters *= width_coeff
        new_filters = max(divisor,
                          int(filters + divisor / 2) // divisor * divisor)
        #making sure round down does not go down by 10%
        if new_filters < 0.9 * filters:
            new_filters += divisor
        return int(new_filters)

    def round_repeats(repeats):
        """Round number of repeats based on depth multiplier."""
        return int(math.ceil(depth_coeff * repeats))

    #building stem

    x = img_input
    x = layers.Rescaling(1. / 255.)(x)
    x = layers.Normalization(axis=bn_axis)(x)

    x = layers.ZeroPadding2D(padding=imagenet_utils.correct_pad(x, 3))(x)
    x = layers.Conv2D(round_filters(32),
                      kernel_size=3,
                      strides=2,
                      padding='valid',
                      use_bias=False,
                      kernel_initializer=CONV_KERNEL_INITIALIZER)(x)

    x = layers.BatchNormalization(axis=bn_axis)(x)
    x = layers.Activation(activations)(x)

    #building blocks
    block_args = copy.deepcopy(block_args)

    b = 0
    blocks = float(sum(round_repeats(args['repeats']) for args in block_args))

    for (i, args) in enumerate(block_args):
        assert args['repeats'] > 0

        args['filters_in'] = round_filters(args['filters_in'])
        args['filters_out'] = round_filters(args['filters_out'])

        for j in range(round_repeats(args.pop('repeats'))):
            # The first block needs to take care of stride and filter size increase.
            if j > 0:
                args['strides'] = 1
                args['filters_in'] = args['filters_out']

            x = mbconvblock(inputs=x,
                            activations=activations,
                            droprate=drop_connect_rate * b / blocks,
                            name=str(i),
                            **args)
            b += 1

    #build top

    x = layers.Conv2D(round_filters(1280),
                      kernel_size=1,
                      padding='same',
                      use_bias=False,
                      kernel_initializer=CONV_KERNEL_INITIALIZER)(x)

    x = layers.BatchNormalization(axis=bn_axis)(x)
    x = layers.Activation(activations)(x)

    if include_top:
        x = layers.GlobalAveragePooling2D()(x)
        if dropoutrate > 0:
            x = layers.Dropout(dropoutrate)(x)
        imagenet_utils.validate_activation(classifier_activation, weights)

        x = layers.Dense(classes,
                         activation=classifier_activation,
                         kernel_initializer=DENSE_KERNEL_INITIALIZER)(x)

    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    #creating model
    model = training.Model(inputs, x)

    return model
Example #14
0
def InceptionV3(input_shape=None):
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=299,
        min_size=75,
        data_format=backend.image_data_format(),
        require_flatten=True)

    img_input = layers.Input(shape=input_shape)

    if backend.image_data_format() == 'channels_first':
        channel_axis = 1
    else:
        channel_axis = 3

    x = conv2d_bn(img_input, 32, 3, 3, strides=(2, 2), padding='valid')
    x = conv2d_bn(x, 32, 3, 3, padding='valid')
    x = conv2d_bn(x, 64, 3, 3)
    x = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv2d_bn(x, 80, 1, 1, padding='valid')
    x = conv2d_bn(x, 192, 3, 3, padding='valid')
    x = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)

    # mixed 0: 35 x 35 x 256
    branch1x1 = conv2d_bn(x, 64, 1, 1)

    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 32, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed0')

    # mixed 1: 35 x 35 x 288
    branch1x1 = conv2d_bn(x, 64, 1, 1)

    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed1')

    # mixed 2: 35 x 35 x 288
    branch1x1 = conv2d_bn(x, 64, 1, 1)

    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed2')

    # mixed 3: 17 x 17 x 768
    branch3x3 = conv2d_bn(x, 384, 3, 3, strides=(2, 2), padding='valid')

    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl,
                             96,
                             3,
                             3,
                             strides=(2, 2),
                             padding='valid')

    branch_pool = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)
    x = layers.concatenate([branch3x3, branch3x3dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed3')

    # mixed 4: 17 x 17 x 768
    branch1x1 = conv2d_bn(x, 192, 1, 1)

    branch7x7 = conv2d_bn(x, 128, 1, 1)
    branch7x7 = conv2d_bn(branch7x7, 128, 1, 7)
    branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)

    branch7x7dbl = conv2d_bn(x, 128, 1, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 1, 7)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
    x = layers.concatenate([branch1x1, branch7x7, branch7x7dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed4')

    # mixed 5, 6: 17 x 17 x 768
    for i in range(2):
        branch1x1 = conv2d_bn(x, 192, 1, 1)

        branch7x7 = conv2d_bn(x, 160, 1, 1)
        branch7x7 = conv2d_bn(branch7x7, 160, 1, 7)
        branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)

        branch7x7dbl = conv2d_bn(x, 160, 1, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 7, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 1, 7)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 7, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)

        branch_pool = layers.AveragePooling2D((3, 3),
                                              strides=(1, 1),
                                              padding='same')(x)
        branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
        x = layers.concatenate(
            [branch1x1, branch7x7, branch7x7dbl, branch_pool],
            axis=channel_axis,
            name='mixed' + str(5 + i))

    # mixed 7: 17 x 17 x 768
    branch1x1 = conv2d_bn(x, 192, 1, 1)

    branch7x7 = conv2d_bn(x, 192, 1, 1)
    branch7x7 = conv2d_bn(branch7x7, 192, 1, 7)
    branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)

    branch7x7dbl = conv2d_bn(x, 192, 1, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)

    branch_pool = layers.AveragePooling2D((3, 3),
                                          strides=(1, 1),
                                          padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
    x = layers.concatenate([branch1x1, branch7x7, branch7x7dbl, branch_pool],
                           axis=channel_axis,
                           name='mixed7')

    # mixed 8: 8 x 8 x 1280
    branch3x3 = conv2d_bn(x, 192, 1, 1)
    branch3x3 = conv2d_bn(branch3x3,
                          320,
                          3,
                          3,
                          strides=(2, 2),
                          padding='valid')

    branch7x7x3 = conv2d_bn(x, 192, 1, 1)
    branch7x7x3 = conv2d_bn(branch7x7x3, 192, 1, 7)
    branch7x7x3 = conv2d_bn(branch7x7x3, 192, 7, 1)
    branch7x7x3 = conv2d_bn(branch7x7x3,
                            192,
                            3,
                            3,
                            strides=(2, 2),
                            padding='valid')

    branch_pool = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)
    x = layers.concatenate([branch3x3, branch7x7x3, branch_pool],
                           axis=channel_axis,
                           name='mixed8')

    # mixed 9: 8 x 8 x 2048
    for i in range(2):
        branch1x1 = conv2d_bn(x, 320, 1, 1)

        branch3x3 = conv2d_bn(x, 384, 1, 1)
        branch3x3_1 = conv2d_bn(branch3x3, 384, 1, 3)
        branch3x3_2 = conv2d_bn(branch3x3, 384, 3, 1)
        branch3x3 = layers.concatenate([branch3x3_1, branch3x3_2],
                                       axis=channel_axis,
                                       name='mixed9_' + str(i))

        branch3x3dbl = conv2d_bn(x, 448, 1, 1)
        branch3x3dbl = conv2d_bn(branch3x3dbl, 384, 3, 3)
        branch3x3dbl_1 = conv2d_bn(branch3x3dbl, 384, 1, 3)
        branch3x3dbl_2 = conv2d_bn(branch3x3dbl, 384, 3, 1)
        branch3x3dbl = layers.concatenate([branch3x3dbl_1, branch3x3dbl_2],
                                          axis=channel_axis)

        branch_pool = layers.AveragePooling2D((3, 3),
                                              strides=(1, 1),
                                              padding='same')(x)
        branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
        x = layers.concatenate(
            [branch1x1, branch3x3, branch3x3dbl, branch_pool],
            axis=channel_axis,
            name='mixed' + str(9 + i))
    # Classification block
    x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    # Create model.
    model = training.Model(img_input, x, name='inception_v3')

    return model
Example #15
0
def VGG16(input_shape=None):
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=True)

    img_input = layers.Input(shape=input_shape)

    # Block 1
    x = layers.Conv2D(64, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block1_conv1')(img_input)
    x = layers.Conv2D(64, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block1_conv2')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = layers.Conv2D(128, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block2_conv1')(x)
    x = layers.Conv2D(128, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block2_conv2')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv1')(x)
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv2')(x)
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv3')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv1')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv2')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv3')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv1')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv2')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv3')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    # Classification block
    x = layers.Flatten(name='flatten')(x)
    x = layers.Dense(4096, activation='relu', name='fc1')(x)
    x = layers.Dense(4096, activation='relu', name='fc2')(x)

    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    # Create model.
    model = training.Model(img_input, x, name='vgg16')

    return model
Example #16
0
def MobileNet(input_shape=None,
              alpha=1.0,
              depth_multiplier=1,
              dropout=1e-3,
              include_top=True,
              weights='imagenet',
              input_tensor=None,
              pooling=None,
              classes=1000,
              classifier_activation='softmax',
              **kwargs):

    global layers
    if 'layers' in kwargs:
        layers = kwargs.pop('layers')
    else:
        layers = VersionAwareLayers()
    if kwargs:
        raise ValueError('Unknown argument(s): %s' % (kwargs, ))
    if not (weights in {'imagenet', None} or file_io.file_exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top` '
            'as true, `classes` should be 1000')

    # Determine proper input shape and default size.
    if input_shape is None:
        default_size = 224
    else:
        if backend.image_data_format() == 'channels_first':
            rows = input_shape[1]
            cols = input_shape[2]
        else:
            rows = input_shape[0]
            cols = input_shape[1]

        if rows == cols and rows in [128, 160, 192, 224]:
            default_size = rows
        else:
            default_size = 224

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if backend.image_data_format() == 'channels_last':
        row_axis, col_axis = (0, 1)
    else:
        row_axis, col_axis = (1, 2)
    rows = input_shape[row_axis]
    cols = input_shape[col_axis]

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    x = _conv_block(img_input, 32, alpha, strides=(8, 8))

    #x = _depthwise_conv_block(
    #       x, 128, alpha, depth_multiplier, strides=(2,2), block_id=2)

    #x = _depthwise_conv_block(
    #       x, 1024, alpha, depth_multiplier, strides=(2,2))

    x = _depthwise_conv_block(x, 1024, alpha, depth_multiplier, block_id=13)

    if include_top:
        if backend.image_data_format() == 'channels_first':
            shape = (int(1024 * alpha), 1, 1)
        else:
            shape = (1, 1, int(1024 * alpha))

        x = layers.GlobalAveragePooling2D()(x)
        x = layers.Reshape(shape, name='reshape_1')(x)
        x = layers.Conv2D(classes, (1, 1), padding='same',
                          name='conv_preds')(x)
        x = layers.Reshape((classes, ), name='reshape_2')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Activation(activation=classifier_activation,
                              name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs,
                           x,
                           name='mobilenet_%0.2f_%s' % (alpha, rows))

    return model
Example #17
0
def MobileNet(input_shape=None,
              alpha=1.0,
              depth_multiplier=1,
              dropout=1e-3,
              include_top=True,
              weights='imagenet',
              input_tensor=None,
              pooling=None,
              classes=1000,
              classifier_activation='softmax',
              **kwargs):
    """Instantiates the MobileNet architecture.
  Reference:
  - [MobileNets: Efficient Convolutional Neural Networks
     for Mobile Vision Applications](
      https://arxiv.org/abs/1704.04861)
  Optionally loads weights pre-trained on ImageNet.
  Note that the data format convention used by the model is
  the one specified in the `tf.keras.backend.image_data_format()`.
  Note: each Keras Application expects a specific kind of input preprocessing.
  For MobileNet, call `tf.keras.applications.mobilenet.preprocess_input`
  on your inputs before passing them to the model.
  Arguments:
    input_shape: Optional shape tuple, only to be specified if `include_top`
      is False (otherwise the input shape has to be `(224, 224, 3)` (with
      `channels_last` data format) or (3, 224, 224) (with `channels_first`
      data format). It should have exactly 3 inputs channels, and width and
      height should be no smaller than 32. E.g. `(200, 200, 3)` would be one
      valid value. Default to `None`.
      `input_shape` will be ignored if the `input_tensor` is provided.
    alpha: Controls the width of the network. This is known as the width
      multiplier in the MobileNet paper. - If `alpha` < 1.0, proportionally
      decreases the number of filters in each layer. - If `alpha` > 1.0,
      proportionally increases the number of filters in each layer. - If
      `alpha` = 1, default number of filters from the paper are used at each
      layer. Default to 1.0.
    depth_multiplier: Depth multiplier for depthwise convolution. This is
      called the resolution multiplier in the MobileNet paper. Default to 1.0.
    dropout: Dropout rate. Default to 0.001.
    include_top: Boolean, whether to include the fully-connected layer at the
      top of the network. Default to `True`.
    weights: One of `None` (random initialization), 'imagenet' (pre-training
      on ImageNet), or the path to the weights file to be loaded. Default to
      `imagenet`.
    input_tensor: Optional Keras tensor (i.e. output of `layers.Input()`) to
      use as image input for the model. `input_tensor` is useful for sharing
      inputs between multiple different networks. Default to None.
    pooling: Optional pooling mode for feature extraction when `include_top`
      is `False`.
      - `None` (default) means that the output of the model will be
          the 4D tensor output of the last convolutional block.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a 2D tensor.
      - `max` means that global max pooling will be applied.
    classes: Optional number of classes to classify images into, only to be
      specified if `include_top` is True, and if no `weights` argument is
      specified. Defaults to 1000.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.
    **kwargs: For backwards compatibility only.
  Returns:
    A `keras.Model` instance.
  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    global layers
    if 'layers' in kwargs:
        layers = kwargs.pop('layers')
    else:
        layers = VersionAwareLayers()
    if kwargs:
        raise ValueError('Unknown argument(s): %s' % (kwargs, ))
    if not (weights in {'imagenet', None} or file_io.file_exists_v2(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top` '
            'as true, `classes` should be 1000')

    # Determine proper input shape and default size.
    if input_shape is None:
        default_size = 224
    else:
        if backend.image_data_format() == 'channels_first':
            rows = input_shape[1]
            cols = input_shape[2]
        else:
            rows = input_shape[0]
            cols = input_shape[1]

        if rows == cols and rows in [128, 160, 192, 224]:
            default_size = rows
        else:
            default_size = 224

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if backend.image_data_format() == 'channels_last':
        row_axis, col_axis = (0, 1)
    else:
        row_axis, col_axis = (1, 2)
    rows = input_shape[row_axis]
    cols = input_shape[col_axis]

    if weights == 'imagenet':
        if depth_multiplier != 1:
            raise ValueError('If imagenet weights are being loaded, '
                             'depth multiplier must be 1')

        if alpha not in [0.25, 0.50, 0.75, 1.0]:
            raise ValueError('If imagenet weights are being loaded, '
                             'alpha can be one of'
                             '`0.25`, `0.50`, `0.75` or `1.0` only.')

        if rows != cols or rows not in [128, 160, 192, 224]:
            rows = 224
            logging.warning('`input_shape` is undefined or non-square, '
                            'or `rows` is not in [128, 160, 192, 224]. '
                            'Weights for input shape (224, 224) will be'
                            ' loaded as the default.')

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    x = _conv_block(img_input, 32, alpha, strides=(2, 2))
    x = _depthwise_conv_block(x, 64, alpha, depth_multiplier, block_id=1)

    x = _depthwise_conv_block(x,
                              128,
                              alpha,
                              depth_multiplier,
                              strides=(2, 2),
                              block_id=2)
    x = _depthwise_conv_block(x, 128, alpha, depth_multiplier, block_id=3)

    x = _depthwise_conv_block(x,
                              256,
                              alpha,
                              depth_multiplier,
                              strides=(2, 2),
                              block_id=4)
    x = _depthwise_conv_block(x, 256, alpha, depth_multiplier, block_id=5)

    x = _depthwise_conv_block(x,
                              512,
                              alpha,
                              depth_multiplier,
                              strides=(2, 2),
                              block_id=6)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=7)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=8)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=9)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=10)
    x = _depthwise_conv_block(x, 512, alpha, depth_multiplier, block_id=11)

    x = _depthwise_conv_block(x,
                              1024,
                              alpha,
                              depth_multiplier,
                              strides=(2, 2),
                              block_id=12)
    x = _depthwise_conv_block(x, 1024, alpha, depth_multiplier, block_id=13)

    if include_top:
        if backend.image_data_format() == 'channels_first':
            shape = (int(1024 * alpha), 1, 1)
        else:
            shape = (1, 1, int(1024 * alpha))

        x = layers.GlobalAveragePooling2D()(x)
        x = layers.Reshape(shape, name='reshape_1')(x)
        x = layers.Dropout(dropout, name='dropout')(x)
        x = layers.Conv2D(classes, (1, 1), padding='same',
                          name='conv_preds')(x)
        x = layers.Reshape((classes, ), name='reshape_2')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Activation(activation=classifier_activation,
                              name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs,
                           x,
                           name='mobilenet_%0.2f_%s' % (alpha, rows))

    # Load weights.
    if weights == 'imagenet':
        if alpha == 1.0:
            alpha_text = '1_0'
        elif alpha == 0.75:
            alpha_text = '7_5'
        elif alpha == 0.50:
            alpha_text = '5_0'
        else:
            alpha_text = '2_5'

        if include_top:
            model_name = 'mobilenet_%s_%d_tf.h5' % (alpha_text, rows)
            weight_path = BASE_WEIGHT_PATH + model_name
            weights_path = data_utils.get_file(model_name,
                                               weight_path,
                                               cache_subdir='models')
        else:
            model_name = 'mobilenet_%s_%d_tf_no_top.h5' % (alpha_text, rows)
            weight_path = BASE_WEIGHT_PATH + model_name
            weights_path = data_utils.get_file(model_name,
                                               weight_path,
                                               cache_subdir='models')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #18
0
def VGG16(include_top=True,
          weights='imagenet',
          input_tensor=None,
          input_shape=None,
          pooling=None,
          classes=1000,
          l2_reg=0.,
          kl=None,
          classifier_activation='softmax'):
    """Instantiates the VGG19 architecture.
    Optionally loads weights pre-trained on ImageNet.
    Note that the data format convention used by the model is
    the one specified in your Keras config at `~/.keras/keras.json`.
    # Arguments
        include_top: whether to include the 3 fully-connected
            layers at the top of the network.
        weights: one of `None` (random initialization),
              'imagenet' (pre-training on ImageNet),
              or the path to the weights file to be loaded.
        input_tensor: optional Keras tensor
            (i.e. output of `layers.Input()`)
            to use as image input for the model.
        input_shape: optional shape tuple, only to be specified
            if `include_top` is False (otherwise the input shape
            has to be `(224, 224, 3)`
            (with `channels_last` data format)
            or `(3, 224, 224)` (with `channels_first` data format).
            It should have exactly 3 inputs channels,
            and width and height should be no smaller than 32.
            E.g. `(200, 200, 3)` would be one valid value.
        pooling: Optional pooling mode for feature extraction
            when `include_top` is `False`.
            - `None` means that the output of the model will be
                the 4D tensor output of the
                last convolutional block.
            - `avg` means that global average pooling
                will be applied to the output of the
                last convolutional block, and thus
                the output of the model will be a 2D tensor.
            - `max` means that global max pooling will
                be applied.
        classes: optional number of classes to classify images
            into, only to be specified if `include_top` is True, and
            if no `weights` argument is specified.
    # Returns
        A Keras model instance.
    # Raises
        ValueError: in case of invalid argument for `weights`,
            or invalid input shape.
    """
    if not (weights in {'imagenet', None} or os.path.exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')
    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

        # Block 1
    x = tfp.layers.Convolution2DFlipout(64, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block1_conv1')(img_input)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(64, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block1_conv2')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = tfp.layers.Convolution2DFlipout(128, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block2_conv1')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(128, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block2_conv2')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = tfp.layers.Convolution2DFlipout(256, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block3_conv1')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(256, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block3_conv2')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(256, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block3_conv3')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = tfp.layers.Convolution2DFlipout(512, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block4_conv1')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(512, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block4_conv2')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(512, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block4_conv3')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = tfp.layers.Convolution2DFlipout(512, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block5_conv1')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(512, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block5_conv2')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = tfp.layers.Convolution2DFlipout(512, (3, 3),
                                        padding='same',
                                        kernel_divergence_fn=kl,
                                        name='block5_conv3')(x)
    # x = layers.BatchNormalization()(x)
    x = layers.Activation('relu')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    if include_top:
        # Classification block
        x = layers.Flatten(name='flatten')(x)
        x = tfp.layers.DenseFlipout(4096, kernel_divergence_fn=kl,
                                    name='fc1')(x)
        # x = layers.BatchNormalization()(x)
        x = layers.Activation('relu')(x)
        x = tfp.layers.DenseFlipout(4096, kernel_divergence_fn=kl,
                                    name='fc2')(x)
        # x = layers.BatchNormalization()(x)
        x = layers.Activation('relu')(x)

        imagenet_utils.validate_activation(classifier_activation, weights)
        x = tfp.layers.DenseFlipout(classes,
                                    activation=classifier_activation,
                                    name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
            x = tfp.layers.DenseFlipout(4096,
                                        kernel_divergence_fn=kl,
                                        name='fc1')(x)
            # x = layers.BatchNormalization()(x)
            x = layers.Activation('relu')(x)
            x = tfp.layers.DenseFlipout(4096,
                                        kernel_divergence_fn=kl,
                                        name='fc2')(x)
            # x = layers.BatchNormalization()(x)
            x = layers.Activation('relu')(x)

            imagenet_utils.validate_activation(classifier_activation, weights)
            x = tfp.layers.DenseFlipout(classes,
                                        activation=classifier_activation,
                                        name='predictions')(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)
            x = tfp.layers.DenseFlipout(4096,
                                        kernel_divergence_fn=kl,
                                        name='fc1')(x)
            # x = layers.BatchNormalization()(x)
            x = layers.Activation('relu')(x)
            x = tfp.layers.DenseFlipout(4096,
                                        kernel_divergence_fn=kl,
                                        name='fc2')(x)
            # x = layers.BatchNormalization()(x)
            x = layers.Activation('relu')(x)

            imagenet_utils.validate_activation(classifier_activation, weights)
            x = tfp.layers.DenseFlipout(classes,
                                        activation=classifier_activation,
                                        name='predictions')(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input
    # Create model.
    model = training.Model(inputs, x, name='vgg16')

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            weights_path = data_utils.get_file(
                'vgg16_weights_tf_dim_ordering_tf_kernels.h5',
                WEIGHTS_PATH,
                cache_subdir='models',
                file_hash='64373286793e3c8b2b4e3219cbf3544b')
        else:
            weights_path = data_utils.get_file(
                'vgg16_weights_tf_dim_ordering_tf_kernels_notop.h5',
                WEIGHTS_PATH_NO_TOP,
                cache_subdir='models',
                file_hash='6d6bbae143d832006294945121d1f1fc')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #19
0
def Xception(
    include_top=True,
    weights='imagenet',
    input_tensor=None,
    input_shape=None,
    pooling=None,
    classes=1000,
    classifier_activation='softmax',
):
    """Instantiates the Xception architecture.

  Optionally loads weights pre-trained on ImageNet.
  Note that the data format convention used by the model is
  the one specified in your Keras config at `~/.keras/keras.json`.
  Note that the default input image size for this model is 299x299.

  Caution: Be sure to properly pre-process your inputs to the application.
  Please see `applications.xception.preprocess_input` for an example.

  Arguments:
    include_top: whether to include the fully-connected
      layer at the top of the network.
    weights: one of `None` (random initialization),
      'imagenet' (pre-training on ImageNet),
      or the path to the weights file to be loaded.
    input_tensor: optional Keras tensor
      (i.e. output of `layers.Input()`)
      to use as image input for the model.
    input_shape: optional shape tuple, only to be specified
      if `include_top` is False (otherwise the input shape
      has to be `(299, 299, 3)`.
      It should have exactly 3 inputs channels,
      and width and height should be no smaller than 71.
      E.g. `(150, 150, 3)` would be one valid value.
    pooling: Optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` means that the output of the model will be
          the 4D tensor output of the
          last convolutional block.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a 2D tensor.
      - `max` means that global max pooling will
          be applied.
    classes: optional number of classes to classify images
      into, only to be specified if `include_top` is True,
      and if no `weights` argument is specified.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    if not (weights in {'imagenet', None} or os.path.exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=299,
        min_size=71,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    channel_axis = 1 if backend.image_data_format() == 'channels_first' else -1

    x = layers.Conv2D(32, (3, 3),
                      strides=(2, 2),
                      use_bias=False,
                      name='block1_conv1')(img_input)
    x = layers.BatchNormalization(axis=channel_axis, name='block1_conv1_bn')(x)
    x = layers.Activation('relu', name='block1_conv1_act')(x)
    x = layers.Conv2D(64, (3, 3), use_bias=False, name='block1_conv2')(x)
    x = layers.BatchNormalization(axis=channel_axis, name='block1_conv2_bn')(x)
    x = layers.Activation('relu', name='block1_conv2_act')(x)

    residual = layers.Conv2D(128, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.SeparableConv2D(128, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block2_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block2_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block2_sepconv2_act')(x)
    x = layers.SeparableConv2D(128, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block2_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block2_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block2_pool')(x)
    x = layers.add([x, residual])

    residual = layers.Conv2D(256, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.Activation('relu', name='block3_sepconv1_act')(x)
    x = layers.SeparableConv2D(256, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block3_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block3_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block3_sepconv2_act')(x)
    x = layers.SeparableConv2D(256, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block3_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block3_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block3_pool')(x)
    x = layers.add([x, residual])

    residual = layers.Conv2D(728, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.Activation('relu', name='block4_sepconv1_act')(x)
    x = layers.SeparableConv2D(728, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block4_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block4_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block4_sepconv2_act')(x)
    x = layers.SeparableConv2D(728, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block4_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block4_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block4_pool')(x)
    x = layers.add([x, residual])

    for i in range(8):
        residual = x
        prefix = 'block' + str(i + 5)

        x = layers.Activation('relu', name=prefix + '_sepconv1_act')(x)
        x = layers.SeparableConv2D(728, (3, 3),
                                   padding='same',
                                   use_bias=False,
                                   name=prefix + '_sepconv1')(x)
        x = layers.BatchNormalization(axis=channel_axis,
                                      name=prefix + '_sepconv1_bn')(x)
        x = layers.Activation('relu', name=prefix + '_sepconv2_act')(x)
        x = layers.SeparableConv2D(728, (3, 3),
                                   padding='same',
                                   use_bias=False,
                                   name=prefix + '_sepconv2')(x)
        x = layers.BatchNormalization(axis=channel_axis,
                                      name=prefix + '_sepconv2_bn')(x)
        x = layers.Activation('relu', name=prefix + '_sepconv3_act')(x)
        x = layers.SeparableConv2D(728, (3, 3),
                                   padding='same',
                                   use_bias=False,
                                   name=prefix + '_sepconv3')(x)
        x = layers.BatchNormalization(axis=channel_axis,
                                      name=prefix + '_sepconv3_bn')(x)

        x = layers.add([x, residual])

    residual = layers.Conv2D(1024, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.Activation('relu', name='block13_sepconv1_act')(x)
    x = layers.SeparableConv2D(728, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block13_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block13_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block13_sepconv2_act')(x)
    x = layers.SeparableConv2D(1024, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block13_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block13_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block13_pool')(x)
    x = layers.add([x, residual])

    x = layers.SeparableConv2D(1536, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block14_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block14_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block14_sepconv1_act')(x)

    x = layers.SeparableConv2D(2048, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block14_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block14_sepconv2_bn')(x)
    x = layers.Activation('relu', name='block14_sepconv2_act')(x)

    if include_top:
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input
    # Create model.
    model = training.Model(inputs, x, name='xception')

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            weights_path = data_utils.get_file(
                'xception_weights_tf_dim_ordering_tf_kernels.h5',
                TF_WEIGHTS_PATH,
                cache_subdir='models',
                file_hash='0a58e3b7378bc2990ea3b43d5981f1f6')
        else:
            weights_path = data_utils.get_file(
                'xception_weights_tf_dim_ordering_tf_kernels_notop.h5',
                TF_WEIGHTS_PATH_NO_TOP,
                cache_subdir='models',
                file_hash='b0042744bf5b25fce3cb969f33bebb97')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #20
0
def InceptionResNetV2(include_top=True,
                      weights='imagenet',
                      input_tensor=None,
                      input_shape=None,
                      pooling=None,
                      classes=1000,
                      classifier_activation='softmax',
                      **kwargs):
    """Instantiates the Inception-ResNet v2 architecture.

  Reference:
  - [Inception-v4, Inception-ResNet and the Impact of
     Residual Connections on Learning](https://arxiv.org/abs/1602.07261)
    (AAAI 2017)

  Optionally loads weights pre-trained on ImageNet.
  Note that the data format convention used by the model is
  the one specified in your Keras config at `~/.keras/keras.json`.

  Caution: Be sure to properly pre-process your inputs to the application.
  Please see `applications.inception_resnet_v2.preprocess_input` for an example.

  Arguments:
    include_top: whether to include the fully-connected
      layer at the top of the network.
    weights: one of `None` (random initialization),
      'imagenet' (pre-training on ImageNet),
      or the path to the weights file to be loaded.
    input_tensor: optional Keras tensor (i.e. output of `layers.Input()`)
      to use as image input for the model.
    input_shape: optional shape tuple, only to be specified
      if `include_top` is `False` (otherwise the input shape
      has to be `(299, 299, 3)` (with `'channels_last'` data format)
      or `(3, 299, 299)` (with `'channels_first'` data format).
      It should have exactly 3 inputs channels,
      and width and height should be no smaller than 75.
      E.g. `(150, 150, 3)` would be one valid value.
    pooling: Optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` means that the output of the model will be
          the 4D tensor output of the last convolutional block.
      - `'avg'` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a 2D tensor.
      - `'max'` means that global max pooling will be applied.
    classes: optional number of classes to classify images
      into, only to be specified if `include_top` is `True`, and
      if no `weights` argument is specified.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.
    **kwargs: For backwards compatibility only.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    global layers
    if 'layers' in kwargs:
        layers = kwargs.pop('layers')
    else:
        layers = VersionAwareLayers()
    if kwargs:
        raise ValueError('Unknown argument(s): %s' % (kwargs, ))
    if not (weights in {'imagenet', None} or os.path.exists(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=299,
        min_size=75,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    # Stem block: 35 x 35 x 192
    x = conv2d_bn(img_input, 32, 3, strides=2, padding='valid')
    x = conv2d_bn(x, 32, 3, padding='valid')
    x = conv2d_bn(x, 64, 3)
    x = layers.MaxPooling2D(3, strides=2)(x)
    x = conv2d_bn(x, 80, 1, padding='valid')
    x = conv2d_bn(x, 192, 3, padding='valid')
    x = layers.MaxPooling2D(3, strides=2)(x)

    # Mixed 5b (Inception-A block): 35 x 35 x 320
    branch_0 = conv2d_bn(x, 96, 1)
    branch_1 = conv2d_bn(x, 48, 1)
    branch_1 = conv2d_bn(branch_1, 64, 5)
    branch_2 = conv2d_bn(x, 64, 1)
    branch_2 = conv2d_bn(branch_2, 96, 3)
    branch_2 = conv2d_bn(branch_2, 96, 3)
    branch_pool = layers.AveragePooling2D(3, strides=1, padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1)
    branches = [branch_0, branch_1, branch_2, branch_pool]
    channel_axis = 1 if backend.image_data_format() == 'channels_first' else 3
    x = layers.Concatenate(axis=channel_axis, name='mixed_5b')(branches)

    # 10x block35 (Inception-ResNet-A block): 35 x 35 x 320
    for block_idx in range(1, 11):
        x = inception_resnet_block(x,
                                   scale=0.17,
                                   block_type='block35',
                                   block_idx=block_idx)

    # Mixed 6a (Reduction-A block): 17 x 17 x 1088
    branch_0 = conv2d_bn(x, 384, 3, strides=2, padding='valid')
    branch_1 = conv2d_bn(x, 256, 1)
    branch_1 = conv2d_bn(branch_1, 256, 3)
    branch_1 = conv2d_bn(branch_1, 384, 3, strides=2, padding='valid')
    branch_pool = layers.MaxPooling2D(3, strides=2, padding='valid')(x)
    branches = [branch_0, branch_1, branch_pool]
    x = layers.Concatenate(axis=channel_axis, name='mixed_6a')(branches)

    # 20x block17 (Inception-ResNet-B block): 17 x 17 x 1088
    for block_idx in range(1, 21):
        x = inception_resnet_block(x,
                                   scale=0.1,
                                   block_type='block17',
                                   block_idx=block_idx)

    # Mixed 7a (Reduction-B block): 8 x 8 x 2080
    branch_0 = conv2d_bn(x, 256, 1)
    branch_0 = conv2d_bn(branch_0, 384, 3, strides=2, padding='valid')
    branch_1 = conv2d_bn(x, 256, 1)
    branch_1 = conv2d_bn(branch_1, 288, 3, strides=2, padding='valid')
    branch_2 = conv2d_bn(x, 256, 1)
    branch_2 = conv2d_bn(branch_2, 288, 3)
    branch_2 = conv2d_bn(branch_2, 320, 3, strides=2, padding='valid')
    branch_pool = layers.MaxPooling2D(3, strides=2, padding='valid')(x)
    branches = [branch_0, branch_1, branch_2, branch_pool]
    x = layers.Concatenate(axis=channel_axis, name='mixed_7a')(branches)

    # 10x block8 (Inception-ResNet-C block): 8 x 8 x 2080
    for block_idx in range(1, 10):
        x = inception_resnet_block(x,
                                   scale=0.2,
                                   block_type='block8',
                                   block_idx=block_idx)
    x = inception_resnet_block(x,
                               scale=1.,
                               activation=None,
                               block_type='block8',
                               block_idx=10)

    # Final convolution block: 8 x 8 x 1536
    x = conv2d_bn(x, 1536, 1, name='conv_7b')

    if include_top:
        # Classification block
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs, x, name='inception_resnet_v2')

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            fname = 'inception_resnet_v2_weights_tf_dim_ordering_tf_kernels.h5'
            weights_path = data_utils.get_file(
                fname,
                BASE_WEIGHT_URL + fname,
                cache_subdir='models',
                file_hash='e693bd0210a403b3192acc6073ad2e96')
        else:
            fname = ('inception_resnet_v2_weights_'
                     'tf_dim_ordering_tf_kernels_notop.h5')
            weights_path = data_utils.get_file(
                fname,
                BASE_WEIGHT_URL + fname,
                cache_subdir='models',
                file_hash='d19885ff4a710c122648d3b5c3b684e4')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #21
0
def MobileNetV3(stack_fn,
                last_point_ch,
                input_shape=None,
                alpha=1.0,
                model_type='large',
                minimalistic=False,
                include_top=True,
                weights='imagenet',
                input_tensor=None,
                classes=1000,
                pooling=None,
                dropout_rate=0.2,
                classifier_activation='softmax'):
    if not (weights in {'imagenet', None} or file_io.file_exists_v2(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top` '
            'as true, `classes` should be 1000')

    # Determine proper input shape and default size.
    # If both input_shape and input_tensor are used, they should match
    if input_shape is not None and input_tensor is not None:
        try:
            is_input_t_tensor = backend.is_keras_tensor(input_tensor)
        except ValueError:
            try:
                is_input_t_tensor = backend.is_keras_tensor(
                    layer_utils.get_source_inputs(input_tensor))
            except ValueError:
                raise ValueError('input_tensor: ', input_tensor,
                                 'is not type input_tensor')
        if is_input_t_tensor:
            if backend.image_data_format() == 'channels_first':
                if backend.int_shape(input_tensor)[1] != input_shape[1]:
                    raise ValueError(
                        'input_shape: ', input_shape, 'and input_tensor: ',
                        input_tensor,
                        'do not meet the same shape requirements')
            else:
                if backend.int_shape(input_tensor)[2] != input_shape[1]:
                    raise ValueError(
                        'input_shape: ', input_shape, 'and input_tensor: ',
                        input_tensor,
                        'do not meet the same shape requirements')
        else:
            raise ValueError('input_tensor specified: ', input_tensor,
                             'is not a keras tensor')

    # If input_shape is None, infer shape from input_tensor
    if input_shape is None and input_tensor is not None:

        try:
            backend.is_keras_tensor(input_tensor)
        except ValueError:
            raise ValueError('input_tensor: ', input_tensor, 'is type: ',
                             type(input_tensor), 'which is not a valid type')

        if backend.is_keras_tensor(input_tensor):
            if backend.image_data_format() == 'channels_first':
                rows = backend.int_shape(input_tensor)[2]
                cols = backend.int_shape(input_tensor)[3]
                input_shape = (3, cols, rows)
            else:
                rows = backend.int_shape(input_tensor)[1]
                cols = backend.int_shape(input_tensor)[2]
                input_shape = (cols, rows, 3)
    # If input_shape is None and input_tensor is None using standart shape
    if input_shape is None and input_tensor is None:
        input_shape = (None, None, 3)

    if backend.image_data_format() == 'channels_last':
        row_axis, col_axis = (0, 1)
    else:
        row_axis, col_axis = (1, 2)
    rows = input_shape[row_axis]
    cols = input_shape[col_axis]
    if rows and cols and (rows < 32 or cols < 32):
        raise ValueError(
            'Input size must be at least 32x32; got `input_shape=' +
            str(input_shape) + '`')
    if weights == 'imagenet':
        if (not minimalistic and alpha not in [0.75, 1.0]
                or minimalistic and alpha != 1.0):
            raise ValueError(
                'If imagenet weights are being loaded, '
                'alpha can be one of `0.75`, `1.0` for non minimalistic'
                ' or `1.0` for minimalistic only.')

        if rows != cols or rows != 224:
            logging.warning('`input_shape` is undefined or non-square, '
                            'or `rows` is not 224.'
                            ' Weights for input shape (224, 224) will be'
                            ' loaded as the default.')

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    channel_axis = 1 if backend.image_data_format() == 'channels_first' else -1

    if minimalistic:
        kernel = 3
        activation = relu
        se_ratio = None
    else:
        kernel = 5
        activation = hard_swish
        se_ratio = 0.25

    x = img_input
    x = layers.Rescaling(scale=1. / 127.5, offset=-1.)(x)
    x = layers.Conv2D(16,
                      kernel_size=3,
                      strides=(2, 2),
                      padding='same',
                      use_bias=False,
                      name='Conv')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  epsilon=1e-3,
                                  momentum=0.999,
                                  name='Conv/BatchNorm')(x)
    x = activation(x)

    x = stack_fn(x, kernel, activation, se_ratio)

    last_conv_ch = _depth(backend.int_shape(x)[channel_axis] * 6)

    # if the width multiplier is greater than 1 we
    # increase the number of output channels
    if alpha > 1.0:
        last_point_ch = _depth(last_point_ch * alpha)
    x = layers.Conv2D(last_conv_ch,
                      kernel_size=1,
                      padding='same',
                      use_bias=False,
                      name='Conv_1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  epsilon=1e-3,
                                  momentum=0.999,
                                  name='Conv_1/BatchNorm')(x)
    x = activation(x)
    x = layers.GlobalAveragePooling2D(keepdims=True)(x)
    x = layers.Conv2D(last_point_ch,
                      kernel_size=1,
                      padding='same',
                      use_bias=True,
                      name='Conv_2')(x)
    x = activation(x)

    if include_top:
        if dropout_rate > 0:
            x = layers.Dropout(dropout_rate)(x)
        x = layers.Conv2D(classes,
                          kernel_size=1,
                          padding='same',
                          name='Logits')(x)
        x = layers.Flatten()(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Activation(activation=classifier_activation,
                              name='Predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D(name='max_pool')(x)
    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = models.Model(inputs, x, name='MobilenetV3' + model_type)

    # Load weights.
    if weights == 'imagenet':
        model_name = '{}{}_224_{}_float'.format(
            model_type, '_minimalistic' if minimalistic else '', str(alpha))
        if include_top:
            file_name = 'weights_mobilenet_v3_' + model_name + '.h5'
            file_hash = WEIGHTS_HASHES[model_name][0]
        else:
            file_name = 'weights_mobilenet_v3_' + model_name + '_no_top.h5'
            file_hash = WEIGHTS_HASHES[model_name][1]
        weights_path = data_utils.get_file(file_name,
                                           BASE_WEIGHT_PATH + file_name,
                                           cache_subdir='models',
                                           file_hash=file_hash)
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #22
0
def VGG16(include_top=True,
          weights='imagenet',
          input_tensor=None,
          input_shape=None,
          pooling=None,
          classes=1000,
          classifier_activation='softmax'):
    """Instantiates the VGG16 model.

  Reference:
  - [Very Deep Convolutional Networks for Large-Scale Image Recognition](
  https://arxiv.org/abs/1409.1556) (ICLR 2015)

  For image classification use cases, see
  [this page for detailed examples](
    https://keras.io/api/applications/#usage-examples-for-image-classification-models).

  For transfer learning use cases, make sure to read the
  [guide to transfer learning & fine-tuning](
    https://keras.io/guides/transfer_learning/).

  The default input size for this model is 224x224.

  Note: each Keras Application expects a specific kind of input preprocessing.
  For VGG16, call `tf.keras.applications.vgg16.preprocess_input` on your
  inputs before passing them to the model.
  `vgg16.preprocess_input` will convert the input images from RGB to BGR,
  then will zero-center each color channel with respect to the ImageNet dataset,
  without scaling.

  Args:
      include_top: whether to include the 3 fully-connected
          layers at the top of the network.
      weights: one of `None` (random initialization),
            'imagenet' (pre-training on ImageNet),
            or the path to the weights file to be loaded.
      input_tensor: optional Keras tensor
          (i.e. output of `layers.Input()`)
          to use as image input for the model.
      input_shape: optional shape tuple, only to be specified
          if `include_top` is False (otherwise the input shape
          has to be `(224, 224, 3)`
          (with `channels_last` data format)
          or `(3, 224, 224)` (with `channels_first` data format).
          It should have exactly 3 input channels,
          and width and height should be no smaller than 32.
          E.g. `(200, 200, 3)` would be one valid value.
      pooling: Optional pooling mode for feature extraction
          when `include_top` is `False`.
          - `None` means that the output of the model will be
              the 4D tensor output of the
              last convolutional block.
          - `avg` means that global average pooling
              will be applied to the output of the
              last convolutional block, and thus
              the output of the model will be a 2D tensor.
          - `max` means that global max pooling will
              be applied.
      classes: optional number of classes to classify images
          into, only to be specified if `include_top` is True, and
          if no `weights` argument is specified.
      classifier_activation: A `str` or callable. The activation function to use
          on the "top" layer. Ignored unless `include_top=True`. Set
          `classifier_activation=None` to return the logits of the "top" layer.
          When loading pretrained weights, `classifier_activation` can only
          be `None` or `"softmax"`.

  Returns:
    A `keras.Model` instance.
  """
    if not (weights in {'imagenet', None} or file_io.file_exists_v2(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')
    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor
    # Block 1
    x = layers.Conv2D(64, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block1_conv1')(img_input)
    x = layers.Conv2D(64, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block1_conv2')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = layers.Conv2D(128, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block2_conv1')(x)
    x = layers.Conv2D(128, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block2_conv2')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv1')(x)
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv2')(x)
    x = layers.Conv2D(256, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block3_conv3')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv1')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv2')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block4_conv3')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv1')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv2')(x)
    x = layers.Conv2D(512, (3, 3),
                      activation='relu',
                      padding='same',
                      name='block5_conv3')(x)
    x = layers.MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    if include_top:
        # Classification block
        x = layers.Flatten(name='flatten')(x)
        x = layers.Dense(4096, activation='relu', name='fc1')(x)
        x = layers.Dense(4096, activation='relu', name='fc2')(x)

        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input
    # Create model.
    model = training.Model(inputs, x, name='vgg16')

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            weights_path = data_utils.get_file(
                'vgg16_weights_tf_dim_ordering_tf_kernels.h5',
                WEIGHTS_PATH,
                cache_subdir='models',
                file_hash='64373286793e3c8b2b4e3219cbf3544b')
        else:
            weights_path = data_utils.get_file(
                'vgg16_weights_tf_dim_ordering_tf_kernels_notop.h5',
                WEIGHTS_PATH_NO_TOP,
                cache_subdir='models',
                file_hash='6d6bbae143d832006294945121d1f1fc')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #23
0
def DenseNet(blocks,
             include_top=True,
             weights='imagenet',
             input_tensor=None,
             input_shape=None,
             pooling=None,
             classes=1000,
             classifier_activation='softmax'):
    """Instantiates the DenseNet architecture.

  Reference:
  - [Densely Connected Convolutional Networks](
      https://arxiv.org/abs/1608.06993) (CVPR 2017)

  Optionally loads weights pre-trained on ImageNet.
  Note that the data format convention used by the model is
  the one specified in your Keras config at `~/.keras/keras.json`.

  Note: each Keras Application expects a specific kind of input preprocessing.
  For DenseNet, call `tf.keras.applications.densenet.preprocess_input` on your
  inputs before passing them to the model.

  Args:
    blocks: numbers of building blocks for the four dense layers.
    include_top: whether to include the fully-connected
      layer at the top of the network.
    weights: one of `None` (random initialization),
      'imagenet' (pre-training on ImageNet),
      or the path to the weights file to be loaded.
    input_tensor: optional Keras tensor
      (i.e. output of `layers.Input()`)
      to use as image input for the model.
    input_shape: optional shape tuple, only to be specified
      if `include_top` is False (otherwise the input shape
      has to be `(224, 224, 3)` (with `'channels_last'` data format)
      or `(3, 224, 224)` (with `'channels_first'` data format).
      It should have exactly 3 inputs channels,
      and width and height should be no smaller than 32.
      E.g. `(200, 200, 3)` would be one valid value.
    pooling: optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` means that the output of the model will be
          the 4D tensor output of the
          last convolutional block.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a 2D tensor.
      - `max` means that global max pooling will
          be applied.
    classes: optional number of classes to classify images
      into, only to be specified if `include_top` is True, and
      if no `weights` argument is specified.
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: in case of invalid argument for `weights`,
      or invalid input shape.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    if not (weights in {'imagenet', None} or file_io.file_exists_v2(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top`'
            ' as true, `classes` should be 1000')

    # Determine proper input shape
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=224,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=include_top,
        weights=weights)

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    x = layers.ZeroPadding2D(padding=((3, 3), (3, 3)))(img_input)
    x = layers.Conv2D(64, 7, strides=2, use_bias=False, name='conv1/conv')(x)
    x = layers.BatchNormalization(axis=bn_axis,
                                  epsilon=1.001e-5,
                                  name='conv1/bn')(x)
    x = layers.Activation('relu', name='conv1/relu')(x)
    x = layers.ZeroPadding2D(padding=((1, 1), (1, 1)))(x)
    x = layers.MaxPooling2D(3, strides=2, name='pool1')(x)

    x = dense_block(x, blocks[0], name='conv2')
    x = transition_block(x, 0.5, name='pool2')
    x = dense_block(x, blocks[1], name='conv3')
    x = transition_block(x, 0.5, name='pool3')
    x = dense_block(x, blocks[2], name='conv4')
    x = transition_block(x, 0.5, name='pool4')
    x = dense_block(x, blocks[3], name='conv5')

    x = layers.BatchNormalization(axis=bn_axis, epsilon=1.001e-5, name='bn')(x)
    x = layers.Activation('relu', name='relu')(x)

    if include_top:
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)

        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D(name='max_pool')(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    if blocks == [6, 12, 24, 16]:
        model = training.Model(inputs, x, name='densenet121')
    elif blocks == [6, 12, 32, 32]:
        model = training.Model(inputs, x, name='densenet169')
    elif blocks == [6, 12, 48, 32]:
        model = training.Model(inputs, x, name='densenet201')
    else:
        model = training.Model(inputs, x, name='densenet')

    # Load weights.
    if weights == 'imagenet':
        if include_top:
            if blocks == [6, 12, 24, 16]:
                weights_path = data_utils.get_file(
                    'densenet121_weights_tf_dim_ordering_tf_kernels.h5',
                    DENSENET121_WEIGHT_PATH,
                    cache_subdir='models',
                    file_hash='9d60b8095a5708f2dcce2bca79d332c7')
            elif blocks == [6, 12, 32, 32]:
                weights_path = data_utils.get_file(
                    'densenet169_weights_tf_dim_ordering_tf_kernels.h5',
                    DENSENET169_WEIGHT_PATH,
                    cache_subdir='models',
                    file_hash='d699b8f76981ab1b30698df4c175e90b')
            elif blocks == [6, 12, 48, 32]:
                weights_path = data_utils.get_file(
                    'densenet201_weights_tf_dim_ordering_tf_kernels.h5',
                    DENSENET201_WEIGHT_PATH,
                    cache_subdir='models',
                    file_hash='1ceb130c1ea1b78c3bf6114dbdfd8807')
        else:
            if blocks == [6, 12, 24, 16]:
                weights_path = data_utils.get_file(
                    'densenet121_weights_tf_dim_ordering_tf_kernels_notop.h5',
                    DENSENET121_WEIGHT_PATH_NO_TOP,
                    cache_subdir='models',
                    file_hash='30ee3e1110167f948a6b9946edeeb738')
            elif blocks == [6, 12, 32, 32]:
                weights_path = data_utils.get_file(
                    'densenet169_weights_tf_dim_ordering_tf_kernels_notop.h5',
                    DENSENET169_WEIGHT_PATH_NO_TOP,
                    cache_subdir='models',
                    file_hash='b8c4d4c20dd625c148057b9ff1c1176b')
            elif blocks == [6, 12, 48, 32]:
                weights_path = data_utils.get_file(
                    'densenet201_weights_tf_dim_ordering_tf_kernels_notop.h5',
                    DENSENET201_WEIGHT_PATH_NO_TOP,
                    cache_subdir='models',
                    file_hash='c13680b51ded0fb44dff2d8f86ac8bb1')
        model.load_weights(weights_path)
    elif weights is not None:
        model.load_weights(weights)

    return model
Example #24
0
def InceptionResNetV2(input_shape=None):
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=299,
        min_size=75,
        data_format=backend.image_data_format(),
        require_flatten=True)

    img_input = layers.Input(shape=input_shape)

    # Stem block: 35 x 35 x 192
    x = conv2d_bn(img_input, 32, 3, strides=2, padding='valid')
    x = conv2d_bn(x, 32, 3, padding='valid')
    x = conv2d_bn(x, 64, 3)
    x = layers.MaxPooling2D(3, strides=2)(x)
    x = conv2d_bn(x, 80, 1, padding='valid')
    x = conv2d_bn(x, 192, 3, padding='valid')
    x = layers.MaxPooling2D(3, strides=2)(x)

    # Mixed 5b (Inception-A block): 35 x 35 x 320
    branch_0 = conv2d_bn(x, 96, 1)
    branch_1 = conv2d_bn(x, 48, 1)
    branch_1 = conv2d_bn(branch_1, 64, 5)
    branch_2 = conv2d_bn(x, 64, 1)
    branch_2 = conv2d_bn(branch_2, 96, 3)
    branch_2 = conv2d_bn(branch_2, 96, 3)
    branch_pool = layers.AveragePooling2D(3, strides=1, padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1)
    branches = [branch_0, branch_1, branch_2, branch_pool]
    channel_axis = 1 if backend.image_data_format() == 'channels_first' else 3
    x = layers.Concatenate(axis=channel_axis, name='mixed_5b')(branches)

    # 10x block35 (Inception-ResNet-A block): 35 x 35 x 320
    for block_idx in range(1, 11):
        x = inception_resnet_block(x,
                                   scale=0.17,
                                   block_type='block35',
                                   block_idx=block_idx)

    # Mixed 6a (Reduction-A block): 17 x 17 x 1088
    branch_0 = conv2d_bn(x, 384, 3, strides=2, padding='valid')
    branch_1 = conv2d_bn(x, 256, 1)
    branch_1 = conv2d_bn(branch_1, 256, 3)
    branch_1 = conv2d_bn(branch_1, 384, 3, strides=2, padding='valid')
    branch_pool = layers.MaxPooling2D(3, strides=2, padding='valid')(x)
    branches = [branch_0, branch_1, branch_pool]
    x = layers.Concatenate(axis=channel_axis, name='mixed_6a')(branches)

    # 20x block17 (Inception-ResNet-B block): 17 x 17 x 1088
    for block_idx in range(1, 21):
        x = inception_resnet_block(x,
                                   scale=0.1,
                                   block_type='block17',
                                   block_idx=block_idx)

    # Mixed 7a (Reduction-B block): 8 x 8 x 2080
    branch_0 = conv2d_bn(x, 256, 1)
    branch_0 = conv2d_bn(branch_0, 384, 3, strides=2, padding='valid')
    branch_1 = conv2d_bn(x, 256, 1)
    branch_1 = conv2d_bn(branch_1, 288, 3, strides=2, padding='valid')
    branch_2 = conv2d_bn(x, 256, 1)
    branch_2 = conv2d_bn(branch_2, 288, 3)
    branch_2 = conv2d_bn(branch_2, 320, 3, strides=2, padding='valid')
    branch_pool = layers.MaxPooling2D(3, strides=2, padding='valid')(x)
    branches = [branch_0, branch_1, branch_2, branch_pool]
    x = layers.Concatenate(axis=channel_axis, name='mixed_7a')(branches)

    # 10x block8 (Inception-ResNet-C block): 8 x 8 x 2080
    for block_idx in range(1, 10):
        x = inception_resnet_block(x,
                                   scale=0.2,
                                   block_type='block8',
                                   block_idx=block_idx)
    x = inception_resnet_block(x,
                               scale=1.,
                               activation=None,
                               block_type='block8',
                               block_idx=10)

    # Final convolution block: 8 x 8 x 1536
    x = conv2d_bn(x, 1536, 1, name='conv_7b')

    # Classification block
    x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    # Create model.
    model = training.Model(img_input, x, name='inception_resnet_v2')

    return model
Example #25
0
def NASNet(input_shape=None,
           penultimate_filters=4032,
           num_blocks=6,
           stem_block_filters=96,
           skip_reduction=True,
           filter_multiplier=2,
           include_top=True,
           weights=None,
           input_tensor=None,
           pooling=None,
           classes=1000,
           default_size=None,
           classifier_activation='softmax'):
    """Instantiates a NASNet model.

  Reference:
  - [Learning Transferable Architectures for Scalable Image Recognition](
      https://arxiv.org/abs/1707.07012) (CVPR 2018)

  Optionally loads weights pre-trained on ImageNet.
  Note that the data format convention used by the model is
  the one specified in your Keras config at `~/.keras/keras.json`.

  Caution: Be sure to properly pre-process your inputs to the application.
  Please see `applications.nasnet.preprocess_input` for an example.

  Arguments:
    input_shape: Optional shape tuple, the input shape
      is by default `(331, 331, 3)` for NASNetLarge and
      `(224, 224, 3)` for NASNetMobile.
      It should have exactly 3 input channels,
      and width and height should be no smaller than 32.
      E.g. `(224, 224, 3)` would be one valid value.
    penultimate_filters: Number of filters in the penultimate layer.
      NASNet models use the notation `NASNet (N @ P)`, where:
          -   N is the number of blocks
          -   P is the number of penultimate filters
    num_blocks: Number of repeated blocks of the NASNet model.
      NASNet models use the notation `NASNet (N @ P)`, where:
          -   N is the number of blocks
          -   P is the number of penultimate filters
    stem_block_filters: Number of filters in the initial stem block
    skip_reduction: Whether to skip the reduction step at the tail
      end of the network.
    filter_multiplier: Controls the width of the network.
      - If `filter_multiplier` < 1.0, proportionally decreases the number
          of filters in each layer.
      - If `filter_multiplier` > 1.0, proportionally increases the number
          of filters in each layer.
      - If `filter_multiplier` = 1, default number of filters from the
           paper are used at each layer.
    include_top: Whether to include the fully-connected
      layer at the top of the network.
    weights: `None` (random initialization) or
        `imagenet` (ImageNet weights)
    input_tensor: Optional Keras tensor (i.e. output of
      `layers.Input()`)
      to use as image input for the model.
    pooling: Optional pooling mode for feature extraction
      when `include_top` is `False`.
      - `None` means that the output of the model
          will be the 4D tensor output of the
          last convolutional block.
      - `avg` means that global average pooling
          will be applied to the output of the
          last convolutional block, and thus
          the output of the model will be a
          2D tensor.
      - `max` means that global max pooling will
          be applied.
    classes: Optional number of classes to classify images
      into, only to be specified if `include_top` is True, and
      if no `weights` argument is specified.
    default_size: Specifies the default image size of the model
    classifier_activation: A `str` or callable. The activation function to use
      on the "top" layer. Ignored unless `include_top=True`. Set
      `classifier_activation=None` to return the logits of the "top" layer.

  Returns:
    A `keras.Model` instance.

  Raises:
    ValueError: In case of invalid argument for `weights`,
      invalid input shape or invalid `penultimate_filters` value.
    ValueError: if `classifier_activation` is not `softmax` or `None` when
      using a pretrained top layer.
  """
    if not (weights in {'imagenet', None} or file_io.file_exists_v2(weights)):
        raise ValueError('The `weights` argument should be either '
                         '`None` (random initialization), `imagenet` '
                         '(pre-training on ImageNet), '
                         'or the path to the weights file to be loaded.')

    if weights == 'imagenet' and include_top and classes != 1000:
        raise ValueError(
            'If using `weights` as `"imagenet"` with `include_top` '
            'as true, `classes` should be 1000')

    if (isinstance(input_shape, tuple) and None in input_shape
            and weights == 'imagenet'):
        raise ValueError('When specifying the input shape of a NASNet'
                         ' and loading `ImageNet` weights, '
                         'the input_shape argument must be static '
                         '(no None entries). Got: `input_shape=' +
                         str(input_shape) + '`.')

    if default_size is None:
        default_size = 331

    # Determine proper input shape and default size.
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=True,
        weights=weights)

    if backend.image_data_format() != 'channels_last':
        logging.warning(
            'The NASNet family of models is only available '
            'for the input data format "channels_last" '
            '(width, height, channels). '
            'However your settings specify the default '
            'data format "channels_first" (channels, width, height).'
            ' You should set `image_data_format="channels_last"` '
            'in your Keras config located at ~/.keras/keras.json. '
            'The model being returned right now will expect inputs '
            'to follow the "channels_last" data format.')
        backend.set_image_data_format('channels_last')
        old_data_format = 'channels_first'
    else:
        old_data_format = None

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if penultimate_filters % (24 * (filter_multiplier**2)) != 0:
        raise ValueError(
            'For NASNet-A models, the `penultimate_filters` must be a multiple '
            'of 24 * (`filter_multiplier` ** 2). Current value: %d' %
            penultimate_filters)

    channel_dim = 1 if backend.image_data_format() == 'channels_first' else -1
    filters = penultimate_filters // 24

    x = layers.Conv2D(stem_block_filters, (3, 3),
                      strides=(2, 2),
                      padding='valid',
                      use_bias=False,
                      name='stem_conv1',
                      kernel_initializer='he_normal')(img_input)

    x = layers.BatchNormalization(axis=channel_dim,
                                  momentum=0.9997,
                                  epsilon=1e-3,
                                  name='stem_bn1')(x)

    p = None
    x, p = _reduction_a_cell(x,
                             p,
                             filters // (filter_multiplier**2),
                             block_id='stem_1')
    x, p = _reduction_a_cell(x,
                             p,
                             filters // filter_multiplier,
                             block_id='stem_2')

    for i in range(num_blocks):
        x, p = _normal_a_cell(x, p, filters, block_id='%d' % (i))

    x, p0 = _reduction_a_cell(x,
                              p,
                              filters * filter_multiplier,
                              block_id='reduce_%d' % (num_blocks))

    p = p0 if not skip_reduction else p

    for i in range(num_blocks):
        x, p = _normal_a_cell(x,
                              p,
                              filters * filter_multiplier,
                              block_id='%d' % (num_blocks + i + 1))

    x, p0 = _reduction_a_cell(x,
                              p,
                              filters * filter_multiplier**2,
                              block_id='reduce_%d' % (2 * num_blocks))

    p = p0 if not skip_reduction else p

    for i in range(num_blocks):
        x, p = _normal_a_cell(x,
                              p,
                              filters * filter_multiplier**2,
                              block_id='%d' % (2 * num_blocks + i + 1))

    x = layers.Activation('relu')(x)

    if include_top:
        x = layers.GlobalAveragePooling2D()(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D()(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D()(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    model = training.Model(inputs, x, name='NASNet')

    # Load weights.
    if weights == 'imagenet':
        if default_size == 224:  # mobile version
            if include_top:
                weights_path = data_utils.get_file(
                    'nasnet_mobile.h5',
                    NASNET_MOBILE_WEIGHT_PATH,
                    cache_subdir='models',
                    file_hash='020fb642bf7360b370c678b08e0adf61')
            else:
                weights_path = data_utils.get_file(
                    'nasnet_mobile_no_top.h5',
                    NASNET_MOBILE_WEIGHT_PATH_NO_TOP,
                    cache_subdir='models',
                    file_hash='1ed92395b5b598bdda52abe5c0dbfd63')
            model.load_weights(weights_path)
        elif default_size == 331:  # large version
            if include_top:
                weights_path = data_utils.get_file(
                    'nasnet_large.h5',
                    NASNET_LARGE_WEIGHT_PATH,
                    cache_subdir='models',
                    file_hash='11577c9a518f0070763c2b964a382f17')
            else:
                weights_path = data_utils.get_file(
                    'nasnet_large_no_top.h5',
                    NASNET_LARGE_WEIGHT_PATH_NO_TOP,
                    cache_subdir='models',
                    file_hash='d81d89dc07e6e56530c4e77faddd61b5')
            model.load_weights(weights_path)
        else:
            raise ValueError(
                'ImageNet weights can only be loaded with NASNetLarge'
                ' or NASNetMobile')
    elif weights is not None:
        model.load_weights(weights)

    if old_data_format:
        backend.set_image_data_format(old_data_format)

    return model
Example #26
0
def Xception(input_shape=None):
    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=299,
        min_size=71,
        data_format=backend.image_data_format(),
        require_flatten=True)

    img_input = layers.Input(shape=input_shape)

    channel_axis = 1 if backend.image_data_format() == 'channels_first' else -1

    x = layers.Conv2D(32, (3, 3),
                      strides=(2, 2),
                      use_bias=False,
                      name='block1_conv1')(img_input)
    x = layers.BatchNormalization(axis=channel_axis, name='block1_conv1_bn')(x)
    x = layers.Activation('relu', name='block1_conv1_act')(x)
    x = layers.Conv2D(64, (3, 3), use_bias=False, name='block1_conv2')(x)
    x = layers.BatchNormalization(axis=channel_axis, name='block1_conv2_bn')(x)
    x = layers.Activation('relu', name='block1_conv2_act')(x)

    residual = layers.Conv2D(128, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.SeparableConv2D(128, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block2_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block2_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block2_sepconv2_act')(x)
    x = layers.SeparableConv2D(128, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block2_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block2_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block2_pool')(x)
    x = layers.add([x, residual])

    residual = layers.Conv2D(256, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.Activation('relu', name='block3_sepconv1_act')(x)
    x = layers.SeparableConv2D(256, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block3_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block3_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block3_sepconv2_act')(x)
    x = layers.SeparableConv2D(256, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block3_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block3_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block3_pool')(x)
    x = layers.add([x, residual])

    residual = layers.Conv2D(728, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.Activation('relu', name='block4_sepconv1_act')(x)
    x = layers.SeparableConv2D(728, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block4_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block4_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block4_sepconv2_act')(x)
    x = layers.SeparableConv2D(728, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block4_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block4_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block4_pool')(x)
    x = layers.add([x, residual])

    for i in range(8):
        residual = x
        prefix = 'block' + str(i + 5)

        x = layers.Activation('relu', name=prefix + '_sepconv1_act')(x)
        x = layers.SeparableConv2D(728, (3, 3),
                                   padding='same',
                                   use_bias=False,
                                   name=prefix + '_sepconv1')(x)
        x = layers.BatchNormalization(axis=channel_axis,
                                      name=prefix + '_sepconv1_bn')(x)
        x = layers.Activation('relu', name=prefix + '_sepconv2_act')(x)
        x = layers.SeparableConv2D(728, (3, 3),
                                   padding='same',
                                   use_bias=False,
                                   name=prefix + '_sepconv2')(x)
        x = layers.BatchNormalization(axis=channel_axis,
                                      name=prefix + '_sepconv2_bn')(x)
        x = layers.Activation('relu', name=prefix + '_sepconv3_act')(x)
        x = layers.SeparableConv2D(728, (3, 3),
                                   padding='same',
                                   use_bias=False,
                                   name=prefix + '_sepconv3')(x)
        x = layers.BatchNormalization(axis=channel_axis,
                                      name=prefix + '_sepconv3_bn')(x)

        x = layers.add([x, residual])

    residual = layers.Conv2D(1024, (1, 1),
                             strides=(2, 2),
                             padding='same',
                             use_bias=False)(x)
    residual = layers.BatchNormalization(axis=channel_axis)(residual)

    x = layers.Activation('relu', name='block13_sepconv1_act')(x)
    x = layers.SeparableConv2D(728, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block13_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block13_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block13_sepconv2_act')(x)
    x = layers.SeparableConv2D(1024, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block13_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block13_sepconv2_bn')(x)

    x = layers.MaxPooling2D((3, 3),
                            strides=(2, 2),
                            padding='same',
                            name='block13_pool')(x)
    x = layers.add([x, residual])

    x = layers.SeparableConv2D(1536, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block14_sepconv1')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block14_sepconv1_bn')(x)
    x = layers.Activation('relu', name='block14_sepconv1_act')(x)

    x = layers.SeparableConv2D(2048, (3, 3),
                               padding='same',
                               use_bias=False,
                               name='block14_sepconv2')(x)
    x = layers.BatchNormalization(axis=channel_axis,
                                  name='block14_sepconv2_bn')(x)
    x = layers.Activation('relu', name='block14_sepconv2_act')(x)

    x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    # Create model.
    model = training.Model(img_input, x, name='xception')

    return model
Example #27
0
def EfficientNet(width_coefficient,
                 depth_coefficient,
                 default_size,
                 dropout_rate=0.2,
                 drop_connect_rate=0.2,
                 depth_divisor=8,
                 activation='swish',
                 blocks_args='default',
                 model_name='efficientnet',
                 include_top=True,
                 weights='imagenet',
                 input_tensor=None,
                 input_shape=None,
                 pooling=None,
                 classes=1000,
                 classifier_activation='softmax'):

    if blocks_args == 'default':
        blocks_args = DEFAULT_BLOCKS_ARGS

    if input_tensor is None:
        img_input = layers.Input(shape=input_shape)
    else:
        if not backend.is_keras_tensor(input_tensor):
            img_input = layers.Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1

    def round_filters(filters, divisor=depth_divisor):
        """Round number of filters based on depth multiplier."""
        filters *= width_coefficient
        new_filters = max(divisor,
                          int(filters + divisor / 2) // divisor * divisor)
        # Make sure that round down does not go down by more than 10%.
        if new_filters < 0.9 * filters:
            new_filters += divisor
        return int(new_filters)

    def round_repeats(repeats):
        """Round number of repeats based on depth multiplier."""
        return int(math.ceil(depth_coefficient * repeats))

    # Build stem
    x = img_input
    x = layers.Rescaling(1. / 255.)(x)
    x = layers.Normalization(axis=bn_axis)(x)

    x = layers.ZeroPadding2D(padding=imagenet_utils.correct_pad(x, 3),
                             name='stem_conv_pad')(x)
    x = layers.Conv2D(round_filters(32),
                      3,
                      strides=2,
                      padding='valid',
                      use_bias=False,
                      kernel_initializer=CONV_KERNEL_INITIALIZER,
                      name='stem_conv')(x)
    x = layers.BatchNormalization(axis=bn_axis, name='stem_bn')(x)
    x = layers.Activation(activation, name='stem_activation')(x)

    # Build blocks
    blocks_args = copy.deepcopy(blocks_args)

    b = 0
    blocks = float(sum(round_repeats(args['repeats']) for args in blocks_args))
    for (i, args) in enumerate(blocks_args):
        assert args['repeats'] > 0
        # Update block input and output filters based on depth multiplier.
        args['filters_in'] = round_filters(args['filters_in'])
        args['filters_out'] = round_filters(args['filters_out'])

        for j in range(round_repeats(args.pop('repeats'))):
            # The first block needs to take care of stride and filter size increase.
            if j > 0:
                args['strides'] = 1
                args['filters_in'] = args['filters_out']
            x = block(x,
                      activation,
                      drop_connect_rate * b / blocks,
                      name='block{}{}_'.format(i + 1, chr(j + 97)),
                      **args)
            b += 1

    # Build top
    x = layers.Conv2D(round_filters(1280),
                      1,
                      padding='same',
                      use_bias=False,
                      kernel_initializer=CONV_KERNEL_INITIALIZER,
                      name='top_conv')(x)
    x = layers.BatchNormalization(axis=bn_axis, name='top_bn')(x)
    x = layers.Activation(activation, name='top_activation')(x)
    if include_top:
        x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        if dropout_rate > 0:
            x = layers.Dropout(dropout_rate, name='top_dropout')(x)
        imagenet_utils.validate_activation(classifier_activation, weights)
        x = layers.Dense(classes,
                         activation=classifier_activation,
                         kernel_initializer=DENSE_KERNEL_INITIALIZER,
                         name='predictions')(x)
    else:
        if pooling == 'avg':
            x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
        elif pooling == 'max':
            x = layers.GlobalMaxPooling2D(name='max_pool')(x)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = layer_utils.get_source_inputs(input_tensor)
    else:
        inputs = img_input

    # Create model.
    model = training.Model(inputs, x, name=model_name)
    return model
Example #28
0
def NASNet(
    input_shape=None,
    penultimate_filters=4032,
    num_blocks=6,
    stem_block_filters=96,
    skip_reduction=True,
    filter_multiplier=2,
    default_size=None,
):
    if backend.image_data_format() != 'channels_last':
        raise AttributeError(
            'The input data format "channels_last" is only supported.')

    if default_size is None:
        default_size = 331

    input_shape = imagenet_utils.obtain_input_shape(
        input_shape,
        default_size=default_size,
        min_size=32,
        data_format=backend.image_data_format(),
        require_flatten=True)

    img_input = layers.Input(shape=input_shape)

    if penultimate_filters % (24 * (filter_multiplier**2)) != 0:
        raise ValueError(
            'For NASNet-A models, the `penultimate_filters` must be a multiple '
            'of 24 * (`filter_multiplier` ** 2). Current value: %d' %
            penultimate_filters)

    channel_dim = -1
    filters = penultimate_filters // 24

    x = layers.Conv2D(stem_block_filters, (3, 3),
                      strides=(2, 2),
                      padding='valid',
                      use_bias=False,
                      name='stem_conv1',
                      kernel_initializer='he_normal')(img_input)

    x = layers.BatchNormalization(axis=channel_dim,
                                  momentum=0.9997,
                                  epsilon=1e-3,
                                  name='stem_bn1')(x)

    p = None
    x, p = _reduction_a_cell(x,
                             p,
                             filters // (filter_multiplier**2),
                             block_id='stem_1')
    x, p = _reduction_a_cell(x,
                             p,
                             filters // filter_multiplier,
                             block_id='stem_2')

    for i in range(num_blocks):
        x, p = _normal_a_cell(x, p, filters, block_id='%d' % (i))

    x, p0 = _reduction_a_cell(x,
                              p,
                              filters * filter_multiplier,
                              block_id='reduce_%d' % (num_blocks))

    p = p0 if not skip_reduction else p

    for i in range(num_blocks):
        x, p = _normal_a_cell(x,
                              p,
                              filters * filter_multiplier,
                              block_id='%d' % (num_blocks + i + 1))

    x, p0 = _reduction_a_cell(x,
                              p,
                              filters * filter_multiplier**2,
                              block_id='reduce_%d' % (2 * num_blocks))

    p = p0 if not skip_reduction else p

    for i in range(num_blocks):
        x, p = _normal_a_cell(x,
                              p,
                              filters * filter_multiplier**2,
                              block_id='%d' % (2 * num_blocks + i + 1))

    x = layers.Activation('relu')(x)

    x = layers.GlobalAveragePooling2D()(x)
    imagenet_utils.validate_activation('softmax', None)
    x = layers.Dense(NUM_CLASSES, activation='softmax', name='predictions')(x)

    model = training.Model(img_input, x, name='NASNet')

    return model