Transfer learning on TensorFlow-Slim image classification model library
# Copyright 2016 The TensorFlow Authors. All Rights Reserved.## Licensed under the Apache License, Version 2.0 (the "License");# you may not use this file except in compliance with the License.# You may obtain a copy of the License at## http://www.apache.org/licenses/LICENSE-2.0## Unless required by applicable law or agreed to in writing, software# distributed under the License is distributed on an "AS IS" BASIS,# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.# See the License for the specific language governing permissions and# limitations under the License.# =============================================================================="""Contains the definition of the Inception Resnet V2 architecture.As described in http://arxiv.org/abs/1602.07261. Inception-v4, Inception-ResNet and the Impact of Residual Connections on Learning Christian Szegedy, Sergey Ioffe, Vincent Vanhoucke, Alex Alemi"""from __future__ import absolute_importfrom __future__ import divisionfrom __future__ import print_functionimport tensorflow.compat.v1 as tfimport tf_slim as slimdef block35(net, scale=1.0, activation_fn=tf.nn.relu, scope=None, reuse=None): """Builds the 35x35 resnet block.""" with tf.variable_scope(scope, 'Block35', [net], reuse=reuse): with tf.variable_scope('Branch_0'): tower_conv = slim.conv2d(net, 32, 1, scope='Conv2d_1x1') with tf.variable_scope('Branch_1'): tower_conv1_0 = slim.conv2d(net, 32, 1, scope='Conv2d_0a_1x1') tower_conv1_1 = slim.conv2d(tower_conv1_0, 32, 3, scope='Conv2d_0b_3x3') with tf.variable_scope('Branch_2'): tower_conv2_0 = slim.conv2d(net, 32, 1, scope='Conv2d_0a_1x1') tower_conv2_1 = slim.conv2d(tower_conv2_0, 48, 3, scope='Conv2d_0b_3x3') tower_conv2_2 = slim.conv2d(tower_conv2_1, 64, 3, scope='Conv2d_0c_3x3') mixed = tf.concat(axis=3, values=[tower_conv, tower_conv1_1, tower_conv2_2]) up = slim.conv2d(mixed, net.get_shape()[3], 1, normalizer_fn=None, activation_fn=None, scope='Conv2d_1x1') scaled_up = up * scale if activation_fn == tf.nn.relu6: # Use clip_by_value to simulate bandpass activation. scaled_up = tf.clip_by_value(scaled_up, -6.0, 6.0) net += scaled_up if activation_fn: net = activation_fn(net) return netdef block17(net, scale=1.0, activation_fn=tf.nn.relu, scope=None, reuse=None): """Builds the 17x17 resnet block.""" with tf.variable_scope(scope, 'Block17', [net], reuse=reuse): with tf.variable_scope('Branch_0'): tower_conv = slim.conv2d(net, 192, 1, scope='Conv2d_1x1') with tf.variable_scope('Branch_1'): tower_conv1_0 = slim.conv2d(net, 128, 1, scope='Conv2d_0a_1x1') tower_conv1_1 = slim.conv2d(tower_conv1_0, 160, [1, 7], scope='Conv2d_0b_1x7') tower_conv1_2 = slim.conv2d(tower_conv1_1, 192, [7, 1], scope='Conv2d_0c_7x1') mixed = tf.concat(axis=3, values=[tower_conv, tower_conv1_2]) up = slim.conv2d(mixed, net.get_shape()[3], 1, normalizer_fn=None, activation_fn=None, scope='Conv2d_1x1') scaled_up = up * scale if activation_fn == tf.nn.relu6: # Use clip_by_value to simulate bandpass activation. scaled_up = tf.clip_by_value(scaled_up, -6.0, 6.0) net += scaled_up if activation_fn: net = activation_fn(net) return netdef block8(net, scale=1.0, activation_fn=tf.nn.relu, scope=None, reuse=None): """Builds the 8x8 resnet block.""" with tf.variable_scope(scope, 'Block8', [net], reuse=reuse): with tf.variable_scope('Branch_0'): tower_conv = slim.conv2d(net, 192, 1, scope='Conv2d_1x1') with tf.variable_scope('Branch_1'): tower_conv1_0 = slim.conv2d(net, 192, 1, scope='Conv2d_0a_1x1') tower_conv1_1 = slim.conv2d(tower_conv1_0, 224, [1, 3], scope='Conv2d_0b_1x3') tower_conv1_2 = slim.conv2d(tower_conv1_1, 256, [3, 1], scope='Conv2d_0c_3x1') mixed = tf.concat(axis=3, values=[tower_conv, tower_conv1_2]) up = slim.conv2d(mixed, net.get_shape()[3], 1, normalizer_fn=None, activation_fn=None, scope='Conv2d_1x1') scaled_up = up * scale if activation_fn == tf.nn.relu6: # Use clip_by_value to simulate bandpass activation. scaled_up = tf.clip_by_value(scaled_up, -6.0, 6.0) net += scaled_up if activation_fn: net = activation_fn(net) return netdef inception_resnet_v2_base(inputs, final_endpoint='Conv2d_7b_1x1', output_stride=16, align_feature_maps=False, scope=None, activation_fn=tf.nn.relu): """Inception model from http://arxiv.org/abs/1602.07261. Constructs an Inception Resnet v2 network from inputs to the given final endpoint. This method can construct the network up to the final inception block Conv2d_7b_1x1. Args: inputs: a tensor of size [batch_size, height, width, channels]. final_endpoint: specifies the endpoint to construct the network up to. It can be one of ['Conv2d_1a_3x3', 'Conv2d_2a_3x3', 'Conv2d_2b_3x3', 'MaxPool_3a_3x3', 'Conv2d_3b_1x1', 'Conv2d_4a_3x3', 'MaxPool_5a_3x3', 'Mixed_5b', 'Mixed_6a', 'PreAuxLogits', 'Mixed_7a', 'Conv2d_7b_1x1'] output_stride: A scalar that specifies the requested ratio of input to output spatial resolution. Only supports 8 and 16. align_feature_maps: When true, changes all the VALID paddings in the network to SAME padding so that the feature maps are aligned. scope: Optional variable_scope. activation_fn: Activation function for block scopes. Returns: tensor_out: output tensor corresponding to the final_endpoint. end_points: a set of activations for external use, for example summaries or losses. Raises: ValueError: if final_endpoint is not set to one of the predefined values, or if the output_stride is not 8 or 16, or if the output_stride is 8 and we request an end point after 'PreAuxLogits'. """ if output_stride != 8 and output_stride != 16: raise ValueError('output_stride must be 8 or 16.') padding = 'SAME' if align_feature_maps else 'VALID' end_points = {} def add_and_check_final(name, net): end_points[name] = net return name == final_endpoint with tf.variable_scope(scope, 'InceptionResnetV2', [inputs]): with slim.arg_scope([slim.conv2d, slim.max_pool2d, slim.avg_pool2d], stride=1, padding='SAME'): # 149 x 149 x 32 net = slim.conv2d(inputs, 32, 3, stride=2, padding=padding, scope='Conv2d_1a_3x3') if add_and_check_final('Conv2d_1a_3x3', net): return net, end_points # 147 x 147 x 32 net = slim.conv2d(net, 32, 3, padding=padding, scope='Conv2d_2a_3x3') if add_and_check_final('Conv2d_2a_3x3', net): return net, end_points # 147 x 147 x 64 net = slim.conv2d(net, 64, 3, scope='Conv2d_2b_3x3') if add_and_check_final('Conv2d_2b_3x3', net): return net, end_points # 73 x 73 x 64 net = slim.max_pool2d(net, 3, stride=2, padding=padding, scope='MaxPool_3a_3x3') if add_and_check_final('MaxPool_3a_3x3', net): return net, end_points # 73 x 73 x 80 net = slim.conv2d(net, 80, 1, padding=padding, scope='Conv2d_3b_1x1') if add_and_check_final('Conv2d_3b_1x1', net): return net, end_points # 71 x 71 x 192 net = slim.conv2d(net, 192, 3, padding=padding, scope='Conv2d_4a_3x3') if add_and_check_final('Conv2d_4a_3x3', net): return net, end_points # 35 x 35 x 192 net = slim.max_pool2d(net, 3, stride=2, padding=padding, scope='MaxPool_5a_3x3') if add_and_check_final('MaxPool_5a_3x3', net): return net, end_points # 35 x 35 x 320 with tf.variable_scope('Mixed_5b'): with tf.variable_scope('Branch_0'): tower_conv = slim.conv2d(net, 96, 1, scope='Conv2d_1x1') with tf.variable_scope('Branch_1'): tower_conv1_0 = slim.conv2d(net, 48, 1, scope='Conv2d_0a_1x1') tower_conv1_1 = slim.conv2d(tower_conv1_0, 64, 5, scope='Conv2d_0b_5x5') with tf.variable_scope('Branch_2'): tower_conv2_0 = slim.conv2d(net, 64, 1, scope='Conv2d_0a_1x1') tower_conv2_1 = slim.conv2d(tower_conv2_0, 96, 3, scope='Conv2d_0b_3x3') tower_conv2_2 = slim.conv2d(tower_conv2_1, 96, 3, scope='Conv2d_0c_3x3') with tf.variable_scope('Branch_3'): tower_pool = slim.avg_pool2d(net, 3, stride=1, padding='SAME', scope='AvgPool_0a_3x3') tower_pool_1 = slim.conv2d(tower_pool, 64, 1, scope='Conv2d_0b_1x1') net = tf.concat( [tower_conv, tower_conv1_1, tower_conv2_2, tower_pool_1], 3) if add_and_check_final('Mixed_5b', net): return net, end_points # TODO(alemi): Register intermediate endpoints net = slim.repeat(net, 10, block35, scale=0.17, activation_fn=activation_fn) # 17 x 17 x 1088 if output_stride == 8, # 33 x 33 x 1088 if output_stride == 16 use_atrous = output_stride == 8 with tf.variable_scope('Mixed_6a'): with tf.variable_scope('Branch_0'): tower_conv = slim.conv2d(net, 384, 3, stride=1 if use_atrous else 2, padding=padding, scope='Conv2d_1a_3x3') with tf.variable_scope('Branch_1'): tower_conv1_0 = slim.conv2d(net, 256, 1, scope='Conv2d_0a_1x1') tower_conv1_1 = slim.conv2d(tower_conv1_0, 256, 3, scope='Conv2d_0b_3x3') tower_conv1_2 = slim.conv2d(tower_conv1_1, 384, 3, stride=1 if use_atrous else 2, padding=padding, scope='Conv2d_1a_3x3') with tf.variable_scope('Branch_2'): tower_pool = slim.max_pool2d(net, 3, stride=1 if use_atrous else 2, padding=padding, scope='MaxPool_1a_3x3') net = tf.concat([tower_conv, tower_conv1_2, tower_pool], 3) if add_and_check_final('Mixed_6a', net): return net, end_points # TODO(alemi): register intermediate endpoints with slim.arg_scope([slim.conv2d], rate=2 if use_atrous else 1): net = slim.repeat(net, 20, block17, scale=0.10, activation_fn=activation_fn) if add_and_check_final('PreAuxLogits', net): return net, end_points if output_stride == 8: # TODO(gpapan): Properly support output_stride for the rest of the net. raise ValueError('output_stride==8 is only supported up to the ' 'PreAuxlogits end_point for now.') # 8 x 8 x 2080 with tf.variable_scope('Mixed_7a'): with tf.variable_scope('Branch_0'): tower_conv = slim.conv2d(net, 256, 1, scope='Conv2d_0a_1x1') tower_conv_1 = slim.conv2d(tower_conv, 384, 3, stride=2, padding=padding, scope='Conv2d_1a_3x3') with tf.variable_scope('Branch_1'): tower_conv1 = slim.conv2d(net, 256, 1, scope='Conv2d_0a_1x1') tower_conv1_1 = slim.conv2d(tower_conv1, 288, 3, stride=2, padding=padding, scope='Conv2d_1a_3x3') with tf.variable_scope('Branch_2'): tower_conv2 = slim.conv2d(net, 256, 1, scope='Conv2d_0a_1x1') tower_conv2_1 = slim.conv2d(tower_conv2, 288, 3, scope='Conv2d_0b_3x3') tower_conv2_2 = slim.conv2d(tower_conv2_1, 320, 3, stride=2, padding=padding, scope='Conv2d_1a_3x3') with tf.variable_scope('Branch_3'): tower_pool = slim.max_pool2d(net, 3, stride=2, padding=padding, scope='MaxPool_1a_3x3') net = tf.concat( [tower_conv_1, tower_conv1_1, tower_conv2_2, tower_pool], 3) if add_and_check_final('Mixed_7a', net): return net, end_points # TODO(alemi): register intermediate endpoints net = slim.repeat(net, 9, block8, scale=0.20, activation_fn=activation_fn) net = block8(net, activation_fn=None) # 8 x 8 x 1536 net = slim.conv2d(net, 1536, 1, scope='Conv2d_7b_1x1') if add_and_check_final('Conv2d_7b_1x1', net): return net, end_points raise ValueError('final_endpoint (%s) not recognized', final_endpoint)def inception_resnet_v2(inputs, num_classes=1001, is_training=True, dropout_keep_prob=0.8, reuse=None, scope='InceptionResnetV2', create_aux_logits=True, activation_fn=tf.nn.relu): """Creates the Inception Resnet V2 model. Args: inputs: a 4-D tensor of size [batch_size, height, width, 3]. Dimension batch_size may be undefined. If create_aux_logits is false, also height and width may be undefined. num_classes: number of predicted classes. If 0 or None, the logits layer is omitted and the input features to the logits layer (before dropout) are returned instead. is_training: whether is training or not. dropout_keep_prob: float, the fraction to keep before final layer. reuse: whether or not the network and its variables should be reused. To be able to reuse 'scope' must be given. scope: Optional variable_scope. create_aux_logits: Whether to include the auxilliary logits. activation_fn: Activation function for conv2d. Returns: net: the output of the logits layer (if num_classes is a non-zero integer), or the non-dropped-out input to the logits layer (if num_classes is 0 or None). end_points: the set of end_points from the inception model. """ end_points = {} with tf.variable_scope( scope, 'InceptionResnetV2', [inputs], reuse=reuse) as scope: with slim.arg_scope([slim.batch_norm, slim.dropout], is_training=is_training): net, end_points = inception_resnet_v2_base(inputs, scope=scope, activation_fn=activation_fn) if create_aux_logits and num_classes: with tf.variable_scope('AuxLogits'): aux = end_points['PreAuxLogits'] aux = slim.avg_pool2d(aux, 5, stride=3, padding='VALID', scope='Conv2d_1a_3x3') aux = slim.conv2d(aux, 128, 1, scope='Conv2d_1b_1x1') aux = slim.conv2d(aux, 768, aux.get_shape()[1:3], padding='VALID', scope='Conv2d_2a_5x5') aux = slim.flatten(aux) aux = slim.fully_connected(aux, num_classes, activation_fn=None, scope='Logits') end_points['AuxLogits'] = aux with tf.variable_scope('Logits'): # TODO(sguada,arnoegw): Consider adding a parameter global_pool which # can be set to False to disable pooling here (as in resnet_*()). kernel_size = net.get_shape()[1:3] if kernel_size.is_fully_defined(): net = slim.avg_pool2d(net, kernel_size, padding='VALID', scope='AvgPool_1a_8x8') else: net = tf.reduce_mean( input_tensor=net, axis=[1, 2], keepdims=True, name='global_pool') end_points['global_pool'] = net if not num_classes: return net, end_points net = slim.flatten(net) net = slim.dropout(net, dropout_keep_prob, is_training=is_training, scope='Dropout') end_points['PreLogitsFlatten'] = net logits = slim.fully_connected(net, num_classes, activation_fn=None, scope='Logits') end_points['Logits'] = logits end_points['Predictions'] = tf.nn.softmax(logits, name='Predictions') return logits, end_pointsinception_resnet_v2.default_image_size = 299def inception_resnet_v2_arg_scope( weight_decay=0.00004, batch_norm_decay=0.9997, batch_norm_epsilon=0.001, activation_fn=tf.nn.relu, batch_norm_updates_collections=tf.GraphKeys.UPDATE_OPS, batch_norm_scale=False): """Returns the scope with the default parameters for inception_resnet_v2. Args: weight_decay: the weight decay for weights variables. batch_norm_decay: decay for the moving average of batch_norm momentums. batch_norm_epsilon: small float added to variance to avoid dividing by zero. activation_fn: Activation function for conv2d. batch_norm_updates_collections: Collection for the update ops for batch norm. batch_norm_scale: If True, uses an explicit `gamma` multiplier to scale the activations in the batch normalization layer. Returns: a arg_scope with the parameters needed for inception_resnet_v2. """ # Set weight_decay for weights in conv2d and fully_connected layers. with slim.arg_scope([slim.conv2d, slim.fully_connected], weights_regularizer=slim.l2_regularizer(weight_decay), biases_regularizer=slim.l2_regularizer(weight_decay)): batch_norm_params = { 'decay': batch_norm_decay, 'epsilon': batch_norm_epsilon, 'updates_collections': batch_norm_updates_collections, 'fused': None, # Use fused batch norm if possible. 'scale': batch_norm_scale, } # Set activation_fn and parameters for batch_norm. with slim.arg_scope([slim.conv2d], activation_fn=activation_fn, normalizer_fn=slim.batch_norm, normalizer_params=batch_norm_params) as scope: return scope