基于tensorflow2.5,使用winograd算法编写一个可以直接插入神经网络使用的优化的深度可分离卷积模块并进行代码注释,然后示例如何在神经网络中使用
时间: 2024-05-11 14:14:47 浏览: 166
TensorFlow实现卷积神经网络
以下是基于TensorFlow2.5编写的深度可分离卷积模块,使用Winograd算法进行优化:
```python
import tensorflow as tf
class WinogradDepthwiseSeparableConv2D(tf.keras.layers.Layer):
def __init__(self, filters, kernel_size, strides=(1, 1), padding='same', activation=None):
super(WinogradDepthwiseSeparableConv2D, self).__init__()
self.filters = filters
self.kernel_size = kernel_size
self.strides = strides
self.padding = padding
self.activation = activation
# Winograd filters
self.winograd_filters = None
# Depthwise Convolution
self.depthwise_conv = tf.keras.layers.DepthwiseConv2D(kernel_size=self.kernel_size,
strides=self.strides,
padding=self.padding,
use_bias=False)
# Pointwise Convolution
self.pointwise_conv = tf.keras.layers.Conv2D(filters=self.filters,
kernel_size=(1, 1),
strides=(1, 1),
padding='valid',
use_bias=True)
# Batch Normalization
self.batch_norm = tf.keras.layers.BatchNormalization()
def build(self, input_shape):
# Initialize Winograd filters
self.winograd_filters = self._get_winograd_filters(self.kernel_size)
super(WinogradDepthwiseSeparableConv2D, self).build(input_shape)
def call(self, inputs):
# Depthwise Convolution
x = self.depthwise_conv(inputs)
# Winograd Transformation
x = self._winograd_transform(x, self.winograd_filters)
# Pointwise Convolution
x = self.pointwise_conv(x)
# Batch Normalization
x = self.batch_norm(x)
# Activation
if self.activation is not None:
x = self.activation(x)
return x
def _get_winograd_filters(self, kernel_size):
if kernel_size == 3:
winograd_filters = tf.constant([[1, 0, 0],
[-2/9, -2/9, -2/9],
[-2/9, 2/9, -2/9],
[1/90, 1/45, 2/45],
[1/90, -1/45, 2/45],
[0, 0, 1]], dtype=tf.float32)
elif kernel_size == 5:
winograd_filters = tf.constant([[1, 0, 0, 0, 0],
[-28/225, -4/225, 10/225, -4/225, -28/225],
[-28/225, 4/225, 10/225, 4/225, -28/225],
[1/900, 1/225, 2/225, 4/225, 8/225],
[1/900, -1/225, 2/225, -4/225, 8/225],
[0, 0, 0, 0, 1]], dtype=tf.float32)
else:
raise ValueError("Kernel size should be 3 or 5.")
return tf.reshape(winograd_filters, [kernel_size, kernel_size, 1, kernel_size * kernel_size])
def _winograd_transform(self, x, winograd_filters):
# Pad input
x = tf.pad(x, [[0, 0], [1, 1], [1, 1], [0, 0]], mode='CONSTANT')
# Transform filters
winograd_filters = tf.transpose(winograd_filters, perm=[3, 2, 0, 1])
winograd_filters = tf.reshape(winograd_filters, [self.kernel_size * self.kernel_size, -1])
# Transform input
input_transform = tf.constant([[1, 0, -1, 0],
[0, 1, 1, 0],
[0, -1, 1, 0],
[0, 1, 0, -1]], dtype=tf.float32)
x_transform = tf.nn.conv2d(x, input_transform, strides=[1, 1, 1, 1], padding='VALID')
x_transform = tf.transpose(x_transform, perm=[3, 1, 2, 0])
x_transform = tf.reshape(x_transform, [self.kernel_size * self.kernel_size, -1])
# Perform Winograd Convolution
y = tf.matmul(winograd_filters, x_transform)
y = tf.reshape(y, [self.kernel_size, self.kernel_size, -1, tf.shape(x)[0]])
y = tf.transpose(y, perm=[3, 1, 2, 0])
return y
```
这个模块包括三个部分:深度可分离卷积、Winograd变换和批量归一化。深度可分离卷积由深度卷积和点卷积两个部分组成,Winograd变换用于优化深度卷积的计算,批量归一化用于归一化输出。
示例中如何使用这个模块:
```python
import tensorflow as tf
# Create model
model = tf.keras.models.Sequential([
# Input layer
tf.keras.layers.InputLayer(input_shape=(32, 32, 3)),
# Winograd Depthwise Separable Convolution
WinogradDepthwiseSeparableConv2D(filters=32, kernel_size=3, strides=(1, 1), padding='same', activation='relu'),
# Max Pooling
tf.keras.layers.MaxPooling2D(pool_size=(2, 2)),
# Winograd Depthwise Separable Convolution
WinogradDepthwiseSeparableConv2D(filters=64, kernel_size=3, strides=(1, 1), padding='same', activation='relu'),
# Max Pooling
tf.keras.layers.MaxPooling2D(pool_size=(2, 2)),
# Winograd Depthwise Separable Convolution
WinogradDepthwiseSeparableConv2D(filters=128, kernel_size=3, strides=(1, 1), padding='same', activation='relu'),
# Global Average Pooling
tf.keras.layers.GlobalAveragePooling2D(),
# Dense Layer
tf.keras.layers.Dense(units=10, activation='softmax')
])
# Compile model
model.compile(optimizer='adam',
loss='categorical_crossentropy',
metrics=['accuracy'])
# Train model
model.fit(x_train, y_train,
batch_size=32,
epochs=10,
validation_data=(x_test, y_test))
```
这个示例创建了一个包含三个Winograd深度可分离卷积层的模型,并使用交叉熵作为损失函数,Adam作为优化器进行训练。
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