python深度学习tensorflow卷积层示例教程

目录
  • 一、旧版本(1.0以下)的卷积函数:tf.nn.conv2d
  • 二、1.0版本中的卷积函数:tf.layers.conv2d

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: halffloat32float64.
  • 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')

以上就是python深度学习tensorflow卷积层示例教程的详细内容,更多关于python tensorflow卷积层的资料请关注我们其它相关文章!

(0)

相关推荐

  • python神经网络tensorflow利用训练好的模型进行预测

    目录 学习前言 载入模型思路 实现代码 学习前言 在神经网络学习中slim常用函数与如何训练.保存模型文章里已经讲述了如何使用slim训练出来一个模型,这篇文章将会讲述如何预测. 载入模型思路 载入模型的过程主要分为以下四步: 1.建立会话Session: 2.将img_input的placeholder传入网络,建立网络结构: 3.初始化所有变量: 4.利用saver对象restore载入所有参数. 这里要注意的重点是,在利用saver对象restore载入所有参数之前,必须要建立网络结构,因

  • python神经网络使用tensorflow构建长短时记忆LSTM

    目录 LSTM简介 1.RNN的梯度消失问题 2.LSTM的结构 tensorflow中LSTM的相关函数 tf.contrib.rnn.BasicLSTMCell tf.nn.dynamic_rnn 全部代码 LSTM简介 1.RNN的梯度消失问题 在过去的时间里我们学习了RNN循环神经网络,其结构示意图是这样的: 其存在的最大问题是,当w1.w2.w3这些值小于0时,如果一句话够长,那么其在神经网络进行反向传播与前向传播时,存在梯度消失的问题. 0.925=0.07,如果一句话有20到30个

  • python人工智能tensorflow构建卷积神经网络CNN

    目录 简介 隐含层介绍 1.卷积层 2.池化层 3.全连接层 具体实现代码 卷积层.池化层与全连接层实现代码 全部代码 学习神经网络已经有一段时间,从普通的BP神经网络到LSTM长短期记忆网络都有一定的了解,但是从未系统的把整个神经网络的结构记录下来,我相信这些小记录可以帮助我更加深刻的理解神经网络. 简介 卷积神经网络(Convolutional Neural Networks, CNN)是一类包含卷积计算且具有深度结构的前馈神经网络(Feedforward Neural Networks),

  • Python3.8安装tensorflow的简单方法步骤

    目录 以下内容是针对安装tensorflow-CPU版本的. 1.打开Anaconda promote 2.创建tensorflow的虚拟环境. 3.激活新建的TensorFlow环境,在命令行输入 4.使用国内的镜像安装,这里选用的是清华的镜像. 5.测试安装是否成功 总结 以下内容是针对安装tensorflow-CPU版本的. tensorflow已经支持Python3.8版本的安装.可以查看自己的Python版本信息,以及可以支持的tensorflow版本号.在Anaconda promo

  • python深度学习tensorflow入门基础教程示例

    目录 正文 1.编辑器 2.常量 3.变量 4.占位符 5.图(graph) 例子1:hello world 例子2:加法和乘法 例子3: 矩阵乘法 正文 TensorFlow用张量这种数据结构来表示所有的数据. 用一阶张量来表示向量,如:v = [1.2, 2.3, 3.5] ,如二阶张量表示矩阵,如:m = [[1, 2, 3], [4, 5, 6], [7, 8, 9]],可以看成是方括号嵌套的层数. 1.编辑器 编写tensorflow代码,实际上就是编写py文件,最好找一个好用的编辑器

  • python深度学习tensorflow实例数据下载与读取

    目录 一.mnist数据 二.CSV数据 三.cifar10数据 一.mnist数据 深度学习的入门实例,一般就是mnist手写数字分类识别,因此我们应该先下载这个数据集. tensorflow提供一个input_data.py文件,专门用于下载mnist数据,我们直接调用就可以了,代码如下: import tensorflow.examples.tutorials.mnist.input_data mnist = input_data.read_data_sets("MNIST_data/&q

  • python深度学习tensorflow安装调试教程

    目录 正文 一.安装anaconda 二.安装tensorflow 三.调试 正文 用过一段时间的caffe后,对caffe有两点感受:1.速度确实快; 2. 太不灵活了. 深度学习技术一直在发展,但是caffe的更新跟不上进度,也许是维护团队的关系:CAFFE团队成员都是业余时间在维护和更新.导致的结果就是很多新的技术在caffe里用不了,比如RNN, LSTM,batch-norm等.当然这些现在也算是旧的东西了,也许caffe已经有了,我已经很久没有关注caffe的新版本了.它的不灵活之处

  • python深度学习tensorflow卷积层示例教程

    目录 一.旧版本(1.0以下)的卷积函数:tf.nn.conv2d 二.1.0版本中的卷积函数:tf.layers.conv2d 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/pytho

  • python深度学习TensorFlow神经网络模型的保存和读取

    目录 之前的笔记里实现了softmax回归分类.简单的含有一个隐层的神经网络.卷积神经网络等等,但是这些代码在训练完成之后就直接退出了,并没有将训练得到的模型保存下来方便下次直接使用.为了让训练结果可以复用,需要将训练好的神经网络模型持久化,这就是这篇笔记里要写的东西. TensorFlow提供了一个非常简单的API,即tf.train.Saver类来保存和还原一个神经网络模型. 下面代码给出了保存TensorFlow模型的方法: import tensorflow as tf # 声明两个变量

  • Python深度学习pytorch卷积神经网络LeNet

    目录 LeNet 模型训练 在本节中,我们将介绍LeNet,它是最早发布的卷积神经网络之一.这个模型是由AT&T贝尔实验室的研究院Yann LeCun在1989年提出的(并以其命名),目的是识别手写数字.当时,LeNet取得了与支持向量机性能相媲美的成果,成为监督学习的主流方法.LeNet被广泛用于自动取款机中,帮助识别处理支票的数字. LeNet 总体来看,LeNet(LeNet-5)由两个部分组成: 卷积编码器: 由两个卷积层组成 全连接层密集快: 由三个全连接层组成 每个卷积块中的基本单元

  • Python深度学习TensorFlow神经网络基础概括

    目录 一.基础理论 1.TensorFlow 2.TensorFlow过程 1.构建图阶段 2.执行图阶段(会话) 二.TensorFlow实例(执行加法) 1.构造静态图 1-1.创建数据(张量) 1-2.创建操作(节点) 2.会话(执行) API: 普通执行 fetches(多参数执行) feed_dict(参数补充) 总代码 一.基础理论 1.TensorFlow tensor:张量(数据) flow:流动 Tensor-Flow:数据流 2.TensorFlow过程 TensorFlow

  • python深度学习tensorflow训练好的模型进行图像分类

    目录 正文 随机找一张图片 读取图片进行分类识别 最后输出 正文 谷歌在大型图像数据库ImageNet上训练好了一个Inception-v3模型,这个模型我们可以直接用来进来图像分类. 下载链接: https://pan.baidu.com/s/1XGfwYer5pIEDkpM3nM6o2A 提取码: hu66 下载完解压后,得到几个文件: 其中 classify_image_graph_def.pb 文件就是训练好的Inception-v3模型. imagenet_synset_to_huma

  • Python深度学习之实现卷积神经网络

    一.卷积神经网络 Yann LeCun 和Yoshua Bengio在1995年引入了卷积神经网络,也称为卷积网络或CNN.CNN是一种特殊的多层神经网络,用于处理具有明显网格状拓扑的数据.其网络的基础基于称为卷积的数学运算. 卷积神经网络(CNN)的类型 以下是一些不同类型的CNN: 1D CNN:1D CNN 的输入和输出数据是二维的.一维CNN大多用于时间序列. 2D CNNN:2D CNN的输入和输出数据是三维的.我们通常将其用于图像数据问题. 3D CNNN:3D CNN的输入和输出数

  • Python深度学习pytorch神经网络图像卷积运算详解

    目录 互相关运算 卷积层 特征映射 由于卷积神经网络的设计是用于探索图像数据,本节我们将以图像为例. 互相关运算 严格来说,卷积层是个错误的叫法,因为它所表达的运算其实是互相关运算(cross-correlation),而不是卷积运算.在卷积层中,输入张量和核张量通过互相关运算产生输出张量. 首先,我们暂时忽略通道(第三维)这一情况,看看如何处理二维图像数据和隐藏表示.下图中,输入是高度为3.宽度为3的二维张量(即形状为 3 × 3 3\times3 3×3).卷积核的高度和宽度都是2. 注意,

随机推荐