[深度之眼]LeNetAlexNetVGGNetInceptionNetResNet实现fashion

本文使用五种经典卷积神经网络，实现fashion_mnist十分类问题，并对比准确度和运行时间 LeNet5 原理 AlexNet8 原理 VGGNet16 原理 InceptionNet10 原理 ResNet18 原理

用到的包：

import tensorflow as tf import os import numpy as np from matplotlib import pyplot as plt from tensorflow.keras.layers import Conv2D, BatchNormalization, Activation, MaxPool2D, Dropout, Flatten, Dense from tensorflow.keras import Model

加载数据集

np.set_printoptions(threshold=np.inf) fashion = tf.keras.datasets.fashion_mnist (x_train, y_train), (x_test, y_test) = fashion.load_data() x_train, x_test = x_train / 255.0, x_test / 255.0 print("x_train.shape", x_train.shape) x_train = x_train.reshape(x_train.shape[0], 28, 28, 1) # 给数据增加一个维度，使数据和网络结构匹配 x_test = x_test.reshape(x_test.shape[0], 28, 28, 1) print("x_train.shape", x_train.shape)

LeNet 网络

class LeNet5(Model): def __init__(self): super(LeNet5, self).__init__() self.c1 = Conv2D(filters=6, kernel_size=(5, 5),activation='sigmoid') self.p1 = MaxPool2D(pool_size=(2, 2), strides=2) self.c2 = Conv2D(filters=16, kernel_size=(5, 5),activation='sigmoid') self.p2 = MaxPool2D(pool_size=(2, 2), strides=2) self.flatten = Flatten() self.f1 = Dense(120, activation='sigmoid') self.f2 = Dense(84, activation='sigmoid') self.f3 = Dense(10, activation='softmax') def call(self, x): x = self.c1(x) x = self.p1(x) x = self.c2(x) x = self.p2(x) x = self.flatten(x) x = self.f1(x) x = self.f2(x) y = self.f3(x) return y

AlexNet 网络

class AlexNet8(Model): def __init__(self): super(AlexNet8, self).__init__() self.c1 = Conv2D(filters=96, kernel_size=(3, 3)) self.b1 = BatchNormalization() self.a1 = Activation('relu') self.p1 = MaxPool2D(pool_size=(3, 3), strides=2) self.c2 = Conv2D(filters=256, kernel_size=(3, 3)) self.b2 = BatchNormalization() self.a2 = Activation('relu') self.p2 = MaxPool2D(pool_size=(3, 3), strides=2) self.c3 = Conv2D(filters=384, kernel_size=(3, 3), padding='same',activation='relu') self.c4 = Conv2D(filters=384, kernel_size=(3, 3), padding='same',activation='relu') self.c5 = Conv2D(filters=256, kernel_size=(3, 3), padding='same',activation='relu') self.p3 = MaxPool2D(pool_size=(3, 3), strides=2) self.flatten = Flatten() self.f1 = Dense(2048, activation='relu') self.d1 = Dropout(0.5) self.f2 = Dense(2048, activation='relu') self.d2 = Dropout(0.5) self.f3 = Dense(10, activation='softmax') def call(self, x): x = self.c1(x) x = self.b1(x) x = self.a1(x) x = self.p1(x) x = self.c2(x) x = self.b2(x) x = self.a2(x) x = self.p2(x) x = self.c3(x) x = self.c4(x) x = self.c5(x) x = self.p3(x) x = self.flatten(x) x = self.f1(x) x = self.d1(x) x = self.f2(x) x = self.d2(x) y = self.f3(x) return y

VGGNet 网络

class VGG16(Model): def __init__(self): super(VGG16, self).__init__() self.c1 = Conv2D(filters=64, kernel_size=(3, 3), padding='same') # 卷积层1 self.b1 = BatchNormalization() # BN层1 self.a1 = Activation('relu') # 激活层1 self.c2 = Conv2D(filters=64, kernel_size=(3, 3), padding='same', ) self.b2 = BatchNormalization() # BN层1 self.a2 = Activation('relu') # 激活层1 self.p1 = MaxPool2D(pool_size=(2, 2), strides=2, padding='same') self.d1 = Dropout(0.2) # dropout层 self.c3 = Conv2D(filters=128, kernel_size=(3, 3), padding='same') self.b3 = BatchNormalization() # BN层1 self.a3 = Activation('relu') # 激活层1 self.c4 = Conv2D(filters=128, kernel_size=(3, 3), padding='same') self.b4 = BatchNormalization() # BN层1 self.a4 = Activation('relu') # 激活层1 self.p2 = MaxPool2D(pool_size=(2, 2), strides=2, padding='same') self.d2 = Dropout(0.2) # dropout层 self.c5 = Conv2D(filters=256, kernel_size=(3, 3), padding='same') self.b5 = BatchNormalization() # BN层1 self.a5 = Activation('relu') # 激活层1 self.c6 = Conv2D(filters=256, kernel_size=(3, 3), padding='same') self.b6 = BatchNormalization() # BN层1 self.a6 = Activation('relu') # 激活层1 self.c7 = Conv2D(filters=256, kernel_size=(3, 3), padding='same') self.b7 = BatchNormalization() self.a7 = Activation('relu') self.p3 = MaxPool2D(pool_size=(2, 2), strides=2, padding='same') self.d3 = Dropout(0.2) self.c8 = Conv2D(filters=512, kernel_size=(3, 3), padding='same') self.b8 = BatchNormalization() # BN层1 self.a8 = Activation('relu') # 激活层1 self.c9 = Conv2D(filters=512, kernel_size=(3, 3), padding='same') self.b9 = BatchNormalization() # BN层1 self.a9 = Activation('relu') # 激活层1 self.c10 = Conv2D(filters=512, kernel_size=(3, 3), padding='same') self.b10 = BatchNormalization() self.a10 = Activation('relu') self.p4 = MaxPool2D(pool_size=(2, 2), strides=2, padding='same') self.d4 = Dropout(0.2) self.c11 = Conv2D(filters=512, kernel_size=(3, 3), padding='same') self.b11 = BatchNormalization() # BN层1 self.a11 = Activation('relu') # 激活层1 self.c12 = Conv2D(filters=512, kernel_size=(3, 3), padding='same') self.b12 = BatchNormalization() # BN层1 self.a12 = Activation('relu') # 激活层1 self.c13 = Conv2D(filters=512, kernel_size=(3, 3), padding='same') self.b13 = BatchNormalization() self.a13 = Activation('relu') self.p5 = MaxPool2D(pool_size=(2, 2), strides=2, padding='same') self.d5 = Dropout(0.2) self.flatten = Flatten() self.f1 = Dense(512, activation='relu') self.d6 = Dropout(0.2) self.f2 = Dense(512, activation='relu') self.d7 = Dropout(0.2) self.f3 = Dense(10, activation='softmax') def call(self, x): x = self.c1(x) x = self.b1(x) x = self.a1(x) x = self.c2(x) x = self.b2(x) x = self.a2(x) x = self.p1(x) x = self.d1(x) x = self.c3(x) x = self.b3(x) x = self.a3(x) x = self.c4(x) x = self.b4(x) x = self.a4(x) x = self.p2(x) x = self.d2(x) x = self.c5(x) x = self.b5(x) x = self.a5(x) x = self.c6(x) x = self.b6(x) x = self.a6(x) x = self.c7(x) x = self.b7(x) x = self.a7(x) x = self.p3(x) x = self.d3(x) x = self.c8(x) x = self.b8(x) x = self.a8(x) x = self.c9(x) x = self.b9(x) x = self.a9(x) x = self.c10(x) x = self.b10(x) x = self.a10(x) x = self.p4(x) x = self.d4(x) x = self.c11(x) x = self.b11(x) x = self.a11(x) x = self.c12(x) x = self.b12(x) x = self.a12(x) x = self.c13(x) x = self.b13(x) x = self.a13(x) x = self.p5(x) x = self.d5(x) x = self.flatten(x) x = self.f1(x) x = self.d6(x) x = self.f2(x) x = self.d7(x) y = self.f3(x) return y

InceptionNet 网络

class ConvBNRelu(Model): def __init__(self, ch, kernelsz=3, strides=1, padding='same'): super(ConvBNRelu, self).__init__() self.model = tf.keras.models.Sequential([ Conv2D(ch, kernelsz, strides=strides, padding=padding), BatchNormalization(), Activation('relu') ]) def call(self, x): x = self.model(x, training=False) #在training=False时，BN通过整个训练集计算均值、方差去做批归一化，training=True时，通过当前batch的均值、方差去做批归一化。推理时 training=False效果好 return x class InceptionBlk(Model): def __init__(self, ch, strides=1): super(InceptionBlk, self).__init__() self.ch = ch self.strides = strides self.c1 = ConvBNRelu(ch, kernelsz=1, strides=strides) self.c2_1 = ConvBNRelu(ch, kernelsz=1, strides=strides) self.c2_2 = ConvBNRelu(ch, kernelsz=3, strides=1) self.c3_1 = ConvBNRelu(ch, kernelsz=1, strides=strides) self.c3_2 = ConvBNRelu(ch, kernelsz=5, strides=1) self.p4_1 = MaxPool2D(3, strides=1, padding='same') self.c4_2 = ConvBNRelu(ch, kernelsz=1, strides=strides) def call(self, x): x1 = self.c1(x) x2_1 = self.c2_1(x) x2_2 = self.c2_2(x2_1) x3_1 = self.c3_1(x) x3_2 = self.c3_2(x3_1) x4_1 = self.p4_1(x) x4_2 = self.c4_2(x4_1) # concat along axis=channel x = tf.concat([x1, x2_2, x3_2, x4_2], axis=3) return x class Inception10(Model): def __init__(self, num_blocks, num_classes, init_ch=16, **kwargs): super(Inception10, self).__init__(**kwargs) self.in_channels = init_ch self.out_channels = init_ch self.num_blocks = num_blocks self.init_ch = init_ch self.c1 = ConvBNRelu(init_ch) self.blocks = tf.keras.models.Sequential() for block_id in range(num_blocks): for layer_id in range(2): if layer_id == 0: block = InceptionBlk(self.out_channels, strides=2) else: block = InceptionBlk(self.out_channels, strides=1) self.blocks.add(block) # enlarger out_channels per block self.out_channels *= 2 self.p1 = GlobalAveragePooling2D() self.f1 = Dense(num_classes, activation='softmax') def call(self, x): x = self.c1(x) x = self.blocks(x) x = self.p1(x) y = self.f1(x) return y

ResNet 网络

class ResnetBlock(Model): def __init__(self, filters, strides=1, residual_path=False): super(ResnetBlock, self).__init__() self.filters = filters self.strides = strides self.residual_path = residual_path self.c1 = Conv2D(filters, (3, 3), strides=strides, padding='same', use_bias=False) self.b1 = BatchNormalization() self.a1 = Activation('relu') self.c2 = Conv2D(filters, (3, 3), strides=1, padding='same', use_bias=False) self.b2 = BatchNormalization() # residual_path为True时，对输入进行下采样，即用1x1的卷积核做卷积操作，保证x能和F(x)维度相同，顺利相加 if residual_path: self.down_c1 = Conv2D(filters, (1, 1), strides=strides, padding='same', use_bias=False) self.down_b1 = BatchNormalization() self.a2 = Activation('relu') def call(self, inputs): residual = inputs # residual等于输入值本身，即residual=x # 将输入通过卷积、BN层、激活层，计算F(x) x = self.c1(inputs) x = self.b1(x) x = self.a1(x) x = self.c2(x) y = self.b2(x) if self.residual_path: residual = self.down_c1(inputs) residual = self.down_b1(residual) out = self.a2(y + residual) # 最后输出的是两部分的和，即F(x)+x或F(x)+Wx,再过激活函数 return out class ResNet18(Model): def __init__(self, block_list, initial_filters=64): # block_list表示每个block有几个卷积层 super(ResNet18, self).__init__() self.num_blocks = len(block_list) # 共有几个block self.block_list = block_list self.out_filters = initial_filters self.c1 = Conv2D(self.out_filters, (3, 3), strides=1, padding='same', use_bias=False) self.b1 = BatchNormalization() self.a1 = Activation('relu') self.blocks = tf.keras.models.Sequential() # 构建ResNet网络结构 for block_id in range(len(block_list)): # 第几个resnet block for layer_id in range(block_list[block_id]): # 第几个卷积层 if block_id != 0 and layer_id == 0: # 对除第一个block以外的每个block的输入进行下采样 block = ResnetBlock(self.out_filters, strides=2, residual_path=True) else: block = ResnetBlock(self.out_filters, residual_path=False) self.blocks.add(block) # 将构建好的block加入resnet self.out_filters *= 2 # 下一个block的卷积核数是上一个block的2倍 self.p1 = tf.keras.layers.GlobalAveragePooling2D() self.f1 = tf.keras.layers.Dense(10, activation='softmax', kernel_regularizer=tf.keras.regularizers.l2()) def call(self, inputs): x = self.c1(inputs) x = self.b1(x) x = self.a1(x) x = self.blocks(x) x = self.p1(x) y = self.f1(x) return y

选择你想使用的模型，下面代码选择一个：

model = LeNet5() model = AlexNet8() model = VGG16() model = Inception10(num_blocks=2, num_classes=10) model = ResNet18([2, 2, 2, 2])

接下来设置训练参数：

model.compile(optimizer='adam', loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=False), metrics=['sparse_categorical_accuracy']) checkpoint_save_path = "./checkpoint/ResNet18.ckpt" if os.path.exists(checkpoint_save_path + '.index'): print('-------------load the model-----------------') model.load_weights(checkpoint_save_path) cp_callback = tf.keras.callbacks.ModelCheckpoint(filepath=checkpoint_save_path, save_weights_only=True, save_best_only=True) history = model.fit(x_train, y_train, batch_size=32, epochs=5, validation_data=(x_test, y_test), validation_freq=1, callbacks=[cp_callback]) model.summary()

保存模型参数

file = open('./weights.txt', 'w') for v in model.trainable_variables: file.write(str(v.name) + '\n') file.write(str(v.shape) + '\n') file.write(str(v.numpy()) + '\n') file.close()

可视化loss和acc

acc = history.history['sparse_categorical_accuracy'] val_acc = history.history['val_sparse_categorical_accuracy'] loss = history.history['loss'] val_loss = history.history['val_loss'] plt.subplot(1, 2, 1) plt.plot(acc, label='Training Accuracy') plt.plot(val_acc, label='Validation Accuracy') plt.title('Training and Validation Accuracy') plt.legend() plt.subplot(1, 2, 2) plt.plot(loss, label='Training Loss') plt.plot(val_loss, label='Validation Loss') plt.title('Training and Validation Loss') plt.legend() plt.show()

完成！