Exemplo n.º 1
0
def subsample(inputs, factor, scope=None):
    """Subsamples the input along the spatial dimensions.

    Args:
      inputs: A `Tensor` of size [batch, height_in, width_in, channels].
      factor: The subsampling factor.
      scope: Optional variable_scope.

    Returns:
      output: A `Tensor` of size [batch, height_out, width_out, channels] with the
        input, either intact (if factor == 1) or subsampled (if factor > 1).
    """
    if factor == 1:
        return inputs
    else:
        return layers.max_pool2d(inputs, [1, 1], stride=factor, scope=scope)
Exemplo n.º 2
0
def resnet_v2(inputs,
              blocks,
              num_classes=None,
              is_training=True,
              global_pool=True,
              output_stride=None,
              include_root_block=True,
              reuse=None,
              scope=None):
    """Generator for v2 (preactivation) ResNet models.

  This function generates a family of ResNet v2 models. See the resnet_v2_*()
  methods for specific model instantiations, obtained by selecting different
  block instantiations that produce ResNets of various depths.

  Training for image classification on Imagenet is usually done with [224, 224]
  inputs, resulting in [7, 7] feature maps at the output of the last ResNet
  block for the ResNets defined in [1] that have nominal stride equal to 32.
  However, for dense prediction tasks we advise that one uses inputs with
  spatial dimensions that are multiples of 32 plus 1, e.g., [321, 321]. In
  this case the feature maps at the ResNet output will have spatial shape
  [(height - 1) / output_stride + 1, (width - 1) / output_stride + 1]
  and corners exactly aligned with the input image corners, which greatly
  facilitates alignment of the features to the image. Using as input [225, 225]
  images results in [8, 8] feature maps at the output of the last ResNet block.

  For dense prediction tasks, the ResNet needs to run in fully-convolutional
  (FCN) mode and global_pool needs to be set to False. The ResNets in [1, 2] all
  have nominal stride equal to 32 and a good choice in FCN mode is to use
  output_stride=16 in order to increase the density of the computed features at
  small computational and memory overhead, cf. http://arxiv.org/abs/1606.00915.

  Args:
    inputs: A tensor of size [batch, height_in, width_in, channels].
    blocks: A list of length equal to the number of ResNet blocks. Each element
      is a resnet_utils.Block object describing the units in the block.
    num_classes: Number of predicted classes for classification tasks. If None
      we return the features before the logit layer.
    is_training: whether batch_norm layers are in training mode.
    global_pool: If True, we perform global average pooling before computing the
      logits. Set to True for image classification, False for dense prediction.
    output_stride: If None, then the output will be computed at the nominal
      network stride. If output_stride is not None, it specifies the requested
      ratio of input to output spatial resolution.
    include_root_block: If True, include the initial convolution followed by
      max-pooling, if False excludes it. If excluded, `inputs` should be the
      results of an activation-less convolution.
    reuse: whether or not the network and its variables should be reused. To be
      able to reuse 'scope' must be given.
    scope: Optional variable_scope.


  Returns:
    net: A rank-4 tensor of size [batch, height_out, width_out, channels_out].
      If global_pool is False, then height_out and width_out are reduced by a
      factor of output_stride compared to the respective height_in and width_in,
      else both height_out and width_out equal one. If num_classes is None, then
      net is the output of the last ResNet block, potentially after global
      average pooling. If num_classes is not None, net contains the pre-softmax
      activations.
    end_points: A dictionary from components of the network to the corresponding
      activation.

  Raises:
    ValueError: If the target output_stride is not valid.
  """
    with variable_scope.variable_scope(scope,
                                       'resnet_v2', [inputs],
                                       reuse=reuse) as sc:
        end_points_collection = sc.original_name_scope + '_end_points'
        with arg_scope(
            [layers_lib.conv2d, bottleneck, resnet_utils.stack_blocks_dense],
                outputs_collections=end_points_collection):
            with arg_scope([layers.batch_norm], is_training=is_training):
                net = inputs
                if include_root_block:
                    if output_stride is not None:
                        if output_stride % 4 != 0:
                            raise ValueError(
                                'The output_stride needs to be a multiple of 4.'
                            )
                        output_stride /= 4
                    # We do not include batch normalization or activation functions in
                    # conv1 because the first ResNet unit will perform these. Cf.
                    # Appendix of [2].
                    with arg_scope([layers_lib.conv2d],
                                   activation_fn=None,
                                   normalizer_fn=None):
                        net = resnet_utils.conv2d_same(net,
                                                       64,
                                                       7,
                                                       stride=2,
                                                       scope='conv1')
                    net = layers.max_pool2d(net, [3, 3],
                                            stride=2,
                                            scope='pool1')
                net = resnet_utils.stack_blocks_dense(net, blocks,
                                                      output_stride)
                # This is needed because the pre-activation variant does not have batch
                # normalization or activation functions in the residual unit output. See
                # Appendix of [2].
                net = layers.batch_norm(net,
                                        activation_fn=nn_ops.relu,
                                        scope='postnorm')
                if global_pool:
                    # Global average pooling.
                    net = math_ops.reduce_mean(net, [1, 2],
                                               name='pool5',
                                               keepdims=True)
                if num_classes is not None:
                    net = layers_lib.conv2d(net,
                                            num_classes, [1, 1],
                                            activation_fn=None,
                                            normalizer_fn=None,
                                            scope='logits')
                # Convert end_points_collection into a dictionary of end_points.
                end_points = utils.convert_collection_to_dict(
                    end_points_collection)
                if num_classes is not None:
                    end_points['predictions'] = layers.softmax(
                        net, scope='predictions')
                return net, end_points
Exemplo n.º 3
0
def vgg_a(inputs,
          num_classes=1000,
          is_training=True,
          dropout_keep_prob=0.5,
          spatial_squeeze=True,
          scope='vgg_a'):
    """Oxford Net VGG 11-Layers version A Example.

  Note: All the fully_connected layers have been transformed to conv2d layers.
        To use in classification mode, resize input to 224x224.

  Args:
    inputs: a tensor of size [batch_size, height, width, channels].
    num_classes: number of predicted classes.
    is_training: whether or not the model is being trained.
    dropout_keep_prob: the probability that activations are kept in the dropout
      layers during training.
    spatial_squeeze: whether or not should squeeze the spatial dimensions of the
      outputs. Useful to remove unnecessary dimensions for classification.
    scope: Optional scope for the variables.

  Returns:
    the last op containing the log predictions and end_points dict.
  """
    with variable_scope.variable_scope(scope, 'vgg_a', [inputs]) as sc:
        end_points_collection = sc.original_name_scope + '_end_points'
        # Collect outputs for conv2d, fully_connected and max_pool2d.
        with arg_scope([layers.conv2d, layers_lib.max_pool2d],
                       outputs_collections=end_points_collection):
            net = layers_lib.repeat(inputs,
                                    1,
                                    layers.conv2d,
                                    64, [3, 3],
                                    scope='conv1')
            net = layers_lib.max_pool2d(net, [2, 2], scope='pool1')
            net = layers_lib.repeat(net,
                                    1,
                                    layers.conv2d,
                                    128, [3, 3],
                                    scope='conv2')
            net = layers_lib.max_pool2d(net, [2, 2], scope='pool2')
            net = layers_lib.repeat(net,
                                    2,
                                    layers.conv2d,
                                    256, [3, 3],
                                    scope='conv3')
            net = layers_lib.max_pool2d(net, [2, 2], scope='pool3')
            net = layers_lib.repeat(net,
                                    2,
                                    layers.conv2d,
                                    512, [3, 3],
                                    scope='conv4')
            net = layers_lib.max_pool2d(net, [2, 2], scope='pool4')
            net = layers_lib.repeat(net,
                                    2,
                                    layers.conv2d,
                                    512, [3, 3],
                                    scope='conv5')
            net = layers_lib.max_pool2d(net, [2, 2], scope='pool5')
            # Use conv2d instead of fully_connected layers.
            net = layers.conv2d(net,
                                4096, [7, 7],
                                padding='VALID',
                                scope='fc6')
            net = layers_lib.dropout(net,
                                     dropout_keep_prob,
                                     is_training=is_training,
                                     scope='dropout6')
            net = layers.conv2d(net, 4096, [1, 1], scope='fc7')
            net = layers_lib.dropout(net,
                                     dropout_keep_prob,
                                     is_training=is_training,
                                     scope='dropout7')
            net = layers.conv2d(net,
                                num_classes, [1, 1],
                                activation_fn=None,
                                normalizer_fn=None,
                                scope='fc8')
            # Convert end_points_collection into a end_point dict.
            end_points = utils.convert_collection_to_dict(
                end_points_collection)
            if spatial_squeeze:
                net = array_ops.squeeze(net, [1, 2], name='fc8/squeezed')
                end_points[sc.name + '/fc8'] = net
            return net, end_points
Exemplo n.º 4
0
def inception_v1_base(inputs, final_endpoint='Mixed_5c', scope='InceptionV1'):
    """Defines the Inception V1 base architecture.

  This architecture is defined in:
    Going deeper with convolutions
    Christian Szegedy, Wei Liu, Yangqing Jia, Pierre Sermanet, Scott Reed,
    Dragomir Anguelov, Dumitru Erhan, Vincent Vanhoucke, Andrew Rabinovich.
    http://arxiv.org/pdf/1409.4842v1.pdf.

  Args:
    inputs: a tensor of size [batch_size, height, width, channels].
    final_endpoint: specifies the endpoint to construct the network up to. It
      can be one of ['Conv2d_1a_7x7', 'MaxPool_2a_3x3', 'Conv2d_2b_1x1',
      'Conv2d_2c_3x3', 'MaxPool_3a_3x3', 'Mixed_3b', 'Mixed_3c',
      'MaxPool_4a_3x3', 'Mixed_4b', 'Mixed_4c', 'Mixed_4d', 'Mixed_4e',
      'Mixed_4f', 'MaxPool_5a_2x2', 'Mixed_5b', 'Mixed_5c']
    scope: Optional variable_scope.

  Returns:
    A dictionary from components of the network to the corresponding activation.

  Raises:
    ValueError: if final_endpoint is not set to one of the predefined values.
  """
    end_points = {}
    with variable_scope.variable_scope(scope, 'InceptionV1', [inputs]):
        with arg_scope([layers.conv2d, layers_lib.fully_connected],
                       weights_initializer=trunc_normal(0.01)):
            with arg_scope([layers.conv2d, layers_lib.max_pool2d],
                           stride=1,
                           padding='SAME'):
                end_point = 'Conv2d_1a_7x7'
                net = layers.conv2d(inputs,
                                    64, [7, 7],
                                    stride=2,
                                    scope=end_point)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points
                end_point = 'MaxPool_2a_3x3'
                net = layers_lib.max_pool2d(net, [3, 3],
                                            stride=2,
                                            scope=end_point)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points
                end_point = 'Conv2d_2b_1x1'
                net = layers.conv2d(net, 64, [1, 1], scope=end_point)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points
                end_point = 'Conv2d_2c_3x3'
                net = layers.conv2d(net, 192, [3, 3], scope=end_point)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points
                end_point = 'MaxPool_3a_3x3'
                net = layers_lib.max_pool2d(net, [3, 3],
                                            stride=2,
                                            scope=end_point)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_3b'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 64, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 96, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 128, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 16, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 32, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 32, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_3c'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 128, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 128, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 192, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 32, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 96, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 64, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'MaxPool_4a_3x3'
                net = layers_lib.max_pool2d(net, [3, 3],
                                            stride=2,
                                            scope=end_point)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_4b'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 192, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 96, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 208, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 16, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 48, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 64, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_4c'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 160, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 112, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 224, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 24, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 64, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 64, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_4d'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 128, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 128, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 256, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 24, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 64, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 64, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_4e'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 112, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 144, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 288, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 32, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 64, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 64, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_4f'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 256, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 160, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 320, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 32, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 128, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 128, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'MaxPool_5a_2x2'
                net = layers_lib.max_pool2d(net, [2, 2],
                                            stride=2,
                                            scope=end_point)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_5b'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 256, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 160, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 320, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 32, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 128, [3, 3],
                                                 scope='Conv2d_0a_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 128, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points

                end_point = 'Mixed_5c'
                with variable_scope.variable_scope(end_point):
                    with variable_scope.variable_scope('Branch_0'):
                        branch_0 = layers.conv2d(net,
                                                 384, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                    with variable_scope.variable_scope('Branch_1'):
                        branch_1 = layers.conv2d(net,
                                                 192, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_1 = layers.conv2d(branch_1,
                                                 384, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_2'):
                        branch_2 = layers.conv2d(net,
                                                 48, [1, 1],
                                                 scope='Conv2d_0a_1x1')
                        branch_2 = layers.conv2d(branch_2,
                                                 128, [3, 3],
                                                 scope='Conv2d_0b_3x3')
                    with variable_scope.variable_scope('Branch_3'):
                        branch_3 = layers_lib.max_pool2d(
                            net, [3, 3], scope='MaxPool_0a_3x3')
                        branch_3 = layers.conv2d(branch_3,
                                                 128, [1, 1],
                                                 scope='Conv2d_0b_1x1')
                    net = array_ops.concat(
                        [branch_0, branch_1, branch_2, branch_3], 3)
                end_points[end_point] = net
                if final_endpoint == end_point:
                    return net, end_points
        raise ValueError('Unknown final endpoint %s' % final_endpoint)
Exemplo n.º 5
0
def alexnet_v2(inputs,
               num_classes=1000,
               is_training=True,
               dropout_keep_prob=0.5,
               spatial_squeeze=True,
               scope='alexnet_v2'):
    """AlexNet version 2.

  Described in: http://arxiv.org/pdf/1404.5997v2.pdf
  Parameters from:
  github.com/akrizhevsky/cuda-convnet2/blob/master/layers/
  layers-imagenet-1gpu.cfg

  Note: All the fully_connected layers have been transformed to conv2d layers.
        To use in classification mode, resize input to 224x224. To use in fully
        convolutional mode, set spatial_squeeze to false.
        The LRN layers have been removed and change the initializers from
        random_normal_initializer to xavier_initializer.

  Args:
    inputs: a tensor of size [batch_size, height, width, channels].
    num_classes: number of predicted classes.
    is_training: whether or not the model is being trained.
    dropout_keep_prob: the probability that activations are kept in the dropout
      layers during training.
    spatial_squeeze: whether or not should squeeze the spatial dimensions of the
      outputs. Useful to remove unnecessary dimensions for classification.
    scope: Optional scope for the variables.

  Returns:
    the last op containing the log predictions and end_points dict.
  """
    with variable_scope.variable_scope(scope, 'alexnet_v2', [inputs]) as sc:
        end_points_collection = sc.original_name_scope + '_end_points'
        # Collect outputs for conv2d, fully_connected and max_pool2d.
        with arg_scope(
            [layers.conv2d, layers_lib.fully_connected, layers_lib.max_pool2d],
                outputs_collections=[end_points_collection]):
            net = layers.conv2d(inputs,
                                64, [11, 11],
                                4,
                                padding='VALID',
                                scope='conv1')
            net = layers_lib.max_pool2d(net, [3, 3], 2, scope='pool1')
            net = layers.conv2d(net, 192, [5, 5], scope='conv2')
            net = layers_lib.max_pool2d(net, [3, 3], 2, scope='pool2')
            net = layers.conv2d(net, 384, [3, 3], scope='conv3')
            net = layers.conv2d(net, 384, [3, 3], scope='conv4')
            net = layers.conv2d(net, 256, [3, 3], scope='conv5')
            net = layers_lib.max_pool2d(net, [3, 3], 2, scope='pool5')

            # Use conv2d instead of fully_connected layers.
            with arg_scope(
                [layers.conv2d],
                    weights_initializer=trunc_normal(0.005),
                    biases_initializer=init_ops.constant_initializer(0.1)):
                net = layers.conv2d(net,
                                    4096, [5, 5],
                                    padding='VALID',
                                    scope='fc6')
                net = layers_lib.dropout(net,
                                         dropout_keep_prob,
                                         is_training=is_training,
                                         scope='dropout6')
                net = layers.conv2d(net, 4096, [1, 1], scope='fc7')
                net = layers_lib.dropout(net,
                                         dropout_keep_prob,
                                         is_training=is_training,
                                         scope='dropout7')
                net = layers.conv2d(
                    net,
                    num_classes, [1, 1],
                    activation_fn=None,
                    normalizer_fn=None,
                    biases_initializer=init_ops.zeros_initializer(),
                    scope='fc8')

            # Convert end_points_collection into a end_point dict.
            end_points = utils.convert_collection_to_dict(
                end_points_collection)
            if spatial_squeeze:
                net = array_ops.squeeze(net, [1, 2], name='fc8/squeezed')
                end_points[sc.name + '/fc8'] = net
            return net, end_points
Exemplo n.º 6
0
def overfeat(inputs,
             num_classes=1000,
             is_training=True,
             dropout_keep_prob=0.5,
             spatial_squeeze=True,
             scope='overfeat'):
  """Contains the model definition for the OverFeat network.

  The definition for the network was obtained from:
    OverFeat: Integrated Recognition, Localization and Detection using
    Convolutional Networks
    Pierre Sermanet, David Eigen, Xiang Zhang, Michael Mathieu, Rob Fergus and
    Yann LeCun, 2014
    http://arxiv.org/abs/1312.6229

  Note: All the fully_connected layers have been transformed to conv2d layers.
        To use in classification mode, resize input to 231x231. To use in fully
        convolutional mode, set spatial_squeeze to false.

  Args:
    inputs: a tensor of size [batch_size, height, width, channels].
    num_classes: number of predicted classes.
    is_training: whether or not the model is being trained.
    dropout_keep_prob: the probability that activations are kept in the dropout
      layers during training.
    spatial_squeeze: whether or not should squeeze the spatial dimensions of the
      outputs. Useful to remove unnecessary dimensions for classification.
    scope: Optional scope for the variables.

  Returns:
    the last op containing the log predictions and end_points dict.

  """
  with variable_scope.variable_scope(scope, 'overfeat', [inputs]) as sc:
    end_points_collection = sc.name + '_end_points'
    # Collect outputs for conv2d, fully_connected and max_pool2d
    with arg_scope(
        [layers.conv2d, layers_lib.fully_connected, layers_lib.max_pool2d],
        outputs_collections=end_points_collection):
      net = layers.conv2d(
          inputs, 64, [11, 11], 4, padding='VALID', scope='conv1')
      net = layers_lib.max_pool2d(net, [2, 2], scope='pool1')
      net = layers.conv2d(net, 256, [5, 5], padding='VALID', scope='conv2')
      net = layers_lib.max_pool2d(net, [2, 2], scope='pool2')
      net = layers.conv2d(net, 512, [3, 3], scope='conv3')
      net = layers.conv2d(net, 1024, [3, 3], scope='conv4')
      net = layers.conv2d(net, 1024, [3, 3], scope='conv5')
      net = layers_lib.max_pool2d(net, [2, 2], scope='pool5')
      with arg_scope(
          [layers.conv2d],
          weights_initializer=trunc_normal(0.005),
          biases_initializer=init_ops.constant_initializer(0.1)):
        # Use conv2d instead of fully_connected layers.
        net = layers.conv2d(net, 3072, [6, 6], padding='VALID', scope='fc6')
        net = layers_lib.dropout(
            net, dropout_keep_prob, is_training=is_training, scope='dropout6')
        net = layers.conv2d(net, 4096, [1, 1], scope='fc7')
        net = layers_lib.dropout(
            net, dropout_keep_prob, is_training=is_training, scope='dropout7')
        net = layers.conv2d(
            net,
            num_classes, [1, 1],
            activation_fn=None,
            normalizer_fn=None,
            biases_initializer=init_ops.zeros_initializer(),
            scope='fc8')
      # Convert end_points_collection into a end_point dict.
      end_points = utils.convert_collection_to_dict(end_points_collection)
      if spatial_squeeze:
        net = array_ops.squeeze(net, [1, 2], name='fc8/squeezed')
        end_points[sc.name + '/fc8'] = net
      return net, end_points