def resnet50(num_classes, dtype='float32', batch_size=None):
"""Instantiates the ResNet50 architecture.
Args:
num_classes: `int` number of classes for image classification.
dtype: dtype to use float32 or float16 are most common.
batch_size: Size of the batches for each step.
Returns:
A Keras model instance.
"""
input_shape = (32, 64, 3)
img_input = layers.Input(shape=input_shape,
dtype=dtype,
batch_size=batch_size)
if backend.image_data_format() == 'channels_first':
x = layers.Lambda(
lambda x: backend.permute_dimensions(x, (0, 3, 1, 2)),
name='transpose')(img_input)
bn_axis = 1
else: # channels_last
x = img_input
bn_axis = 3
# x = layers.ZeroPadding2D(padding=(1, 1), name='conv1_pad')(x)
x = layers.Conv2D(16, (7, 7),
strides=(2, 2),
padding='same',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name='conv1')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name='bn_conv1')(x)
x = layers.Activation('relu')(x)
x = layers.MaxPooling2D((2, 4), strides=(2, 4), padding='same')(x)
x = conv_block(x, 3, [16, 16, 64], stage=2, block='a', strides=(1, 1))
x = identity_block(x, 3, [16, 16, 64], stage=2, block='b')
x = identity_block(x, 3, [16, 16, 64], stage=2, block='c')
x = conv_block(x, 3, [32, 32, 128], stage=3, block='a')
x = identity_block(x, 3, [32, 32, 128], stage=3, block='b')
x = identity_block(x, 3, [32, 32, 128], stage=3, block='c')
x = identity_block(x, 3, [32, 32, 128], stage=3, block='d')
x = conv_block(x, 3, [64, 64, 256], stage=4, block='a')
x = identity_block(x, 3, [64, 64, 256], stage=4, block='b')
x = identity_block(x, 3, [64, 64, 256], stage=4, block='c')
x = identity_block(x, 3, [64, 64, 256], stage=4, block='d')
x = identity_block(x, 3, [64, 64, 256], stage=4, block='e')
x = identity_block(x, 3, [64, 64, 256], stage=4, block='f')
x = conv_block(x, 3, [128, 128, 512], stage=5, block='a')
x = identity_block(x, 3, [128, 128, 512], stage=5, block='b')
x = identity_block(x, 3, [128, 128, 512], stage=5, block='c')
rm_axes = [1, 2
] if backend.image_data_format() == 'channels_last' else [2, 3]
x = layers.Lambda(lambda x: backend.mean(x, rm_axes),
name='reduce_mean')(x)
x = layers.Dense(num_classes,
kernel_initializer=initializers.RandomNormal(stddev=0.01),
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
bias_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name='fc1000')(x)
# TODO(reedwm): Remove manual casts once mixed precision can be enabled with a
# single line of code.
x = backend.cast(x, 'float32')
x = layers.Activation('softmax')(x)
# Create model.
return models.Model(img_input, x, name='resnet50')
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.
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:
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 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=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(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
convolution_14_output = convolution_14(convolution_layer_3_output)
convolution_15_output = convolution_15(convolution_layer_3_output)
convolution_16_output = convolution_16(convolution_layer_3_output)
convolution_layer_4_output = concatenate([
convolution_13_output, convolution_14_output, convolution_15_output,
convolution_16_output
])
convolution_17 = layers.Conv1D(len(dictionary),
3,
padding="same",
activation=None)
convolution_17_output = convolution_17(convolution_layer_4_output)
activation_1 = layers.Activation("softmax")
activation_1_output = activation_1(convolution_17_output)
decoder = models.Model(inputs=[input_2], outputs=[activation_1_output])
decoder.summary()
input_3 = layers.Input(shape=(word_length, len(dictionary)))
input_4 = layers.Input(shape=(window_size * 2, word_length, len(dictionary)))
encoder_output_1 = encoder(input_3)
repeat_vector_1 = layers.RepeatVector(window_size * 2)
repeat_vector_1_output = repeat_vector_1(encoder_output_1)
timedistributed_encoder_1 = layers.TimeDistributed(encoder)
def DenseNet(blocks,
classes,
filters,
dropout_rate,
include_top=True,
weights=None,
input_tensor=None,
input_shape=None,
pooling=None,
classifier_activation=None):
# Determine proper input shape
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 = layers.ZeroPadding2D(padding=((3, 3), (3, 3)))(x)
x = layers.Conv2D(2 * filters,
3,
strides=2,
padding='same',
name='conv1/conv')(img_input)
# 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(pool_size=(3, 3), strides=2, name='pool1')(x)
# x = dense_block(x,
# blocks=6,
# filters=filters,
# dropout_rate=dropout_rate,
# name='dense_1')
# x = transition_block(x, dropout_rate=dropout_rate, name='trans_2')
# x = dense_block(x,
# blocks=12,
# filters=filters,
# dropout_rate=dropout_rate,
# name='dense_2')
# x = transition_block(x, dropout_rate=dropout_rate, name='trans_3')
# x = dense_block(x,
# blocks=24,
# filters=filters,
# dropout_rate=dropout_rate,
# name='dense_3')
# x = transition_block(x, dropout_rate=dropout_rate, name='trans_4')
# x = dense_block(x,
# blocks=16,
# filters=filters,
# dropout_rate=dropout_rate,
# name='dense_4')
for i in range(blocks):
x = dense_block(x,
blocks=6,
filters=filters,
dropout_rate=dropout_rate,
name='dense_' + str(i))
x = transition_block(x,
dropout_rate=dropout_rate,
name='trans_' + str(i))
x = dense_block(x,
blocks=12,
filters=filters,
dropout_rate=dropout_rate,
name='dense_final')
x = layers.BatchNormalization()(x)
x = layers.Activation('relu', name='relu')(x)
if include_top:
x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
x = layers.Flatten()(x)
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='NET.model')
return model
def identity_block(input_tensor,
kernel_size,
filters,
stage,
block,
use_l2_regularizer=True):
"""The identity block is the block that has no conv layer at shortcut.
Args:
input_tensor: input tensor
kernel_size: default 3, the kernel size of middle conv layer at main path
filters: list of integers, the filters of 3 conv layer at main path
stage: integer, current stage label, used for generating layer names
block: 'a','b'..., current block label, used for generating layer names
use_l2_regularizer: whether to use L2 regularizer on Conv layer.
Returns:
Output tensor for the block.
"""
filters1, filters2, filters3 = filters
if backend.image_data_format() == 'channels_last':
bn_axis = 3
else:
bn_axis = 1
conv_name_base = 'res' + str(stage) + block + '_branch'
bn_name_base = 'bn' + str(stage) + block + '_branch'
x = layers.Conv2D(
filters1, (1, 1),
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=_gen_l2_regularizer(use_l2_regularizer),
name=conv_name_base + '2a')(input_tensor)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2a')(x)
x = layers.Activation('relu')(x)
x = layers.Conv2D(
filters2,
kernel_size,
padding='same',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=_gen_l2_regularizer(use_l2_regularizer),
name=conv_name_base + '2b')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2b')(x)
x = layers.Activation('relu')(x)
x = layers.Conv2D(
filters3, (1, 1),
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=_gen_l2_regularizer(use_l2_regularizer),
name=conv_name_base + '2c')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2c')(x)
x = layers.add([x, input_tensor])
x = layers.Activation('relu')(x)
return x
def resnet50(num_classes, input_shape):
img_input = layers.Input(shape=input_shape)
if backend.image_data_format() == 'channels_first':
x = layers.Lambda(
lambda x: backend.permute_dimensions(x, (0, 3, 1, 2)),
name='transpose')(img_input)
bn_axis = 1
else: # channels_last
x = img_input
bn_axis = 3
# Conv1 (7x7,64,stride=2)
#x = layers.ZeroPadding2D(padding=(3, 3))(x)
x = layers.Conv2D(64, (7, 7),
strides=(2, 2),
padding='valid',
use_bias=False,
kernel_initializer='he_normal')(x)
x = layers.BatchNormalization()(x)
x = layers.Activation('relu')(x)
x = layers.ZeroPadding2D(padding=(1, 1))(x)
# 3x3 max pool,stride=2
x = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)
# Conv2_x
# 1×1, 64
# 3×3, 64
# 1×1, 256
x = conv_block(x, 3, [64, 64, 256], strides=(1, 1))
########x = identity_block(x, 3, [64, 64, 256])
x = identity_block(x, 3, [64, 64, 256])
# Conv3_x
#
# 1×1, 128
# 3×3, 128
# 1×1, 512
x = conv_block(x, 3, [128, 128, 512])
######## x = identity_block(x, 3, [128, 128, 512])
########x = identity_block(x, 3, [128, 128, 512])
x = identity_block(x, 3, [128, 128, 512])
# Conv4_x
# 1×1, 256
# 3×3, 256
# 1×1, 1024
x = conv_block(x, 3, [256, 256, 1024])
x = identity_block(x, 3, [256, 256, 1024])
########x = identity_block(x, 3, [256, 256, 1024])
########x = identity_block(x, 3, [256, 256, 1024])
x = identity_block(x, 3, [256, 256, 1024])
x = identity_block(x, 3, [256, 256, 1024])
# 1×1, 512
# 3×3, 512
# 1×1, 2048
x = conv_block(x, 3, [512, 512, 2048])
########x = identity_block(x, 3, [512, 512, 2048])
x = identity_block(x, 3, [512, 512, 2048])
# average pool, 1000-d fc, softmax
x = layers.GlobalAveragePooling2D()(x)
x = layers.Dense(2, activation='softmax')(x)
# Create model.
return models.Model(img_input, x, name='resnet50')
def resnet101(self, num_classes, dtype='float32', batch_size=None):
# TODO(tfboyd): add training argument, just lik resnet56.
"""Instantiates the ResNet50 architecture.
Args:
num_classes: `int` number of classes for image classification.
Returns:
A Keras model instance.
"""
input_shape = (384, 384, 3)
img_input = layers.Input(shape=input_shape,
dtype=dtype,
batch_size=batch_size)
if backend.image_data_format() == 'channels_first':
x = layers.Lambda(
lambda x: backend.permute_dimensions(x, (0, 3, 1, 2)),
name='transpose')(img_input)
bn_axis = 1
else: # channels_last
x = img_input
bn_axis = 3
x = layers.ZeroPadding2D(padding=(3, 3), name='conv1_pad')(x)
x = layers.Conv2D(64, (7, 7),
strides=(2, 2),
padding='valid',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(
self.L2_WEIGHT_DECAY),
name='conv1')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=self.BATCH_NORM_DECAY,
epsilon=self.BATCH_NORM_EPSILON,
name='bn_conv1')(x)
x = layers.Activation('relu')(x)
x = layers.MaxPooling2D((3, 3), strides=(2, 2), padding='same')(x)
x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1))
x = identity_block(x, 3, [64, 64, 256], stage=2, block='b')
x = identity_block(x, 3, [64, 64, 256], stage=2, block='c')
x = conv_block(x, 3, [128, 128, 512], stage=3, block='a')
x = identity_block(x, 3, [128, 128, 512], stage=3, block='b')
x = identity_block(x, 3, [128, 128, 512], stage=3, block='c')
x = identity_block(x, 3, [128, 128, 512], stage=3, block='d')
x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='g')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='h')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='i')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='j')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='k')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='l')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='m')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='n')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='o')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='p')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='q')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='r')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='s')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='t')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='u')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='v')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='w')
x = conv_block(x, 3, [512, 512, 2048], stage=5, block='a')
x = identity_block(x, 3, [512, 512, 2048], stage=5, block='b')
x = identity_block(x, 3, [512, 512, 2048], stage=5, block='c')
rm_axes = [
1, 2
] if backend.image_data_format() == 'channels_last' else [2, 3]
x = layers.Lambda(lambda x: backend.mean(x, rm_axes),
name='reduce_mean')(x)
x = layers.Dense(
num_classes,
kernel_regularizer=regularizers.l2(self.L2_WEIGHT_DECAY),
bias_regularizer=regularizers.l2(self.L2_WEIGHT_DECAY),
name='fc1000')(x)
# TODO(reedwm): Remove manual casts once mixed precision can be enabled with a
# single line of code.
x = backend.cast(x, 'float32')
x = layers.Activation('softmax')(x)
# Create model.
return models.Model(img_input, x, name='resnet50')
def conv_block(input_tensor, kernel_size, filters, stage, block, strides=2):
"""A block that has a conv layer at shortcut.
Note that from stage 3,
the second conv layer at main path is with strides=(2, 2)
And the shortcut should have strides=(2, 2) as well
Args:
input_tensor: input tensor
kernel_size: default 3, the kernel size of middle conv layer at main path
filters: integer, filters of the bottleneck layer.
stage: integer, current stage label, used for generating layer names
block: 'a','b'..., current block label, used for generating layer names
strides: Strides for the second conv layer in the block.
Returns:
Output tensor for the block.
"""
if backend.image_data_format() == 'channels_last':
bn_axis = -1
else:
bn_axis = 1
conv_name_base = 'res' + str(stage) + block + '_branch'
bn_name_base = 'bn' + str(stage) + block + '_branch'
x = layers.Conv2D(filters=filters,
kernel_size=1,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2a')(input_tensor)
x = layers.BatchNormalization(axis=bn_axis, name=bn_name_base + '2a')(x)
x = layers.Activation('relu')(x)
x = layers.Conv2D(filters=filters,
kernel_size=kernel_size,
strides=strides,
padding='same',
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2b')(x)
x = layers.BatchNormalization(axis=bn_axis, name=bn_name_base + '2b')(x)
x = layers.Activation('relu')(x)
x = layers.Conv2D(filters=4 * filters,
kernel_size=1,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2c')(x)
x = layers.BatchNormalization(axis=bn_axis, name=bn_name_base + '2c')(x)
shortcut = layers.Conv2D(
filters=4 * filters,
kernel_size=1,
strides=strides,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '1')(input_tensor)
shortcut = layers.BatchNormalization(axis=bn_axis,
name=bn_name_base + '1')(shortcut)
x = layers.add([x, shortcut])
x = layers.Activation('relu')(x)
return x
def resnet(num_blocks, classes=10, training=None):
"""Instantiates the ResNet architecture.
Arguments:
num_blocks: integer, the number of conv/identity blocks in each block.
The ResNet contains 3 blocks with each block containing one conv block
followed by (layers_per_block - 1) number of idenity blocks. Each
conv/idenity block has 2 convolutional layers. With the input
convolutional layer and the pooling layer towards the end, this brings
the total size of the network to (6*num_blocks + 2)
classes: optional number of classes to classify images into
training: Only used if training keras model with Estimator. In other
scenarios it is handled automatically.
Returns:
A Keras model instance.
"""
input_shape = (32, 32, 3)
img_input = layers.Input(shape=input_shape)
if backend.image_data_format() == 'channels_first':
x = layers.Lambda(
lambda x: backend.permute_dimensions(x, (0, 3, 1, 2)),
name='transpose')(img_input)
bn_axis = 1
else: # channel_last
x = img_input
bn_axis = 3
x = layers.ZeroPadding2D(padding=(1, 1), name='conv1_pad')(x)
x = layers.Conv2D(16, (3, 3),
strides=(1, 1),
padding='valid',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name='conv1')(x)
x = layers.BatchNormalization(
axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name='bn_conv1',
)(x, training=training)
x = layers.Activation('relu')(x)
x = resnet_block(x,
size=num_blocks,
kernel_size=3,
filters=[16, 16],
stage=2,
conv_strides=(1, 1),
training=training)
x = resnet_block(x,
size=num_blocks,
kernel_size=3,
filters=[32, 32],
stage=3,
conv_strides=(2, 2),
training=training)
x = resnet_block(x,
size=num_blocks,
kernel_size=3,
filters=[64, 64],
stage=4,
conv_strides=(2, 2),
training=training)
rm_axes = [1, 2
] if backend.image_data_format() == 'channels_last' else [2, 3]
x = layers.Lambda(lambda x: backend.mean(x, rm_axes),
name='reduce_mean')(x)
x = layers.Dense(classes,
activation='softmax',
kernel_initializer=initializers.RandomNormal(stddev=0.01),
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
bias_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name='fc10')(x)
inputs = img_input
# Create model.
model = tf.keras.models.Model(inputs, x, name='resnet56')
return model
def EfficientNet(input_shape,
block_args_list,
global_params,
include_top=True,
pooling=None):
batch_norm_momentum = global_params.batch_norm_momentum
batch_norm_epsilon = global_params.batch_norm_epsilon
if global_params.data_format == 'channels_first':
channel_axis = 1
else:
channel_axis = -1
# Stem part
inputs = KL.Input(shape=input_shape)
x = inputs
x = KL.Conv2D(filters=round_filters(32, global_params),
kernel_size=[3, 3],
strides=[2, 2],
kernel_initializer=ConvKernalInitializer(),
padding='same',
use_bias=False)(x)
x = KL.BatchNormalization(axis=channel_axis,
momentum=batch_norm_momentum,
epsilon=batch_norm_epsilon)(x)
x = Swish()(x)
# Blocks part
block_idx = 1
n_blocks = sum([block_args.num_repeat for block_args in block_args_list])
drop_rate = global_params.drop_connect_rate or 0
drop_rate_dx = drop_rate / n_blocks
for block_args in block_args_list:
assert block_args.num_repeat > 0
# Update block input and output filters based on depth multiplier.
block_args = block_args._replace(
input_filters=round_filters(block_args.input_filters,
global_params),
output_filters=round_filters(block_args.output_filters,
global_params),
num_repeat=round_repeats(block_args.num_repeat, global_params))
# The first block needs to take care of stride and filter size increase.
x = MBConvBlock(block_args,
global_params,
drop_connect_rate=drop_rate_dx * block_idx)(x)
block_idx += 1
if block_args.num_repeat > 1:
block_args = block_args._replace(
input_filters=block_args.output_filters, strides=[1, 1])
for _ in xrange(block_args.num_repeat - 1):
x = MBConvBlock(block_args,
global_params,
drop_connect_rate=drop_rate_dx * block_idx)(x)
block_idx += 1
# Head part
x = KL.Conv2D(filters=round_filters(1280, global_params),
kernel_size=[1, 1],
strides=[1, 1],
kernel_initializer=ConvKernalInitializer(),
padding='same',
use_bias=False)(x)
x = KL.BatchNormalization(axis=channel_axis,
momentum=batch_norm_momentum,
epsilon=batch_norm_epsilon)(x)
x = Swish()(x)
if include_top:
x = KL.GlobalAveragePooling2D(data_format=global_params.data_format)(x)
if global_params.dropout_rate > 0:
x = KL.Dropout(global_params.dropout_rate)(x)
x = KL.Dense(global_params.num_classes,
kernel_initializer=DenseKernalInitializer())(x)
x = KL.Activation('softmax')(x)
else:
if pooling == 'avg':
x = KL.GlobalAveragePooling2D(
data_format=global_params.data_format)(x)
elif pooling == 'max':
x = KL.GlobalMaxPooling2D(data_format=global_params.data_format)(x)
outputs = x
model = KM.Model(inputs, outputs)
return model
def conv_block(input_tensor, num_filters):
encoder = layers.Conv2D(num_filters, (3, 3), padding='same')(input_tensor)
encoder = layers.BatchNormalization()(encoder)
encoder = layers.Activation('relu')(encoder)
return encoder
def small_densenet(self,
img_input_shape=(64, 64, 3),
blocks=[6, 12, 24, 16],
weight_decay=1e-4,
kernel_initializer='he_normal',
init_filters=None,
reduction=None,
growth_rate=None,
init_stride=None):
img_input = Input(shape=(img_input_shape))
# x = layers.Conv2D(init_filters, 3, strides=1, use_bias=False,
# kernel_initializer = kernel_initializer,
# kernel_regularizer = l2(weight_decay),
# name='conv1/conv')(img_input)
x = layers.ZeroPadding2D(padding=((3, 3), (3, 3)))(img_input)
x = layers.Conv2D(init_filters,
3,
strides=init_stride,
use_bias=False,
kernel_initializer=kernel_initializer,
kernel_regularizer=l2(weight_decay),
name='conv1/conv')(x)
x = layers.BatchNormalization(axis=3,
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.AveragePooling2D(3, strides=2, name='pool1')(x)
for i, block in enumerate(blocks):
scope_num_str = str(i + 2)
x = self.dense_block(x,
block,
name='conv' + scope_num_str,
growth_rate=growth_rate,
weight_decay=weight_decay,
kernel_initializer=kernel_initializer)
if i != len(blocks) - 1:
x = self.transition_block(
x,
reduction,
name='pool' + scope_num_str,
weight_decay=weight_decay,
kernel_initializer=kernel_initializer)
x = layers.BatchNormalization(axis=3, epsilon=1.001e-5, name='bn')(x)
x = layers.Activation('relu', name='relu')(x)
x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
# x = Lambda(lambda x: x, name = 'densenet_features')(x)
# x = self.full_connect_layer(x, self.hidden_dim, weight_decay = weight_decay, kernel_initializer = kernel_initializer)
x = layers.Dense(
self.cat_max,
activation='softmax',
kernel_initializer=kernel_initializer,
# kernel_regularizer = l2(weight_decay),
name='fc')(x)
model = Model(img_input, x)
# print (model.summary())
model.compile(optimizer=Adam(lr=self.lr),
loss='categorical_crossentropy',
metrics=['categorical_accuracy'])
return model
def resnet_v1(input_shape, depth, num_classes=2):
"""ResNet Version 1 Model builder [a]
Stacks of 2 x (3 x 3) Conv2D-BN-ReLU
Last ReLU is after the shortcut connection.
At the beginning of each stage, the feature map size is halved (downsampled)
by a convolutional layer with strides=2, while the number of filters is
doubled. Within each stage, the layers have the same number filters and the
same number of filters.
Features maps sizes:
stage 0: 32x32, 16
stage 1: 16x16, 32
stage 2: 8x8, 64
The Number of parameters is approx the same as Table 6 of [a]:
ResNet20 0.27M
ResNet32 0.46M
ResNet44 0.66M
ResNet56 0.85M
ResNet110 1.7M
# Arguments
input_shape (tensor): shape of input image tensor
depth (int): number of core convolutional layers
num_classes (int): number of classes (CIFAR10 has 10)
# Returns
model (Model): Keras model instance
"""
if (depth-2)%6 != 0:
raise ValueError('depth should be 6n+2')
# Start model definition.
num_filters = 32
num_res_blocks = int((depth-2)/6)
inputs = tf.keras.Input(shape=input_shape)
x = resnet_layer(inputs, num_filters)
# Instantiate teh stack of residual units
for stack in range(3):
for res_block in range(num_res_blocks):
strides = 1
if stack > 0 and res_block == 0: # first layer but not first stack
strides = 2 # downsample
y = resnet_layer(x, num_filters, strides=strides)
y = resnet_layer(y, num_filters, activation=None)
if stack > 0 and res_block == 0: # first layer but not first stack
# linear projection residual shortcut connection to match
# change dims
x = resnet_layer(x, num_filters, kernel_size=1, strides=strides,
activation=None, batch_normalization=False)
x = layers.add([x, y])
x = layers.Activation('relu')(x)
num_filters *= 2
# Add classifier on top.
# v1 does not use BN after last shortcut connection-ReLU
ax = layers.GlobalAveragePooling2D()(x)
#x = layers.AveragePooling2D()(x)
ax = layers.Dense(num_filters//8, activation='relu')(ax)
ax = layers.Dense(num_filters//2, activation='softmax')(ax)
ax = layers.Reshape((1,1,num_filters//2))(ax)
ax = layers.Multiply()([ax, x])
y = layers.Flatten()(ax)
outputs = layers.Dense(num_classes, activation='softmax',
kernel_initializer='he_normal')(y)
# Instantiate model
model = models.Model(inputs=inputs, outputs=outputs)
return model
def __init__(self, num_classes=10, dtype="float32", batch_size=None):
super(CustomModel, self).__init__(name="resnet50")
if backend.image_data_format() == "channels_first":
self._lambda = layers.Lambda(
lambda x: backend.permute_dimensions(x, (0, 3, 1, 2)),
name="transpose",
)
bn_axis = 1
data_format = "channels_first"
else:
bn_axis = 3
data_format = "channels_last"
self._padding = layers.ZeroPadding2D(padding=(3, 3),
data_format=data_format,
name="zero_pad")
self._conv2d_1 = layers.Conv2D(
64,
(7, 7),
strides=(2, 2),
padding="valid",
use_bias=False,
kernel_initializer="he_normal",
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name="conv1",
)
self._bn_1 = layers.BatchNormalization(
axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name="bn_conv1",
)
self._activation_1 = layers.Activation("relu")
self._maxpooling2d = layers.MaxPooling2D((3, 3),
strides=(2, 2),
padding="same")
self._conv_block_1 = ConvBlock(3, [64, 64, 256],
stage=2,
block="a",
strides=(1, 1))
self._identity_block_1 = IdentityBlock(3, [64, 64, 256],
stage=2,
block="b")
self._identity_block_2 = IdentityBlock(3, [64, 64, 256],
stage=2,
block="c")
self._conv_block_2 = ConvBlock(3, [128, 128, 512], stage=3, block="a")
self._identity_block_3 = IdentityBlock(3, [128, 128, 512],
stage=3,
block="b")
self._identity_block_4 = IdentityBlock(3, [128, 128, 512],
stage=3,
block="c")
self._identity_block_5 = IdentityBlock(3, [128, 128, 512],
stage=3,
block="d")
self._conv_block_3 = ConvBlock(3, [256, 256, 1024], stage=4, block="a")
self._identity_block_6 = IdentityBlock(3, [256, 256, 1024],
stage=4,
block="b")
self._identity_block_7 = IdentityBlock(3, [256, 256, 1024],
stage=4,
block="c")
self._identity_block_8 = IdentityBlock(3, [256, 256, 1024],
stage=4,
block="d")
self._identity_block_9 = IdentityBlock(3, [256, 256, 1024],
stage=4,
block="e")
self._identity_block_10 = IdentityBlock(3, [256, 256, 1024],
stage=4,
block="f")
self._conv_block_4 = ConvBlock(3, [512, 512, 2048], stage=5, block="a")
self._identity_block_11 = IdentityBlock(3, [512, 512, 2048],
stage=5,
block="b")
self._identity_block_12 = IdentityBlock(3, [512, 512, 2048],
stage=5,
block="c")
rm_axes = ([1, 2] if backend.image_data_format() == "channels_last"
else [2, 3])
self._lamba_2 = layers.Lambda(lambda x: backend.mean(x, rm_axes),
name="reduce_mean")
self._dense = layers.Dense(
num_classes,
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
bias_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name="fc1000",
)
self._activation_2 = layers.Activation("softmax")
def block3(x,
filters,
kernel_size=3,
stride=1,
groups=32,
conv_shortcut=True,
name=None):
"""A residual block.
Arguments:
x: input tensor.
filters: integer, filters of the bottleneck layer.
kernel_size: default 3, kernel size of the bottleneck layer.
stride: default 1, stride of the first layer.
groups: default 32, group size for grouped convolution.
conv_shortcut: default True, use convolution shortcut if True,
otherwise identity shortcut.
name: string, block label.
Returns:
Output tensor for the residual block.
"""
bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1
if conv_shortcut:
shortcut = layers.Conv2D((64 // groups) * filters,
1,
strides=stride,
use_bias=False,
name=name + '_0_conv')(x)
shortcut = layers.BatchNormalization(axis=bn_axis,
epsilon=1.001e-5,
name=name + '_0_bn')(shortcut)
else:
shortcut = x
x = layers.Conv2D(filters, 1, use_bias=False, name=name + '_1_conv')(x)
x = layers.BatchNormalization(axis=bn_axis,
epsilon=1.001e-5,
name=name + '_1_bn')(x)
x = layers.Activation('relu', name=name + '_1_relu')(x)
c = filters // groups
x = layers.ZeroPadding2D(padding=((1, 1), (1, 1)), name=name + '_2_pad')(x)
x = layers.DepthwiseConv2D(kernel_size,
strides=stride,
depth_multiplier=c,
use_bias=False,
name=name + '_2_conv')(x)
x_shape = backend.int_shape(x)[1:-1]
x = layers.Reshape(x_shape + (groups, c, c))(x)
x = layers.Lambda(lambda x: sum(x[:, :, :, :, i] for i in range(c)),
name=name + '_2_reduce')(x)
x = layers.Reshape(x_shape + (filters, ))(x)
x = layers.BatchNormalization(axis=bn_axis,
epsilon=1.001e-5,
name=name + '_2_bn')(x)
x = layers.Activation('relu', name=name + '_2_relu')(x)
x = layers.Conv2D((64 // groups) * filters,
1,
use_bias=False,
name=name + '_3_conv')(x)
x = layers.BatchNormalization(axis=bn_axis,
epsilon=1.001e-5,
name=name + '_3_bn')(x)
x = layers.Add(name=name + '_add')([shortcut, x])
x = layers.Activation('relu', name=name + '_out')(x)
return x
def conv_building_block(input_tensor,
kernel_size,
filters,
stage,
block,
strides=(2, 2),
training=None):
"""A block that has a conv layer at shortcut.
Arguments:
input_tensor: input tensor
kernel_size: default 3, the kernel size of
middle conv layer at main path
filters: list of integers, the filters of 3 conv layer at main path
stage: integer, current stage label, used for generating layer names
block: current block label, used for generating layer names
strides: Strides for the first conv layer in the block.
training: Only used if training keras model with Estimator. In other
scenarios it is handled automatically.
Returns:
Output tensor for the block.
Note that from stage 3,
the first conv layer at main path is with strides=(2, 2)
And the shortcut should have strides=(2, 2) as well
"""
filters1, filters2 = filters
if tf.keras.backend.image_data_format() == 'channels_last':
bn_axis = 3
else:
bn_axis = 1
conv_name_base = 'res' + str(stage) + block + '_branch'
bn_name_base = 'bn' + str(stage) + block + '_branch'
x = layers.Conv2D(filters1,
kernel_size,
strides=strides,
padding='same',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2a')(input_tensor)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2a')(x,
training=training)
x = layers.Activation('relu')(x)
x = layers.Conv2D(filters2,
kernel_size,
padding='same',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2b')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2b')(x,
training=training)
shortcut = layers.Conv2D(
filters2, (1, 1),
strides=strides,
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '1')(input_tensor)
shortcut = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '1')(
shortcut, training=training)
x = layers.add([x, shortcut])
x = layers.Activation('relu')(x)
return x
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 paper:
- [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()`.
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.
"""
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 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
def Xception(include_top=True,
weights='imagenet',
input_tensor=None,
input_shape=None,
pooling=None,
classes=1000,
classifier_activation='softmax'):
"""Instantiates the Xception architecture.
Reference:
- [Xception: Deep Learning with Depthwise Separable Convolutions](
https://arxiv.org/abs/1610.02357) (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 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 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=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,
padding="same",
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),
padding="same",
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
def ResNet50(num_classes):
"""Instantiates the ResNet50 architecture.
Args:
num_classes: `int` number of classes for image classification.
Returns:
A Keras model instance.
"""
# Determine proper input shape
if backend.image_data_format() == 'channels_first':
input_shape = (3, 32, 32)
bn_axis = 1
else:
input_shape = (32, 32, 3)
bn_axis = 3
img_input = layers.Input(shape=input_shape)
x = layers.ZeroPadding2D(padding=(3, 3), name='conv1_pad')(img_input)
x = layers.Conv2D(64, (3, 3), use_bias=False,
strides=(1, 1),
padding='valid',
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name='conv1')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name='bn_conv1')(x)
x = layers.Activation('relu')(x)
x = layers.ZeroPadding2D(padding=(1, 1), name='pool1_pad')(x)
x = layers.MaxPooling2D((3, 3), strides=(2, 2))(x)
x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1))
x = identity_block(x, 3, [64, 64, 256], stage=2, block='b')
x = identity_block(x, 3, [64, 64, 256], stage=2, block='c')
x = conv_block(x, 3, [128, 128, 512], stage=3, block='a')
x = identity_block(x, 3, [128, 128, 512], stage=3, block='b')
x = identity_block(x, 3, [128, 128, 512], stage=3, block='c')
x = identity_block(x, 3, [128, 128, 512], stage=3, block='d')
x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e')
x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f')
x = conv_block(x, 3, [512, 512, 2048], stage=5, block='a')
x = identity_block(x, 3, [512, 512, 2048], stage=5, block='b')
x = identity_block(x, 3, [512, 512, 2048], stage=5, block='c')
x = layers.GlobalAveragePooling2D(name='avg_pool')(x)
x = layers.Dense(
num_classes, activation='softmax',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
bias_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name='fc1000')(x)
# Create model.
return models.Model(img_input, x, name='resnet50')
def PINet_CIFAR10():
## model
input_shape = [32,32,3]
initial_conv_width=3
initial_stride=1
initial_filters=64
initial_pool_width=3
initial_pool_stride=2
use_global_pooling = True
dropout_rate = 0.2
model_input = layers.Input(shape=input_shape)
x = layers.Conv2D(
128,
initial_conv_width,
strides=initial_stride,
padding="same")(model_input)
x = layers.BatchNormalization()(x)
x = layers.Activation("relu")(x)
x = layers.MaxPooling2D(
pool_size=initial_pool_width,
strides=initial_pool_stride,
padding="same")(x)
x = layers.Conv2D(
256,
initial_conv_width,
strides=initial_stride,
padding="same")(x)
x = layers.BatchNormalization()(x)
x = layers.Activation("relu")(x)
x = layers.MaxPooling2D(
pool_size=initial_pool_width,
strides=initial_pool_stride,
padding="same")(x)
x = layers.Conv2D(
512,
initial_conv_width,
strides=initial_stride,
padding="same")(x)
x = layers.BatchNormalization()(x)
x = layers.Activation("relu")(x)
x = layers.MaxPooling2D(
pool_size=initial_pool_width,
strides=initial_pool_stride,
padding="same")(x)
x = layers.Conv2D(
1024,
initial_conv_width,
strides=initial_stride,
padding="same")(x)
x = layers.BatchNormalization()(x)
x = layers.Activation("relu")(x)
if use_global_pooling:
x = layers.GlobalAveragePooling2D()(x)
x_logits1 = layers.Dense(2500, activation="relu")(x)
x_logits1_reshape = layers.Reshape((1,50,50))(x_logits1)
x_logits1_reshape = layers.Permute((2,3,1))(x_logits1_reshape)
x_logits2 = layers.Conv2DTranspose(
3,
50,
strides=initial_stride,
padding="same")(x_logits1_reshape)
x_logits2 = layers.BatchNormalization()(x_logits2)
x_logits2 = layers.Activation("relu")(x_logits2)
model_output = layers.Flatten()(x_logits2)
model = models.Model(model_input, model_output)
return model
def conv_block(input_tensor,
kernel_size,
filters,
stage,
block,
strides=(2, 2)):
"""A block that has a conv layer at shortcut.
# Arguments
input_tensor: input tensor
kernel_size: default 3, the kernel size of
middle conv layer at main path
filters: list of integers, the filters of 3 conv layer at main path
stage: integer, current stage label, used for generating layer names
block: 'a','b'..., current block label, used for generating layer names
strides: Strides for the second conv layer in the block.
# Returns
Output tensor for the block.
Note that from stage 3,
the second conv layer at main path is with strides=(2, 2)
And the shortcut should have strides=(2, 2) as well
"""
filters1, filters2, filters3 = filters
if backend.image_data_format() == 'channels_last':
bn_axis = 3
else:
bn_axis = 1
conv_name_base = 'res' + str(stage) + block + '_branch'
bn_name_base = 'bn' + str(stage) + block + '_branch'
x = layers.Conv2D(filters1, (1, 1),
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2a')(input_tensor)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2a')(x)
x = layers.Activation('relu')(x)
x = layers.Conv2D(filters2,
kernel_size,
strides=strides,
padding='same',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2b')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2b')(x)
x = layers.Activation('relu')(x)
x = layers.Conv2D(filters3, (1, 1),
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '2c')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '2c')(x)
shortcut = layers.Conv2D(
filters3, (1, 1),
strides=strides,
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + '1')(input_tensor)
shortcut = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + '1')(shortcut)
x = layers.add([x, shortcut])
x = layers.Activation('relu')(x)
return x
def shallow_resnet(self,
img_input,
num_classes,
blocks,
num_filters_per_block,
dtype='float32',
batch_size=None,
use_l2_regularizer=True,
reduce_mean=False,
softmax=True):
"""Instantiates the ResNet50 architecture.
Args:
num_classes: `int` number of classes for image classification.
dtype: dtype to use float32 or float16 are most common.
batch_size: Size of the batches for each step.
use_l2_regularizer: whether to use L2 regularizer on Conv/Dense layer.
Returns:
A tensor of final layer
"""
# input_shape = (224, 224, 3)
# img_input = layers.Input(
# shape=input_shape, dtype=dtype, batch_size=batch_size)
if backend.image_data_format() == 'channels_first':
x = layers.Lambda(
lambda x: backend.permute_dimensions(x, (0, 3, 1, 2)),
name='transpose')(img_input)
bn_axis = 1
else: # channels_last
x = img_input
bn_axis = 3
# x = layers.ZeroPadding2D(padding=(3, 3), name='conv1_pad')(x)
x = self._resnet_layers['conv1'](x)
x = self._resnet_layers['bn_conv1'](x)
x = layers.Activation('relu')(x)
# x = layers.MaxPooling2D((3, 3), strides=(2, 2), padding='same')(x)
for i, (num_block,
num_filter) in enumerate(zip(blocks, num_filters_per_block)):
stage_id = i + 1
x = self.conv_block(x, stage=stage_id, block='a_')
for j in range(num_block):
x = self.identity_block(x, stage=stage_id, block='b_' + str(j))
x = self.identity_block(x, stage=stage_id, block='c_' + str(j))
rm_axes = [
1, 2
] if backend.image_data_format() == 'channels_last' else [2, 3]
if reduce_mean:
x = layers.Lambda(lambda x: backend.mean(x, rm_axes),
name='reduce_mean')(x)
# TODO(reedwm): Remove manual casts once mixed precision can be enabled with a
# single line of code.
x = backend.cast(x, 'float32')
# =============================================================================
# if softmax:
# x = layers.Activation('softmax')(x)
# =============================================================================
# Create model.
return x
def resnet50(num_classes, batch_size=None, use_l2_regularizer=True):
"""Instantiates the ResNet50 architecture.
Args:
num_classes: `int` number of classes for image classification.
batch_size: Size of the batches for each step.
use_l2_regularizer: whether to use L2 regularizer on Conv/Dense layer.
Returns:
A Keras model instance.
"""
input_shape = (224, 224, 3)
img_input = layers.Input(shape=input_shape, batch_size=batch_size)
if backend.image_data_format() == 'channels_first':
x = layers.Lambda(
lambda x: backend.permute_dimensions(x, (0, 3, 1, 2)),
name='transpose')(img_input)
bn_axis = 1
else: # channels_last
x = img_input
bn_axis = 3
x = layers.ZeroPadding2D(padding=(3, 3), name='conv1_pad')(x)
x = layers.Conv2D(
64, (7, 7),
strides=(2, 2),
padding='valid',
use_bias=False,
kernel_initializer='he_normal',
kernel_regularizer=_gen_l2_regularizer(use_l2_regularizer),
name='conv1')(x)
x = layers.BatchNormalization(axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name='bn_conv1')(x)
x = layers.Activation('relu')(x)
x = layers.MaxPooling2D((3, 3), strides=(2, 2), padding='same')(x)
x = conv_block(x,
3, [64, 64, 256],
stage=2,
block='a',
strides=(1, 1),
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [64, 64, 256],
stage=2,
block='b',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [64, 64, 256],
stage=2,
block='c',
use_l2_regularizer=use_l2_regularizer)
x = conv_block(x,
3, [128, 128, 512],
stage=3,
block='a',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [128, 128, 512],
stage=3,
block='b',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [128, 128, 512],
stage=3,
block='c',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [128, 128, 512],
stage=3,
block='d',
use_l2_regularizer=use_l2_regularizer)
x = conv_block(x,
3, [256, 256, 1024],
stage=4,
block='a',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [256, 256, 1024],
stage=4,
block='b',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [256, 256, 1024],
stage=4,
block='c',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [256, 256, 1024],
stage=4,
block='d',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [256, 256, 1024],
stage=4,
block='e',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [256, 256, 1024],
stage=4,
block='f',
use_l2_regularizer=use_l2_regularizer)
x = conv_block(x,
3, [512, 512, 2048],
stage=5,
block='a',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [512, 512, 2048],
stage=5,
block='b',
use_l2_regularizer=use_l2_regularizer)
x = identity_block(x,
3, [512, 512, 2048],
stage=5,
block='c',
use_l2_regularizer=use_l2_regularizer)
rm_axes = [1, 2
] if backend.image_data_format() == 'channels_last' else [2, 3]
x = layers.Lambda(lambda x: backend.mean(x, rm_axes),
name='reduce_mean')(x)
x = layers.Dense(
num_classes,
kernel_initializer=initializers.RandomNormal(stddev=0.01),
kernel_regularizer=_gen_l2_regularizer(use_l2_regularizer),
bias_regularizer=_gen_l2_regularizer(use_l2_regularizer),
name='fc1000')(x)
# A softmax that is followed by the model loss must be done cannot be done
# in float16 due to numeric issues. So we pass dtype=float32.
x = layers.Activation('softmax', dtype='float32')(x)
# Create model.
return models.Model(img_input, x, name='resnet50')
def ResNet50Beta(batch_input_shape,
include_top=True,
weights='imagenet',
fusion_mode='bgr_hha',
classes=1000,
dilated=True,
multi_grid=False,
multi_dilation=None,
conv_trainable=True):
"""Instantiates the ResNet50 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 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.
# 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')
img_input = klayers.Input(shape=batch_input_shape[1:4],
batch_size=batch_input_shape[0])
if fusion_mode == 'bgr_hha_gw':
x, xyz = ilayers.GWConv(sizes=(3, 3),
strides=(2, 2),
rates=(1, 1),
padding='same',
delta=0.5,
out_c=64,
activation=None,
name='gw_conv1_1')(img_input)
x = klayers.Conv2D(64, (3, 3),
strides=(3, 3),
name='custom_entry_flow_conv1_1',
trainable=conv_trainable,
use_bias=False,
padding='valid')(x)
else:
# x = klayers.ZeroPadding2D(padding=(3, 3), name='conv1_pad')(img_input)
x = klayers.Conv2D(64, (3, 3),
strides=(2, 2),
padding='same',
kernel_initializer='he_uniform',
trainable=True,
name='conv1' if batch_input_shape[-1] == 3 else
'custom_conv1')(img_input)
x = klayers.BatchNormalizationV2(name='bn_conv1')(x)
x = klayers.Activation('relu')(x)
x = klayers.ZeroPadding2D(padding=(1, 1), name='pool1_pad')(x)
x = klayers.MaxPooling2D((3, 3), strides=(2, 2))(x)
x = resnet_block(x,
num_units=3,
base_filters=64,
stage=2,
stride=1,
conv_trainable=conv_trainable)
x = resnet_block(x,
num_units=4,
base_filters=128,
stage=3,
stride=2,
conv_trainable=conv_trainable)
if dilated:
if multi_grid:
x = resnet_block(x,
num_units=6,
base_filters=256,
stage=4,
dilation=2,
stride=1,
conv_trainable=conv_trainable)
x = resnet_block(x,
num_units=3,
base_filters=512,
stage=5,
dilation=4,
stride=1,
multi_grid=multi_grid,
multi_dilation=multi_dilation,
conv_trainable=conv_trainable)
else:
x = resnet_block(x,
num_units=6,
base_filters=256,
stage=4,
dilation=2,
stride=1,
conv_trainable=conv_trainable)
x = resnet_block(x,
num_units=3,
base_filters=512,
stage=5,
dilation=4,
stride=1,
conv_trainable=conv_trainable)
else:
x = resnet_block(x,
num_units=6,
base_filters=256,
stage=4,
stride=2,
conv_trainable=conv_trainable)
x = resnet_block(x,
num_units=3,
base_filters=512,
stage=5,
stride=2,
conv_trainable=conv_trainable)
if include_top:
x = klayers.GlobalAveragePooling2D(name='avg_pool')(x)
x = klayers.Dense(classes, activation='softmax', name='fc1000')(x)
# Create model.
model = tf.keras.models.Model(img_input, x, name='resnet50_beta')
# Load weights.
if weights == 'imagenet':
if include_top:
weights_path = tf.keras.utils.get_file(
'resnet50_weights_tf_dim_ordering_tf_kernels.h5',
WEIGHTS_PATH,
cache_subdir='models',
md5_hash='a7b3fe01876f51b976af0dea6bc144eb')
else:
weights_path = tf.keras.utils.get_file(
'resnet50_weights_tf_dim_ordering_tf_kernels_notop.h5',
WEIGHTS_PATH_NO_TOP,
cache_subdir='models',
md5_hash='a268eb855778b3df3c7506639542a6af')
model.load_weights(weights_path, by_name=True)
elif weights is not None:
model.load_weights(weights, by_name=True)
return model
def __init__(self, kernel_size, filters, stage, block, strides=(2, 2)):
super(ConvBlock, self).__init__(name="conv_block")
filters1, filters2, filters3 = filters
if backend.image_data_format() == "channels_last":
bn_axis = 3
else:
bn_axis = 1
conv_name_base = "res" + str(stage) + block + "_branch"
bn_name_base = "bn" + str(stage) + block + "_branch"
self._conv2d_1 = layers.Conv2D(
filters1,
(1, 1),
use_bias=False,
kernel_initializer="he_normal",
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + "2a",
)
self._bn_1 = layers.BatchNormalization(
axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + "2a",
)
self._activation_1 = layers.Activation("relu")
self._conv2d_2 = layers.Conv2D(
filters2,
kernel_size,
strides=strides,
padding="same",
use_bias=False,
kernel_initializer="he_normal",
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + "2b",
)
self._bn_2 = layers.BatchNormalization(
axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + "2b",
)
self._activation_2 = layers.Activation("relu")
self._conv2d_3 = layers.Conv2D(
filters3,
(1, 1),
use_bias=False,
kernel_initializer="he_normal",
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + "2c",
)
self._bn_3 = layers.BatchNormalization(
axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + "2c",
)
self._shortcut = layers.Conv2D(
filters3,
(1, 1),
strides=strides,
use_bias=False,
kernel_initializer="he_normal",
kernel_regularizer=regularizers.l2(L2_WEIGHT_DECAY),
name=conv_name_base + "1",
)
self._bn_4 = layers.BatchNormalization(
axis=bn_axis,
momentum=BATCH_NORM_DECAY,
epsilon=BATCH_NORM_EPSILON,
name=bn_name_base + "1",
)
self._activation_4 = layers.Activation("relu")
def conv_block(input_tensor,
kernel_size,
filters,
stage,
block,
strides=2,
dilation=1,
conv_trainable=True):
"""A block that has a conv layer at shortcut.
# Arguments
input_tensor: input tensor
kernel_size: default 3, the kernel size of
middle conv layer at main path
filters: list of integers, the filters of 3 conv layer at main path
stage: integer, current stage label, used for generating layer names
block: 'a','b'..., current block label, used for generating layer names
strides: Strides for the first conv layer in the block.
# Returns
Output tensor for the block.
Note that from stage 3,
the first conv layer at main path is with strides=(2, 2)
And the shortcut should have strides=(2, 2) as well
"""
filters1, filters2, filters3 = filters
conv_name_base = 'res' + str(stage) + block + '_branch'
bn_name_base = 'bn' + str(stage) + block + '_branch'
x = klayers.Conv2D(filters1, (1, 1),
strides=strides,
kernel_initializer='he_uniform',
trainable=conv_trainable,
name=conv_name_base + '2a')(input_tensor)
x = klayers.BatchNormalizationV2(name=bn_name_base + '2a')(x)
x = klayers.Activation('relu')(x)
x = klayers.Conv2D(filters2,
kernel_size,
padding='same',
dilation_rate=dilation,
kernel_initializer='he_uniform',
trainable=conv_trainable,
name=conv_name_base + '2b')(x)
x = klayers.BatchNormalizationV2(name=bn_name_base + '2b')(x)
x = klayers.Activation('relu')(x)
x = klayers.Conv2D(filters3, (1, 1),
kernel_initializer='he_uniform',
trainable=conv_trainable,
name=conv_name_base + '2c')(x)
x = klayers.BatchNormalizationV2(name=bn_name_base + '2c')(x)
shortcut = klayers.Conv2D(filters3, (1, 1),
strides=strides,
kernel_initializer='he_uniform',
trainable=conv_trainable,
name=conv_name_base + '1')(input_tensor)
shortcut = klayers.BatchNormalizationV2(name=bn_name_base + '1')(shortcut)
x = klayers.add([x, shortcut])
x = klayers.Activation('relu')(x)
return x
def block(inputs,
activation='swish',
drop_rate=0.,
name='',
filters_in=32,
filters_out=16,
kernel_size=3,
strides=1,
expand_ratio=1,
se_ratio=0.,
id_skip=True):
"""An inverted residual block.
Arguments:
inputs: input tensor.
activation: activation function.
drop_rate: float between 0 and 1, fraction of the input units to drop.
name: string, block label.
filters_in: integer, the number of input filters.
filters_out: integer, the number of output filters.
kernel_size: integer, the dimension of the convolution window.
strides: integer, the stride of the convolution.
expand_ratio: integer, scaling coefficient for the input filters.
se_ratio: float between 0 and 1, fraction to squeeze the input filters.
id_skip: boolean.
Returns:
output tensor for the block.
"""
bn_axis = 3 if backend.image_data_format() == 'channels_last' else 1
# Expansion phase
filters = filters_in * expand_ratio
if expand_ratio != 1:
x = layers.Conv2D(
filters,
1,
padding='same',
use_bias=False,
kernel_initializer=CONV_KERNEL_INITIALIZER,
name=name + 'expand_conv')(
inputs)
x = layers.BatchNormalization(axis=bn_axis, name=name + 'expand_bn')(x)
x = layers.Activation(activation, name=name + 'expand_activation')(x)
else:
x = inputs
# Depthwise Convolution
if strides == 2:
x = layers.ZeroPadding2D(
padding=imagenet_utils.correct_pad(x, kernel_size),
name=name + 'dwconv_pad')(x)
conv_pad = 'valid'
else:
conv_pad = 'same'
x = layers.DepthwiseConv2D(
kernel_size,
strides=strides,
padding=conv_pad,
use_bias=False,
depthwise_initializer=CONV_KERNEL_INITIALIZER,
name=name + 'dwconv')(x)
x = layers.BatchNormalization(axis=bn_axis, name=name + 'bn')(x)
x = layers.Activation(activation, name=name + 'activation')(x)
# Squeeze and Excitation phase
if 0 < se_ratio <= 1:
filters_se = max(1, int(filters_in * se_ratio))
se = layers.GlobalAveragePooling2D(name=name + 'se_squeeze')(x)
se = layers.Reshape((1, 1, filters), name=name + 'se_reshape')(se)
se = layers.Conv2D(
filters_se,
1,
padding='same',
activation=activation,
kernel_initializer=CONV_KERNEL_INITIALIZER,
name=name + 'se_reduce')(
se)
se = layers.Conv2D(
filters,
1,
padding='same',
activation='sigmoid',
kernel_initializer=CONV_KERNEL_INITIALIZER,
name=name + 'se_expand')(se)
x = layers.multiply([x, se], name=name + 'se_excite')
# Output phase
x = layers.Conv2D(
filters_out,
1,
padding='same',
use_bias=False,
kernel_initializer=CONV_KERNEL_INITIALIZER,
name=name + 'project_conv')(x)
x = layers.BatchNormalization(axis=bn_axis, name=name + 'project_bn')(x)
if id_skip and strides == 1 and filters_in == filters_out:
if drop_rate > 0:
x = layers.Dropout(
drop_rate, noise_shape=(None, 1, 1, 1), name=name + 'drop')(x)
x = layers.add([x, inputs], name=name + 'add')
return x
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 = 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)), 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=1.001e-5,
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
def inception_resnet_block(x, scale, block_type, block_idx, activation='relu'):
"""Adds a Inception-ResNet block.
This function builds 3 types of Inception-ResNet blocks mentioned
in the paper, controlled by the `block_type` argument (which is the
block name used in the official TF-slim implementation):
- Inception-ResNet-A: `block_type='block35'`
- Inception-ResNet-B: `block_type='block17'`
- Inception-ResNet-C: `block_type='block8'`
Arguments:
x: input tensor.
scale: scaling factor to scale the residuals (i.e., the output of
passing `x` through an inception module) before adding them
to the shortcut branch.
Let `r` be the output from the residual branch,
the output of this block will be `x + scale * r`.
block_type: `'block35'`, `'block17'` or `'block8'`, determines
the network structure in the residual branch.
block_idx: an `int` used for generating layer names.
The Inception-ResNet blocks
are repeated many times in this network.
We use `block_idx` to identify
each of the repetitions. For example,
the first Inception-ResNet-A block
will have `block_type='block35', block_idx=0`,
and the layer names will have
a common prefix `'block35_0'`.
activation: activation function to use at the end of the block
(see [activations](../activations.md)).
When `activation=None`, no activation is applied
(i.e., "linear" activation: `a(x) = x`).
Returns:
Output tensor for the block.
Raises:
ValueError: if `block_type` is not one of `'block35'`,
`'block17'` or `'block8'`.
"""
if block_type == 'block35':
branch_0 = conv2d_bn(x, 32, 1)
branch_1 = conv2d_bn(x, 32, 1)
branch_1 = conv2d_bn(branch_1, 32, 3)
branch_2 = conv2d_bn(x, 32, 1)
branch_2 = conv2d_bn(branch_2, 48, 3)
branch_2 = conv2d_bn(branch_2, 64, 3)
branches = [branch_0, branch_1, branch_2]
elif block_type == 'block17':
branch_0 = conv2d_bn(x, 192, 1)
branch_1 = conv2d_bn(x, 128, 1)
branch_1 = conv2d_bn(branch_1, 160, [1, 7])
branch_1 = conv2d_bn(branch_1, 192, [7, 1])
branches = [branch_0, branch_1]
elif block_type == 'block8':
branch_0 = conv2d_bn(x, 192, 1)
branch_1 = conv2d_bn(x, 192, 1)
branch_1 = conv2d_bn(branch_1, 224, [1, 3])
branch_1 = conv2d_bn(branch_1, 256, [3, 1])
branches = [branch_0, branch_1]
else:
raise ValueError('Unknown Inception-ResNet block type. '
'Expects "block35", "block17" or "block8", '
'but got: ' + str(block_type))
block_name = block_type + '_' + str(block_idx)
channel_axis = 1 if backend.image_data_format() == 'channels_first' else 3
mixed = layers.Concatenate(
axis=channel_axis, name=block_name + '_mixed')(
branches)
up = conv2d_bn(
mixed,
backend.int_shape(x)[channel_axis],
1,
activation=None,
use_bias=True,
name=block_name + '_conv')
x = layers.Lambda(
lambda inputs, scale: inputs[0] + inputs[1] * scale,
output_shape=backend.int_shape(x)[1:],
arguments={'scale': scale},
name=block_name)([x, up])
if activation is not None:
x = layers.Activation(activation, name=block_name + '_ac')(x)
return x
def _reduction_a_cell(ip, p, filters, block_id=None):
"""Adds a Reduction cell for NASNet-A (Fig. 4 in the paper).
Arguments:
ip: Input tensor `x`
p: Input tensor `p`
filters: Number of output filters
block_id: String block_id
Returns:
A Keras tensor
"""
channel_dim = 1 if backend.image_data_format() == 'channels_first' else -1
with backend.name_scope('reduction_A_block_%s' % block_id):
p = _adjust_block(p, ip, filters, block_id)
h = layers.Activation('relu')(ip)
h = layers.Conv2D(
filters, (1, 1),
strides=(1, 1),
padding='same',
name='reduction_conv_1_%s' % block_id,
use_bias=False,
kernel_initializer='he_normal')(
h)
h = layers.BatchNormalization(
axis=channel_dim,
momentum=0.9997,
epsilon=1e-3,
name='reduction_bn_1_%s' % block_id)(
h)
h3 = layers.ZeroPadding2D(
padding=imagenet_utils.correct_pad(h, 3),
name='reduction_pad_1_%s' % block_id)(
h)
with backend.name_scope('block_1'):
x1_1 = _separable_conv_block(
h,
filters, (5, 5),
strides=(2, 2),
block_id='reduction_left1_%s' % block_id)
x1_2 = _separable_conv_block(
p,
filters, (7, 7),
strides=(2, 2),
block_id='reduction_right1_%s' % block_id)
x1 = layers.add([x1_1, x1_2], name='reduction_add_1_%s' % block_id)
with backend.name_scope('block_2'):
x2_1 = layers.MaxPooling2D((3, 3),
strides=(2, 2),
padding='valid',
name='reduction_left2_%s' % block_id)(
h3)
x2_2 = _separable_conv_block(
p,
filters, (7, 7),
strides=(2, 2),
block_id='reduction_right2_%s' % block_id)
x2 = layers.add([x2_1, x2_2], name='reduction_add_2_%s' % block_id)
with backend.name_scope('block_3'):
x3_1 = layers.AveragePooling2D((3, 3),
strides=(2, 2),
padding='valid',
name='reduction_left3_%s' % block_id)(
h3)
x3_2 = _separable_conv_block(
p,
filters, (5, 5),
strides=(2, 2),
block_id='reduction_right3_%s' % block_id)
x3 = layers.add([x3_1, x3_2], name='reduction_add3_%s' % block_id)
with backend.name_scope('block_4'):
x4 = layers.AveragePooling2D((3, 3),
strides=(1, 1),
padding='same',
name='reduction_left4_%s' % block_id)(
x1)
x4 = layers.add([x2, x4])
with backend.name_scope('block_5'):
x5_1 = _separable_conv_block(
x1, filters, (3, 3), block_id='reduction_left4_%s' % block_id)
x5_2 = layers.MaxPooling2D((3, 3),
strides=(2, 2),
padding='valid',
name='reduction_right5_%s' % block_id)(
h3)
x5 = layers.add([x5_1, x5_2], name='reduction_add4_%s' % block_id)
x = layers.concatenate([x2, x3, x4, x5],
axis=channel_dim,
name='reduction_concat_%s' % block_id)
return x, ip
