def SepConv_BN(x,
filters,
prefix,
stride=1,
kernel_size=3,
rate=1,
depth_activation=False,
epsilon=1e-3,
use_coordconv=True):
""" SepConv with BN between depthwise & pointwise. Optionally add activation after BN
Implements right "same" padding for even kernel sizes
Args:
x: input tensor
filters: num of filters in pointwise convolution
prefix: prefix before name
stride: stride at depthwise conv
kernel_size: kernel size for depthwise convolution
rate: atrous rate for depthwise convolution
depth_activation: flag to use activation between depthwise & poinwise convs
epsilon: epsilon to use in BN layer
"""
if stride == 1:
depth_padding = 'same'
else:
kernel_size_effective = kernel_size + (kernel_size - 1) * (rate - 1)
pad_total = kernel_size_effective - 1
pad_beg = pad_total // 2
pad_end = pad_total - pad_beg
x = ZeroPadding2D((pad_beg, pad_end))(x)
depth_padding = 'valid'
if not depth_activation:
x = Activation('relu')(x)
x = DepthwiseConv2D((kernel_size, kernel_size),
strides=(stride, stride),
dilation_rate=(rate, rate),
padding=depth_padding,
use_bias=False,
name=prefix + '_depthwise')(x)
x = BatchNormalization(name=prefix + '_depthwise_BN', epsilon=epsilon)(x)
if depth_activation:
x = Activation('relu')(x)
if use_coordconv:
x = CoordinateChannel2D(use_radius=True)(x)
x = Conv2D(filters, (1, 1),
padding='same',
use_bias=False,
name=prefix + '_pointwise')(x)
x = BatchNormalization(name=prefix + '_pointwise_BN', epsilon=epsilon)(x)
if depth_activation:
x = Activation('relu')(x)
return x
def res(inputs, bn=True):
n = int(inputs.shape[-1])
x = CoordinateChannel2D()(inputs)
# x=(inputs)
c1 = relu()(Conv2D(n, 3, padding='same')(x))
c2 = relu()(Conv2D(n, 3, padding='same')(c1))
m = add([c2, inputs])
if bn:
m = BN()(m)
return m
plt.imshow(np.sum(train_onehot, axis=0)[:, :, 0], cmap='gray')
plt.title('Train One-hot dataset')
plt.show()
plt.imshow(np.sum(test_onehot, axis=0)[:, :, 0], cmap='gray')
plt.title('Test One-hot dataset')
plt.show()
# flatten the datasets
train_onehot = train_onehot.reshape((-1, 64 * 64))
test_onehot = test_onehot.reshape((-1, 64 * 64))
# model definition
ip = Input(shape=(64, 64, 2))
x = CoordinateChannel2D()(ip)
x = Conv2D(32, (1, 1), padding='same', activation='relu')(x)
x = Conv2D(32, (1, 1), padding='same', activation='relu')(x)
x = Conv2D(64, (1, 1), padding='same', activation='relu')(x)
x = Conv2D(64, (1, 1), padding='same', activation='relu')(x)
x = Conv2D(1, (1, 1), padding='same', activation='linear')(x)
x = Flatten()(x)
x = Softmax(axis=-1)(x)
model = Model(ip, x)
print(model.summary())
optimizer = Adam(lr=1e-2)
model.compile(optimizer, 'categorical_crossentropy', metrics=['accuracy'])
def Deeplabv3(weights='pascal_voc',
input_tensor=None,
input_shape=(512, 512, 3),
classes=21,
backbone='mobilenetv2',
OS=16,
alpha=1.,
use_coordconv=True):
""" Instantiates the Deeplabv3+ architecture
Optionally loads weights pre-trained
on PASCAL VOC. This model is available for TensorFlow only,
and can only be used with inputs following the TensorFlow
data format `(width, height, channels)`.
# Arguments
weights: one of 'pascal_voc' (pre-trained on pascal voc)
or None (random initialization)
input_tensor: optional Keras tensor (i.e. output of `layers.Input()`)
to use as image input for the model.
input_shape: shape of input image. format HxWxC
PASCAL VOC model was trained on (512,512,3) images
classes: number of desired classes. If classes != 21,
last layer is initialized randomly
backbone: backbone to use. one of {'xception','mobilenetv2'}
OS: determines input_shape/feature_extractor_output ratio. One of {8,16}.
Used only for xception backbone.
alpha: controls the width of the MobileNetV2 network. This is known as the
width multiplier in the MobileNetV2 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.
Used only for mobilenetv2 backbone
# Returns
A Keras model instance.
# Raises
RuntimeError: If attempting to run this model with a
backend that does not support separable convolutions.
ValueError: in case of invalid argument for `weights` or `backbone`
"""
if not (weights in {'pascal_voc', None}):
raise ValueError('The `weights` argument should be either '
'`None` (random initialization) or `pascal_voc` '
'(pre-trained on PASCAL VOC)')
if K.backend() != 'tensorflow':
raise RuntimeError('The Deeplabv3+ model is only available with '
'the TensorFlow backend.')
if not (backbone in {'xception', 'mobilenetv2'}):
raise ValueError('The `backbone` argument should be either '
'`xception` or `mobilenetv2` ')
if input_tensor is None:
img_input = Input(shape=input_shape)
else:
if not K.is_keras_tensor(input_tensor):
img_input = Input(tensor=input_tensor, shape=input_shape)
else:
img_input = input_tensor
batches_input = img_input
if use_coordconv: # implemented as in image-classification task in resnet50 (Section S5, page 15)
batches_input = CoordinateChannel2D(use_radius=True)(batches_input)
batches_input = Conv2D(
8, (1, 1), padding='same',
name='8_channels_coordconv_input')(batches_input)
if backbone == 'xception':
if OS == 8:
entry_block3_stride = 1
middle_block_rate = 2 # ! Not mentioned in paper, but required
exit_block_rates = (2, 4)
atrous_rates = (12, 24, 36)
else:
entry_block3_stride = 2
middle_block_rate = 1
exit_block_rates = (1, 2)
atrous_rates = (6, 12, 18)
x = Conv2D(32, (3, 3),
strides=(2, 2),
name='entry_flow_conv1_1',
use_bias=False,
padding='same')(batches_input)
x = BatchNormalization(name='entry_flow_conv1_1_BN')(x)
x = Activation('relu')(x)
x = _conv2d_same(x, 64, 'entry_flow_conv1_2', kernel_size=3, stride=1)
x = BatchNormalization(name='entry_flow_conv1_2_BN')(x)
x = Activation('relu')(x)
x = _xception_block(x, [128, 128, 128],
'entry_flow_block1',
skip_connection_type='conv',
stride=2,
depth_activation=False)
x, skip1 = _xception_block(x, [256, 256, 256],
'entry_flow_block2',
skip_connection_type='conv',
stride=2,
depth_activation=False,
return_skip=True)
x = _xception_block(x, [728, 728, 728],
'entry_flow_block3',
skip_connection_type='conv',
stride=entry_block3_stride,
depth_activation=False)
for i in range(16):
x = _xception_block(x, [728, 728, 728],
'middle_flow_unit_{}'.format(i + 1),
skip_connection_type='sum',
stride=1,
rate=middle_block_rate,
depth_activation=False)
x = _xception_block(x, [728, 1024, 1024],
'exit_flow_block1',
skip_connection_type='conv',
stride=1,
rate=exit_block_rates[0],
depth_activation=False)
x = _xception_block(x, [1536, 1536, 2048],
'exit_flow_block2',
skip_connection_type='none',
stride=1,
rate=exit_block_rates[1],
depth_activation=True)
else:
OS = 8
first_block_filters = _make_divisible(32 * alpha, 8)
x = Conv2D(first_block_filters,
kernel_size=3,
strides=(2, 2),
padding='same',
use_bias=False,
name='Conv')(batches_input)
x = BatchNormalization(epsilon=1e-3, momentum=0.999, name='Conv_BN')(x)
x = Activation(relu6, name='Conv_Relu6')(x)
x = _inverted_res_block(x,
filters=16,
alpha=alpha,
stride=1,
expansion=1,
block_id=0,
skip_connection=False,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=24,
alpha=alpha,
stride=2,
expansion=6,
block_id=1,
skip_connection=False,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=24,
alpha=alpha,
stride=1,
expansion=6,
block_id=2,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=32,
alpha=alpha,
stride=2,
expansion=6,
block_id=3,
skip_connection=False,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=32,
alpha=alpha,
stride=1,
expansion=6,
block_id=4,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=32,
alpha=alpha,
stride=1,
expansion=6,
block_id=5,
skip_connection=True,
use_coordconv=use_coordconv)
# stride in block 6 changed from 2 -> 1, so we need to use rate = 2
x = _inverted_res_block(
x,
filters=64,
alpha=alpha,
stride=1, # 1!
expansion=6,
block_id=6,
skip_connection=False,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=64,
alpha=alpha,
stride=1,
rate=2,
expansion=6,
block_id=7,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=64,
alpha=alpha,
stride=1,
rate=2,
expansion=6,
block_id=8,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=64,
alpha=alpha,
stride=1,
rate=2,
expansion=6,
block_id=9,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=96,
alpha=alpha,
stride=1,
rate=2,
expansion=6,
block_id=10,
skip_connection=False,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=96,
alpha=alpha,
stride=1,
rate=2,
expansion=6,
block_id=11,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=96,
alpha=alpha,
stride=1,
rate=2,
expansion=6,
block_id=12,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(
x,
filters=160,
alpha=alpha,
stride=1,
rate=2, # 1!
expansion=6,
block_id=13,
skip_connection=False,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=160,
alpha=alpha,
stride=1,
rate=4,
expansion=6,
block_id=14,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=160,
alpha=alpha,
stride=1,
rate=4,
expansion=6,
block_id=15,
skip_connection=True,
use_coordconv=use_coordconv)
x = _inverted_res_block(x,
filters=320,
alpha=alpha,
stride=1,
rate=4,
expansion=6,
block_id=16,
skip_connection=False,
use_coordconv=use_coordconv)
# end of feature extractor
# branching for Atrous Spatial Pyramid Pooling
# Image Feature branch
#out_shape = int(np.ceil(input_shape[0] / OS))
b4 = AveragePooling2D(pool_size=(int(np.ceil(input_shape[0] / OS)),
int(np.ceil(input_shape[1] / OS))))(x)
b4 = Conv2D(256, (1, 1),
padding='same',
use_bias=False,
name='image_pooling')(b4)
b4 = BatchNormalization(name='image_pooling_BN', epsilon=1e-5)(b4)
b4 = Activation('relu')(b4)
b4 = BilinearUpsampling((int(np.ceil(input_shape[0] / OS)),
int(np.ceil(input_shape[1] / OS))))(b4)
# simple 1x1
if use_coordconv:
x = CoordinateChannel2D(use_radius=True)(x)
b0 = Conv2D(256, (1, 1), padding='same', use_bias=False, name='aspp0')(x)
b0 = BatchNormalization(name='aspp0_BN', epsilon=1e-5)(b0)
b0 = Activation('relu', name='aspp0_activation')(b0)
# there are only 2 branches in mobilenetV2. not sure why
if backbone == 'xception':
# rate = 6 (12)
b1 = SepConv_BN(x,
256,
'aspp1',
rate=atrous_rates[0],
depth_activation=True,
epsilon=1e-5,
use_coordconv=use_coordconv)
# rate = 12 (24)
b2 = SepConv_BN(x,
256,
'aspp2',
rate=atrous_rates[1],
depth_activation=True,
epsilon=1e-5,
use_coordconv=use_coordconv)
# rate = 18 (36)
b3 = SepConv_BN(x,
256,
'aspp3',
rate=atrous_rates[2],
depth_activation=True,
epsilon=1e-5,
use_coordconv=use_coordconv)
# concatenate ASPP branches & project
x = Concatenate()([b4, b0, b1, b2, b3])
else:
x = Concatenate()([b4, b0])
if use_coordconv:
x = CoordinateChannel2D(use_radius=True)(x)
x = Conv2D(256, (1, 1),
padding='same',
use_bias=False,
name='concat_projection')(x)
x = BatchNormalization(name='concat_projection_BN', epsilon=1e-5)(x)
x = Activation('relu')(x)
x = Dropout(0.1)(x)
# DeepLab v.3+ decoder
if backbone == 'xception':
# Feature projection
# x4 (x2) block
x = BilinearUpsampling(output_size=(int(np.ceil(input_shape[0] / 4)),
int(np.ceil(input_shape[1] /
4))))(x)
dec_skip1 = Conv2D(48, (1, 1),
padding='same',
use_bias=False,
name='feature_projection0')(skip1)
dec_skip1 = BatchNormalization(name='feature_projection0_BN',
epsilon=1e-5)(dec_skip1)
dec_skip1 = Activation('relu')(dec_skip1)
x = Concatenate()([x, dec_skip1])
x = SepConv_BN(x,
256,
'decoder_conv0',
depth_activation=True,
epsilon=1e-5,
use_coordconv=use_coordconv)
x = SepConv_BN(x,
256,
'decoder_conv1',
depth_activation=True,
epsilon=1e-5,
use_coordconv=use_coordconv)
# you can use it with arbitary number of classes
if classes == 21:
last_layer_name = 'logits_semantic'
else:
last_layer_name = 'custom_logits_semantic'
if use_coordconv:
x = CoordinateChannel2D(use_radius=True)(x)
x = Conv2D(classes, (1, 1), padding='same', name=last_layer_name)(x)
x = BilinearUpsampling(output_size=(input_shape[0], input_shape[1]))(x)
# Ensure that the model takes into account
# any potential predecessors of `input_tensor`.
if input_tensor is not None:
inputs = get_source_inputs(input_tensor)
else:
inputs = img_input
model = Model(inputs, x, name='deeplabv3+')
# load weights
if weights == 'pascal_voc':
if backbone == 'xception':
weights_path = get_file(
'deeplabv3_xception_tf_dim_ordering_tf_kernels.h5',
WEIGHTS_PATH_X,
cache_subdir='models')
else:
weights_path = get_file(
'deeplabv3_mobilenetv2_tf_dim_ordering_tf_kernels.h5',
WEIGHTS_PATH_MOBILE,
cache_subdir='models')
model.load_weights(weights_path, by_name=True)
return model
def _inverted_res_block(inputs,
expansion,
stride,
alpha,
filters,
block_id,
skip_connection,
rate=1,
use_coordconv=True):
in_channels = inputs._keras_shape[-1]
pointwise_conv_filters = int(filters * alpha)
pointwise_filters = _make_divisible(pointwise_conv_filters, 8)
x = inputs
prefix = 'expanded_conv_{}_'.format(block_id)
if block_id:
# Expand
if use_coordconv:
x = CoordinateChannel2D(use_radius=True)(x)
x = Conv2D(expansion * in_channels,
kernel_size=1,
padding='same',
use_bias=False,
activation=None,
name=prefix + 'expand')(x)
x = BatchNormalization(epsilon=1e-3,
momentum=0.999,
name=prefix + 'expand_BN')(x)
x = Activation(relu6, name=prefix + 'expand_relu')(x)
else:
prefix = 'expanded_conv_'
# Depthwise
x = DepthwiseConv2D(kernel_size=3,
strides=stride,
activation=None,
use_bias=False,
padding='same',
dilation_rate=(rate, rate),
name=prefix + 'depthwise')(x)
x = BatchNormalization(epsilon=1e-3,
momentum=0.999,
name=prefix + 'depthwise_BN')(x)
x = Activation(relu6, name=prefix + 'depthwise_relu')(x)
# Project
if use_coordconv:
x = CoordinateChannel2D(use_radius=True)(x)
x = Conv2D(pointwise_filters,
kernel_size=1,
padding='same',
use_bias=False,
activation=None,
name=prefix + 'project')(x)
x = BatchNormalization(epsilon=1e-3,
momentum=0.999,
name=prefix + 'project_BN')(x)
if skip_connection:
return Add(name=prefix + 'add')([inputs, x])
# if in_channels == pointwise_filters and stride == 1:
# return Add(name='res_connect_' + str(block_id))([inputs, x])
return x