这篇文章主要讲解了“tensorflow卷积层如何理解，如何定义及参数有哪些”，文中的讲解内容简单、清晰、详细，对大家学习或是工作可能会有一定的帮助，希望大家阅读完这篇文章能有所收获。下面就请大家跟着小编的思路一起来学习一下吧。

目录

• 一、旧版本（1.0以下）的卷积函数：tf.nn.conv2d
• 参数：
• 二、1.0版本中的卷积函数:tf.layers.conv2d
• 定义
• 参数：
• 示例
• 更复杂一点的

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')

感谢各位的阅读，以上就是“tensorflow卷积层如何理解，如何定义及参数有哪些”的内容了，经过本文的学习后，相信大家对tensorflow卷积层如何理解，如何定义及参数有哪些都有更深刻的体会了吧。这里是群英网络，小编将为大家推送更多相关知识点的文章，欢迎关注！