请帮我使用2.2.0的TensorFlow来搭建一个ResNet-50的网络框架
时间: 2024-03-08 17:47:17 浏览: 125
好的,以下是使用TensorFlow 2.2.0搭建ResNet-50的网络框架的代码示例:
```python
import tensorflow as tf
from tensorflow.keras.layers import Input, Conv2D, MaxPooling2D, BatchNormalization, ReLU, Add, GlobalAveragePooling2D, Dense
from tensorflow.keras.models import Model
def identity_block(X, filters, stage, block):
"""
实现恒等块
参数:
X - 输入的tensor类型的数据,维度为(批量大小, 图像高度, 图像宽度, 图像通道数)
filters - 整数,指定主路径中间的卷积层的过滤器数目
stage - 整数,用于命名层,取决于其在网络中的位置
block - 用于命名层,取决于其在网络中的位置
返回:
X - 恒等块的输出,tensor类型,维度为(批量大小, 图像高度, 图像宽度, 图像通道数)
"""
# 定义命名规则
conv_name_base = 'res' + str(stage) + block + '_branch'
bn_name_base = 'bn' + str(stage) + block + '_branch'
# 获取过滤器
F1, F2 = filters
# 保存输入数据,用于后续添加
X_shortcut = X
# 主路径的第一部分
X = Conv2D(filters=F1, kernel_size=(1, 1), strides=(1, 1), padding='valid', name=conv_name_base+'2a', kernel_initializer=tf.keras.initializers.glorot_uniform(seed=0))(X)
X = BatchNormalization(axis=3, name=bn_name_base+'2a')(X)
X = ReLU()(X)
# 主路径的第二部分
X = Conv2D(filters=F2, kernel_size=(3, 3), strides=(1, 1), padding='same', name=conv_name_base+'2b', kernel_initializer=tf.keras.initializers.glorot_uniform(seed=0))(X)
X = BatchNormalization(axis=3, name=bn_name_base+'2b')(X)
X = ReLU()(X)
# 主路径的第三部分,添加恒等块
X = Add()([X, X_shortcut])
X = ReLU()(X)
return X
def convolutional_block(X, filters, stage, block, strides=(2, 2)):
"""
实现卷积块
参数:
X - 输入的tensor类型的数据,维度为(批量大小, 图像高度, 图像宽度, 图像通道数)
filters - 整数,指定主路径中间的卷积层的过滤器数目
stage - 整数,用于命名层,取决于其在网络中的位置
block - 用于命名层,取决于其在网络中的位置
strides - 步幅
返回:
X - 卷积块的输出,tensor类型,维度为(批量大小, 图像高度, 图像宽度, 图像通道数)
"""
# 定义命名规则
conv_name_base = 'res' + str(stage) + block + '_branch'
bn_name_base = 'bn' + str(stage) + block + '_branch'
# 获取过滤器
F1, F2 = filters
# 保存输入数据,用于后续添加
X_shortcut = X
# 主路径的第一部分
X = Conv2D(filters=F1, kernel_size=(1, 1), strides=strides, padding='valid', name=conv_name_base+'2a', kernel_initializer=tf.keras.initializers.glorot_uniform(seed=0))(X)
X = BatchNormalization(axis=3, name=bn_name_base+'2a')(X)
X = ReLU()(X)
# 主路径的第二部分
X = Conv2D(filters=F2, kernel_size=(3, 3), strides=(1, 1), padding='same', name=conv_name_base+'2b', kernel_initializer=tf.keras.initializers.glorot_uniform(seed=0))(X)
X = BatchNormalization(axis=3, name=bn_name_base+'2b')(X)
X = ReLU()(X)
# 附加路径
X_shortcut = Conv2D(filters=F2, kernel_size=(1, 1), strides=strides, padding='valid', name=conv_name_base+'1', kernel_initializer=tf.keras.initializers.glorot_uniform(seed=0))(X_shortcut)
X_shortcut = BatchNormalization(axis=3, name=bn_name_base+'1')(X_shortcut)
# 主路径的第三部分,添加卷积块
X = Add()([X, X_shortcut])
X = ReLU()(X)
return X
def ResNet50(input_shape=(224, 224, 3), classes=1000):
"""
实现ResNet50
参数:
input_shape - 输入图像的维度
classes - 分类数目
返回:
model - Keras框架的模型
"""
# 定义模型输入
X_input = Input(input_shape)
# 0填充
X = tf.keras.layers.ZeroPadding2D((3, 3))(X_input)
# Stage 1
X = Conv2D(filters=64, kernel_size=(7, 7), strides=(2, 2), name='conv1', kernel_initializer=tf.keras.initializers.glorot_uniform(seed=0))(X)
X = BatchNormalization(axis=3, name='bn_conv1')(X)
X = ReLU()(X)
X = MaxPooling2D(pool_size=(3, 3), strides=(2, 2))(X)
# Stage 2
X = convolutional_block(X, filters=[64, 256], stage=2, block='a', strides=(1, 1))
X = identity_block(X, filters=[64, 256], stage=2, block='b')
X = identity_block(X, filters=[64, 256], stage=2, block='c')
# Stage 3
X = convolutional_block(X, filters=[128, 512], stage=3, block='a', strides=(2, 2))
X = identity_block(X, filters=[128, 512], stage=3, block='b')
X = identity_block(X, filters=[128, 512], stage=3, block='c')
X = identity_block(X, filters=[128, 512], stage=3, block='d')
# Stage 4
X = convolutional_block(X, filters=[256, 1024], stage=4, block='a', strides=(2, 2))
X = identity_block(X, filters=[256, 1024], stage=4, block='b')
X = identity_block(X, filters=[256, 1024], stage=4, block='c')
X = identity_block(X, filters=[256, 1024], stage=4, block='d')
X = identity_block(X, filters=[256, 1024], stage=4, block='e')
X = identity_block(X, filters=[256, 1024], stage=4, block='f')
# Stage 5
X = convolutional_block(X, filters=[512, 2048], stage=5, block='a', strides=(2, 2))
X = identity_block(X, filters=[512, 2048], stage=5, block='b')
X = identity_block(X, filters=[512, 2048], stage=5, block='c')
# 平均池化层
X = GlobalAveragePooling2D()(X)
# 全连接层
X = Dense(units=classes, activation='softmax', name='fc'+str(classes), kernel_initializer=tf.keras.initializers.glorot_uniform(seed=0))(X)
# 创建模型
model = Model(inputs=X_input, outputs=X, name='ResNet50')
return model
```
您可以按照以下方式使用该模型:
```python
model = ResNet50(input_shape=(224, 224, 3), classes=1000)
model.summary()
```
这将打印出模型结构和参数数量的概述。
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