python深度学习tensorflow卷积层示例教程
作者:denny402
一、旧版本(1.0以下)的卷积函数:tf.nn.conv2d
在tf1.0中,对卷积层重新进行了封装,比原来版本的卷积层有了很大的简化。
conv2d( input, filter, strides, padding, use_cudnn_on_gpu=None, data_format=None, name=None )
该函数定义在tensorflow/python/ops/gen_nn_ops.py。
参数:
input
: 一个4维Tensor(N,H,W,C). 类型必须是以下几种类型之一: half
, float32
, float64
.
filter
: 卷积核. 类型和input
必须相同,
4维tensor, [filter_height, filter_width, in_channels, out_channels],如[5,5,3,32]
strides
: 在input
上切片采样时,每个方向上的滑窗步长,必须和format指定的维度同阶,如[1, 2, 2, 1]
padding
: 指定边缘填充类型: "SAME", "VALID". SAME表示卷积后图片保持不变,VALID则会缩小。
use_cudnn_on_gpu
: 可选项,bool型。表示是否在GPU上用cudnn进行加速,默认为True.
data_format
: 可选项,指定输入数据的格式: "NHWC"或 "NCHW", 默认为"NHWC"。
NHWC格式指[batch, in_height, in_width, in_channels]NCHW格式指[batch, in_channels, in_height, in_width]
name
: 操作名,可选.
示例
conv1=tf.nn.conv2d(x, W, strides=[1, 1, 1, 1], padding='SAME')
二、1.0版本中的卷积函数:tf.layers.conv2d
conv2d( inputs, filters, kernel_size, strides=(1, 1), padding='valid', data_format='channels_last', dilation_rate=(1, 1), activation=None, use_bias=True, kernel_initializer=None, bias_initializer=tf.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, reuse=None )
定义
# Copyright 2015 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. # ============================================================================= # pylint: disable=unused-import,g-bad-import-order """Contains the convolutional layer classes and their functional aliases. """ from __future__ import absolute_import from __future__ import division from __future__ import print_function import six from six.moves import xrange # pylint: disable=redefined-builtin import numpy as np from tensorflow.python.framework import ops from tensorflow.python.ops import array_ops from tensorflow.python.ops import control_flow_ops from tensorflow.python.ops import nn from tensorflow.python.ops import math_ops from tensorflow.python.ops import init_ops from tensorflow.python.ops import standard_ops from tensorflow.python.ops import variable_scope as vs from tensorflow.python.layers import base from tensorflow.python.layers import utils class _Conv(base._Layer): # pylint: disable=protected-access """Abstract nD convolution layer (private, used as implementation base). This layer creates a convolution kernel that is convolved (actually cross-correlated) with the layer input to produce a tensor of outputs. If `use_bias` is True (and a `bias_initializer` is provided), a bias vector is created and added to the outputs. Finally, if `activation` is not `None`, it is applied to the outputs as well. Arguments: rank: An integer, the rank of the convolution, e.g. "2" for 2D convolution. filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: An integer or tuple/list of n integers, specifying the length of the convolution window. strides: An integer or tuple/list of n integers, specifying the stride length of the convolution. Specifying any stride value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, ..., channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, ...)`. dilation_rate: An integer or tuple/list of n integers, specifying the dilation rate to use for dilated convolution. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any `strides` value != 1. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. """ def __init__(self, rank, filters, kernel_size, strides=1, padding='valid', data_format='channels_last', dilation_rate=1, activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, **kwargs): super(_Conv, self).__init__(trainable=trainable, name=name, **kwargs) self.rank = rank self.filters = filters self.kernel_size = utils.normalize_tuple(kernel_size, rank, 'kernel_size') self.strides = utils.normalize_tuple(strides, rank, 'strides') self.padding = utils.normalize_padding(padding) self.data_format = utils.normalize_data_format(data_format) self.dilation_rate = utils.normalize_tuple( dilation_rate, rank, 'dilation_rate') self.activation = activation self.use_bias = use_bias self.kernel_initializer = kernel_initializer self.bias_initializer = bias_initializer self.kernel_regularizer = kernel_regularizer self.bias_regularizer = bias_regularizer self.activity_regularizer = activity_regularizer def build(self, input_shape): if len(input_shape) != self.rank + 2: raise ValueError('Inputs should have rank ' + str(self.rank + 2) + 'Received input shape:', str(input_shape)) if self.data_format == 'channels_first': channel_axis = 1 else: channel_axis = -1 if input_shape[channel_axis] is None: raise ValueError('The channel dimension of the inputs ' 'should be defined. Found `None`.') input_dim = input_shape[channel_axis] kernel_shape = self.kernel_size + (input_dim, self.filters) self.kernel = vs.get_variable('kernel', shape=kernel_shape, initializer=self.kernel_initializer, regularizer=self.kernel_regularizer, trainable=True, dtype=self.dtype) if self.use_bias: self.bias = vs.get_variable('bias', shape=(self.filters,), initializer=self.bias_initializer, regularizer=self.bias_regularizer, trainable=True, dtype=self.dtype) else: self.bias = None def call(self, inputs): outputs = nn.convolution( input=inputs, filter=self.kernel, dilation_rate=self.dilation_rate, strides=self.strides, padding=self.padding.upper(), data_format=utils.convert_data_format(self.data_format, self.rank + 2)) if self.bias is not None: if self.rank != 2 and self.data_format == 'channels_first': # bias_add does not support channels_first for non-4D inputs. if self.rank == 1: bias = array_ops.reshape(self.bias, (1, self.filters, 1)) if self.rank == 3: bias = array_ops.reshape(self.bias, (1, self.filters, 1, 1)) outputs += bias else: outputs = nn.bias_add( outputs, self.bias, data_format=utils.convert_data_format(self.data_format, 4)) # Note that we passed rank=4 because bias_add will only accept # NHWC and NCWH even if the rank of the inputs is 3 or 5. if self.activation is not None: return self.activation(outputs) return outputs class Conv1D(_Conv): """1D convolution layer (e.g. temporal convolution). This layer creates a convolution kernel that is convolved (actually cross-correlated) with the layer input to produce a tensor of outputs. If `use_bias` is True (and a `bias_initializer` is provided), a bias vector is created and added to the outputs. Finally, if `activation` is not `None`, it is applied to the outputs as well. Arguments: filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: An integer or tuple/list of a single integer, specifying the length of the 1D convolution window. strides: An integer or tuple/list of a single integer, specifying the stride length of the convolution. Specifying any stride value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, length, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, length)`. dilation_rate: An integer or tuple/list of a single integer, specifying the dilation rate to use for dilated convolution. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any `strides` value != 1. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. """ def __init__(self, filters, kernel_size, strides=1, padding='valid', data_format='channels_last', dilation_rate=1, activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, **kwargs): super(Convolution1D, self).__init__( rank=1, filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, **kwargs) def conv1d(inputs, filters, kernel_size, strides=1, padding='valid', data_format='channels_last', dilation_rate=1, activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, reuse=None): """Functional interface for 1D convolution layer (e.g. temporal convolution). This layer creates a convolution kernel that is convolved (actually cross-correlated) with the layer input to produce a tensor of outputs. If `use_bias` is True (and a `bias_initializer` is provided), a bias vector is created and added to the outputs. Finally, if `activation` is not `None`, it is applied to the outputs as well. Arguments: inputs: Tensor input. filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: An integer or tuple/list of a single integer, specifying the length of the 1D convolution window. strides: An integer or tuple/list of a single integer, specifying the stride length of the convolution. Specifying any stride value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, length, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, length)`. dilation_rate: An integer or tuple/list of a single integer, specifying the dilation rate to use for dilated convolution. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any `strides` value != 1. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. reuse: Boolean, whether to reuse the weights of a previous layer by the same name. Returns: Output tensor. """ layer = Conv1D( filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, _reuse=reuse, _scope=name) return layer.apply(inputs) class Conv2D(_Conv): """2D convolution layer (e.g. spatial convolution over images). This layer creates a convolution kernel that is convolved (actually cross-correlated) with the layer input to produce a tensor of outputs. If `use_bias` is True (and a `bias_initializer` is provided), a bias vector is created and added to the outputs. Finally, if `activation` is not `None`, it is applied to the outputs as well. Arguments: filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: An integer or tuple/list of 2 integers, specifying the width and height of the 2D convolution window. Can be a single integer to specify the same value for all spatial dimensions. strides: An integer or tuple/list of 2 integers, specifying the strides of the convolution along the height and width. Can be a single integer to specify the same value for all spatial dimensions. Specifying any stride value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, height, width)`. dilation_rate: An integer or tuple/list of 2 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any stride value != 1. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. """ def __init__(self, filters, kernel_size, strides=(1, 1), padding='valid', data_format='channels_last', dilation_rate=(1, 1), activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, **kwargs): super(Conv2D, self).__init__( rank=2, filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, **kwargs) def conv2d(inputs, filters, kernel_size, strides=(1, 1), padding='valid', data_format='channels_last', dilation_rate=(1, 1), activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, reuse=None): """Functional interface for the 2D convolution layer. This layer creates a convolution kernel that is convolved (actually cross-correlated) with the layer input to produce a tensor of outputs. If `use_bias` is True (and a `bias_initializer` is provided), a bias vector is created and added to the outputs. Finally, if `activation` is not `None`, it is applied to the outputs as well. Arguments: inputs: Tensor input. filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: An integer or tuple/list of 2 integers, specifying the width and height of the 2D convolution window. Can be a single integer to specify the same value for all spatial dimensions. strides: An integer or tuple/list of 2 integers, specifying the strides of the convolution along the height and width. Can be a single integer to specify the same value for all spatial dimensions. Specifying any stride value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, height, width)`. dilation_rate: An integer or tuple/list of 2 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any stride value != 1. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. reuse: Boolean, whether to reuse the weights of a previous layer by the same name. Returns: Output tensor. """ layer = Conv2D( filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, _reuse=reuse, _scope=name) return layer.apply(inputs) class Conv3D(_Conv): """3D convolution layer (e.g. spatial convolution over volumes). This layer creates a convolution kernel that is convolved (actually cross-correlated) with the layer input to produce a tensor of outputs. If `use_bias` is True (and a `bias_initializer` is provided), a bias vector is created and added to the outputs. Finally, if `activation` is not `None`, it is applied to the outputs as well. Arguments: filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: An integer or tuple/list of 3 integers, specifying the depth, height and width of the 3D convolution window. Can be a single integer to specify the same value for all spatial dimensions. strides: An integer or tuple/list of 3 integers, specifying the strides of the convolution along the depth, height and width. Can be a single integer to specify the same value for all spatial dimensions. Specifying any stride value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, depth, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, depth, height, width)`. dilation_rate: An integer or tuple/list of 3 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any stride value != 1. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. """ def __init__(self, filters, kernel_size, strides=(1, 1, 1), padding='valid', data_format='channels_last', dilation_rate=(1, 1, 1), activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, **kwargs): super(Conv3D, self).__init__( rank=3, filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, **kwargs) def conv3d(inputs, filters, kernel_size, strides=(1, 1, 1), padding='valid', data_format='channels_last', dilation_rate=(1, 1, 1), activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, reuse=None): """Functional interface for the 3D convolution layer. This layer creates a convolution kernel that is convolved (actually cross-correlated) with the layer input to produce a tensor of outputs. If `use_bias` is True (and a `bias_initializer` is provided), a bias vector is created and added to the outputs. Finally, if `activation` is not `None`, it is applied to the outputs as well. Arguments: inputs: Tensor input. filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: An integer or tuple/list of 3 integers, specifying the depth, height and width of the 3D convolution window. Can be a single integer to specify the same value for all spatial dimensions. strides: An integer or tuple/list of 3 integers, specifying the strides of the convolution along the depth, height and width. Can be a single integer to specify the same value for all spatial dimensions. Specifying any stride value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, depth, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, depth, height, width)`. dilation_rate: An integer or tuple/list of 3 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any stride value != 1. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. reuse: Boolean, whether to reuse the weights of a previous layer by the same name. Returns: Output tensor. """ layer = Conv3D( filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, _reuse=reuse, _scope=name) return layer.apply(inputs) class SeparableConv2D(Conv2D): """Depthwise separable 2D convolution. This layer performs a depthwise convolution that acts separately on channels, followed by a pointwise convolution that mixes channels. If `use_bias` is True and a bias initializer is provided, it adds a bias vector to the output. It then optionally applies an activation function to produce the final output. Arguments: filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: A tuple or list of 2 integers specifying the spatial dimensions of of the filters. Can be a single integer to specify the same value for all spatial dimensions. strides: A tuple or list of 2 positive integers specifying the strides of the convolution. Can be a single integer to specify the same value for all spatial dimensions. Specifying any `stride` value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, height, width)`. dilation_rate: An integer or tuple/list of 2 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any stride value != 1. depth_multiplier: The number of depthwise convolution output channels for each input channel. The total number of depthwise convolution output channels will be equal to `num_filters_in * depth_multiplier`. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. depthwise_initializer: An initializer for the depthwise convolution kernel. pointwise_initializer: An initializer for the pointwise convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. depthwise_regularizer: Optional regularizer for the depthwise convolution kernel. pointwise_regularizer: Optional regularizer for the pointwise convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. """ def __init__(self, filters, kernel_size, strides=(1, 1), padding='valid', data_format='channels_last', dilation_rate=(1, 1), depth_multiplier=1, activation=None, use_bias=True, depthwise_initializer=None, pointwise_initializer=None, bias_initializer=init_ops.zeros_initializer(), depthwise_regularizer=None, pointwise_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, **kwargs): super(SeparableConv2D, self).__init__( filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, activation=activation, use_bias=use_bias, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, **kwargs) self.depth_multiplier = depth_multiplier self.depthwise_initializer = depthwise_initializer self.pointwise_initializer = pointwise_initializer self.depthwise_regularizer = depthwise_regularizer self.pointwise_regularizer = pointwise_regularizer def build(self, input_shape): if len(input_shape) < 4: raise ValueError('Inputs to `SeparableConv2D` should have rank 4. ' 'Received input shape:', str(input_shape)) if self.data_format == 'channels_first': channel_axis = 1 else: channel_axis = 3 if input_shape[channel_axis] is None: raise ValueError('The channel dimension of the inputs to ' '`SeparableConv2D` ' 'should be defined. Found `None`.') input_dim = int(input_shape[channel_axis]) depthwise_kernel_shape = (self.kernel_size[0], self.kernel_size[1], input_dim, self.depth_multiplier) pointwise_kernel_shape = (1, 1, self.depth_multiplier * input_dim, self.filters) self.depthwise_kernel = vs.get_variable( 'depthwise_kernel', shape=depthwise_kernel_shape, initializer=self.depthwise_initializer, regularizer=self.depthwise_regularizer, trainable=True, dtype=self.dtype) self.pointwise_kernel = vs.get_variable( 'pointwise_kernel', shape=pointwise_kernel_shape, initializer=self.pointwise_initializer, regularizer=self.pointwise_regularizer, trainable=True, dtype=self.dtype) if self.use_bias: self.bias = vs.get_variable('bias', shape=(self.filters,), initializer=self.bias_initializer, regularizer=self.bias_regularizer, trainable=True, dtype=self.dtype) else: self.bias = None def call(self, inputs): if self.data_format == 'channels_first': # Reshape to channels last inputs = array_ops.transpose(inputs, (0, 2, 3, 1)) # Apply the actual ops. outputs = nn.separable_conv2d( inputs, self.depthwise_kernel, self.pointwise_kernel, strides=(1,) + self.strides + (1,), padding=self.padding.upper(), rate=self.dilation_rate) if self.data_format == 'channels_first': # Reshape to channels first outputs = array_ops.transpose(outputs, (0, 3, 1, 2)) if self.bias is not None: outputs = nn.bias_add( outputs, self.bias, data_format=utils.convert_data_format(self.data_format, ndim=4)) if self.activation is not None: return self.activation(outputs) return outputs def separable_conv2d(inputs, filters, kernel_size, strides=(1, 1), padding='valid', data_format='channels_last', dilation_rate=(1, 1), depth_multiplier=1, activation=None, use_bias=True, depthwise_initializer=None, pointwise_initializer=None, bias_initializer=init_ops.zeros_initializer(), depthwise_regularizer=None, pointwise_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, reuse=None): """Functional interface for the depthwise separable 2D convolution layer. This layer performs a depthwise convolution that acts separately on channels, followed by a pointwise convolution that mixes channels. If `use_bias` is True and a bias initializer is provided, it adds a bias vector to the output. It then optionally applies an activation function to produce the final output. Arguments: inputs: Input tensor. filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: A tuple or list of 2 integers specifying the spatial dimensions of of the filters. Can be a single integer to specify the same value for all spatial dimensions. strides: A tuple or list of 2 positive integers specifying the strides of the convolution. Can be a single integer to specify the same value for all spatial dimensions. Specifying any `stride` value != 1 is incompatible with specifying any `dilation_rate` value != 1. padding: One of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, height, width)`. dilation_rate: An integer or tuple/list of 2 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any `dilation_rate` value != 1 is incompatible with specifying any stride value != 1. depth_multiplier: The number of depthwise convolution output channels for each input channel. The total number of depthwise convolution output channels will be equal to `num_filters_in * depth_multiplier`. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. depthwise_initializer: An initializer for the depthwise convolution kernel. pointwise_initializer: An initializer for the pointwise convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. depthwise_regularizer: Optional regularizer for the depthwise convolution kernel. pointwise_regularizer: Optional regularizer for the pointwise convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. reuse: Boolean, whether to reuse the weights of a previous layer by the same name. Returns: Output tensor. """ layer = SeparableConv2D( filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, dilation_rate=dilation_rate, depth_multiplier=depth_multiplier, activation=activation, use_bias=use_bias, depthwise_initializer=depthwise_initializer, pointwise_initializer=pointwise_initializer, bias_initializer=bias_initializer, depthwise_regularizer=depthwise_regularizer, pointwise_regularizer=pointwise_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, _reuse=reuse, _scope=name) return layer.apply(inputs) class Conv2DTranspose(Conv2D): """Transposed convolution layer (sometimes called Deconvolution). The need for transposed convolutions generally arises from the desire to use a transformation going in the opposite direction of a normal convolution, i.e., from something that has the shape of the output of some convolution to something that has the shape of its input while maintaining a connectivity pattern that is compatible with said convolution. Arguments: filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: A tuple or list of 2 positive integers specifying the spatial dimensions of of the filters. Can be a single integer to specify the same value for all spatial dimensions. strides: A tuple or list of 2 positive integers specifying the strides of the convolution. Can be a single integer to specify the same value for all spatial dimensions. padding: one of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, height, width)`. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. """ def __init__(self, filters, kernel_size, strides=(1, 1), padding='valid', data_format='channels_last', activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, **kwargs): super(Conv2DTranspose, self).__init__( filters, kernel_size, strides=strides, padding=padding, data_format=data_format, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, **kwargs) def build(self, input_shape): if len(input_shape) != 4: raise ValueError('Inputs should have rank ' + str(4) + 'Received input shape:', str(input_shape)) if self.data_format == 'channels_first': channel_axis = 1 else: channel_axis = -1 if input_shape[channel_axis] is None: raise ValueError('The channel dimension of the inputs ' 'should be defined. Found `None`.') input_dim = input_shape[channel_axis] kernel_shape = self.kernel_size + (self.filters, input_dim) self.kernel = vs.get_variable('kernel', shape=kernel_shape, initializer=self.kernel_initializer, regularizer=self.kernel_regularizer, trainable=True, dtype=self.dtype) if self.use_bias: self.bias = vs.get_variable('bias', shape=(self.filters,), initializer=self.bias_initializer, regularizer=self.bias_regularizer, trainable=True, dtype=self.dtype) else: self.bias = None def call(self, inputs): inputs_shape = array_ops.shape(inputs) batch_size = inputs_shape[0] if self.data_format == 'channels_first': c_axis, h_axis, w_axis = 1, 2, 3 else: c_axis, h_axis, w_axis = 3, 1, 2 height, width = inputs_shape[h_axis], inputs_shape[w_axis] kernel_h, kernel_w = self.kernel_size stride_h, stride_w = self.strides def get_deconv_dim(dim_size, stride_size, kernel_size, padding): if isinstance(dim_size, ops.Tensor): dim_size = math_ops.multiply(dim_size, stride_size) elif dim_size is not None: dim_size *= stride_size if padding == 'valid' and dim_size is not None: dim_size += max(kernel_size - stride_size, 0) return dim_size # Infer the dynamic output shape: out_height = get_deconv_dim(height, stride_h, kernel_h, self.padding) out_width = get_deconv_dim(width, stride_w, kernel_w, self.padding) if self.data_format == 'channels_first': output_shape = (batch_size, self.filters, out_height, out_width) strides = (1, 1, stride_h, stride_w) else: output_shape = (batch_size, out_height, out_width, self.filters) strides = (1, stride_h, stride_w, 1) output_shape_tensor = array_ops.stack(output_shape) outputs = nn.conv2d_transpose( inputs, self.kernel, output_shape_tensor, strides, padding=self.padding.upper(), data_format=utils.convert_data_format(self.data_format, ndim=4)) # Infer the static output shape: out_shape = inputs.get_shape().as_list() out_shape[c_axis] = self.filters out_shape[h_axis] = get_deconv_dim( out_shape[h_axis], stride_h, kernel_h, self.padding) out_shape[w_axis] = get_deconv_dim( out_shape[w_axis], stride_w, kernel_w, self.padding) outputs.set_shape(out_shape) if self.bias: outputs = nn.bias_add( outputs, self.bias, data_format=utils.convert_data_format(self.data_format, ndim=4)) if self.activation is not None: return self.activation(outputs) return outputs def conv2d_transpose(inputs, filters, kernel_size, strides=(1, 1), padding='valid', data_format='channels_last', activation=None, use_bias=True, kernel_initializer=None, bias_initializer=init_ops.zeros_initializer(), kernel_regularizer=None, bias_regularizer=None, activity_regularizer=None, trainable=True, name=None, reuse=None): """Transposed convolution layer (sometimes called Deconvolution). The need for transposed convolutions generally arises from the desire to use a transformation going in the opposite direction of a normal convolution, i.e., from something that has the shape of the output of some convolution to something that has the shape of its input while maintaining a connectivity pattern that is compatible with said convolution. Arguments: inputs: Input tensor. filters: Integer, the dimensionality of the output space (i.e. the number of filters in the convolution). kernel_size: A tuple or list of 2 positive integers specifying the spatial dimensions of of the filters. Can be a single integer to specify the same value for all spatial dimensions. strides: A tuple or list of 2 positive integers specifying the strides of the convolution. Can be a single integer to specify the same value for all spatial dimensions. padding: one of `"valid"` or `"same"` (case-insensitive). data_format: A string, one of `channels_last` (default) or `channels_first`. The ordering of the dimensions in the inputs. `channels_last` corresponds to inputs with shape `(batch, height, width, channels)` while `channels_first` corresponds to inputs with shape `(batch, channels, height, width)`. activation: Activation function. Set it to None to maintain a linear activation. use_bias: Boolean, whether the layer uses a bias. kernel_initializer: An initializer for the convolution kernel. bias_initializer: An initializer for the bias vector. If None, no bias will be applied. kernel_regularizer: Optional regularizer for the convolution kernel. bias_regularizer: Optional regularizer for the bias vector. activity_regularizer: Regularizer function for the output. trainable: Boolean, if `True` also add variables to the graph collection `GraphKeys.TRAINABLE_VARIABLES` (see `tf.Variable`). name: A string, the name of the layer. reuse: Boolean, whether to reuse the weights of a previous layer by the same name. Returns: Output tensor. """ layer = Conv2DTranspose( filters=filters, kernel_size=kernel_size, strides=strides, padding=padding, data_format=data_format, activation=activation, use_bias=use_bias, kernel_initializer=kernel_initializer, bias_initializer=bias_initializer, kernel_regularizer=kernel_regularizer, bias_regularizer=bias_regularizer, activity_regularizer=activity_regularizer, trainable=trainable, name=name, _reuse=reuse, _scope=name) return layer.apply(inputs) # Aliases Convolution1D = Conv1D Convolution2D = Conv2D Convolution3D = Conv3D SeparableConvolution2D = SeparableConv2D Convolution2DTranspose = Deconvolution2D = Deconv2D = Conv2DTranspose convolution1d = conv1d convolution2d = conv2d convolution3d = conv3d separable_convolution2d = separable_conv2d convolution2d_transpose = deconvolution2d = deconv2d = conv2d_transpose
参数:
参数多了很多,但实际用起来,却更简单。
inputs
: 输入数据,4维tensor.
filters
: 卷积核个数。
kernel_size
:卷积核大小,如【5,5】。如果长宽相等,也可以直接设置为一个数,如kernel_size=5
strides
: 卷积过程中的滑动步长,默认为[1,1]. 也可以直接设置为一个数,如strides=2
padding
: 边缘填充,'same' 和'valid‘选其一。默认为valid
data_format
: 输入数据格式,默认为channels_last ,
即 (batch, height, width, channels),也可以设置为channels_first 对应 (batch, channels, height, width).
dilation_rate
: 微步长卷积,这个比较复杂一些,请百度.
activation
: 激活函数.
use_bias
: Boolean型,是否使用偏置项.
kernel_initializer
: 卷积核的初始化器.
bias_initializer
: 偏置项的初始化器,默认初始化为0.
kernel_regularizer
: 卷积核化的正则化,可选.
bias_regularizer
: 偏置项的正则化,可选.
activity_regularizer
: 输出的正则化函数.
trainable
: Boolean型,表明该层的参数是否参与训练。
如果为真则变量加入到图集合中 GraphKeys.TRAINABLE_VARIABLES (see tf.Variable).
name
: 层的名字.
reuse
: Boolean型, 是否重复使用参数.
示例
conv1=tf.layers.conv2d( inputs=x, filters=32, kernel_size=5, padding="same", activation=tf.nn.relu, kernel_initializer=tf.TruncatedNormal(stddev=0.01))
更复杂一点的
conv1 = tf.layers.conv2d(batch_images, filters=64, kernel_size=7, strides=2, activation=tf.nn.relu, kernel_initializer=tf.TruncatedNormal(stddev=0.01) bias_initializer=tf.Constant(0.1), kernel_regularizer=tf.contrib.layers.l2_regularizer(0.003), bias_regularizer=tf.contrib.layers.l2_regularizer(0.003), name='conv1')
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