文章目录
- 一、前言
 - 二、前期工作
 - 1. 设置GPU(如果使用的是CPU可以忽略这步)
 - 2. 导入数据
 - 3. 查看数据
 
- 二、数据预处理
 - 1. 加载数据
 - 2. 可视化数据
 - 3. 再次检查数据
 - 4. 配置数据集
 
- 三、构建Inception V3网络模型
 - 1.自己搭建
 - 2.官方模型
 
- 五、编译
 - 六、训练模型
 - 七、模型评估
 - 二、构建一个tf.data.Dataset
 - 1.预处理函数
 
- 七、保存和加载模型
 - 八、预测
 
一、前言
我的环境:
- 语言环境:Python3.6.5
 - 编译器:jupyter notebook
 - 深度学习环境:TensorFlow2.4.1
 
往期精彩内容:
- 卷积神经网络(CNN)实现mnist手写数字识别
 - 卷积神经网络(CNN)多种图片分类的实现
 - 卷积神经网络(CNN)衣服图像分类的实现
 - 卷积神经网络(CNN)鲜花识别
 - 卷积神经网络(CNN)天气识别
 - 卷积神经网络(VGG-16)识别海贼王草帽一伙
 - 卷积神经网络(ResNet-50)鸟类识别
 - 卷积神经网络(AlexNet)鸟类识别
 - 卷积神经网络(CNN)识别验证码
 
来自专栏:机器学习与深度学习算法推荐
二、前期工作
1. 设置GPU(如果使用的是CPU可以忽略这步)
import tensorflow as tf
gpus = tf.config.list_physical_devices("GPU")
if gpus:
    tf.config.experimental.set_memory_growth(gpus[0], True)  #设置GPU显存用量按需使用
    tf.config.set_visible_devices([gpus[0]],"GPU")
 
2. 导入数据
import matplotlib.pyplot as plt
# 支持中文
plt.rcParams['font.sans-serif'] = ['SimHei']  # 用来正常显示中文标签
plt.rcParams['axes.unicode_minus'] = False  # 用来正常显示负号
import os,PIL,pathlib
# 设置随机种子尽可能使结果可以重现
import numpy as np
np.random.seed(1)
# 设置随机种子尽可能使结果可以重现
import tensorflow as tf
tf.random.set_seed(1)
from tensorflow import keras
from tensorflow.keras import layers,models
 
data_dir = "code"
data_dir = pathlib.Path(data_dir)
all_image_paths = list(data_dir.glob('*'))
all_image_paths = [str(path) for path in all_image_paths]
# 打乱数据
random.shuffle(all_image_paths)
# 获取数据标签
all_label_names = [path.split("\\")[5].split(".")[0] for path in all_image_paths]
image_count = len(all_image_paths)
print("图片总数为:",image_count)
 
data_dir = "gestures"
data_dir = pathlib.Path(data_dir)
 
3. 查看数据
image_count = len(list(data_dir.glob('*/*')))
print("图片总数为:",image_count)
 
图片总数为: 12547
 
二、数据预处理
本文主要是识别24个英文字母的手语姿势(另外两个字母的手语是动作),其中每一个手语姿势图片均有500+张。
1. 加载数据
使用image_dataset_from_directory方法将磁盘中的数据加载到tf.data.Dataset中
batch_size = 8
img_height = 224
img_width = 224
 
TensorFlow版本是2.2.0的同学可能会遇到module 'tensorflow.keras.preprocessing' has no attribute 'image_dataset_from_directory'的报错,升级一下TensorFlow就OK了。
train_ds = tf.keras.preprocessing.image_dataset_from_directory(
    data_dir,
    validation_split=0.2,
    subset="training",
    seed=123,
    image_size=(img_height, img_width),
    batch_size=batch_size)
 
Found 12547 files belonging to 24 classes.
Using 10038 files for training.
 
val_ds = tf.keras.preprocessing.image_dataset_from_directory(
    data_dir,
    validation_split=0.2,
    subset="validation",
    seed=123,
    image_size=(img_height, img_width),
    batch_size=batch_size)
 
class_names = train_ds.class_names
print(class_names)
 
['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y']
 
2. 可视化数据
plt.figure(figsize=(10, 5))  # 图形的宽为10高为5
for images, labels in train_ds.take(1):
    for i in range(8):
        
        ax = plt.subplot(2, 4, i + 1)  
        plt.imshow(images[i].numpy().astype("uint8"))
        plt.title(class_names[labels[i]])
        
        plt.axis("off")
 

plt.imshow(images[1].numpy().astype("uint8"))
 

3. 再次检查数据
for image_batch, labels_batch in train_ds:
    print(image_batch.shape)
    print(labels_batch.shape)
    break
 
(8, 224, 224, 3)
(8,)
 
Image_batch是形状的张量(8, 224, 224, 3)。这是一批形状240x240x3的8张图片(最后一维指的是彩色通道RGB)。Label_batch是形状(8,)的张量,这些标签对应8张图片
4. 配置数据集
AUTOTUNE = tf.data.AUTOTUNE
train_ds = train_ds.cache().shuffle(1000).prefetch(buffer_size=AUTOTUNE)
val_ds = val_ds.cache().prefetch(buffer_size=AUTOTUNE)
 
三、构建Inception V3网络模型
1.自己搭建
下面是本文的重点 Inception V3 网络模型的构建,可以试着按照上面的图自己构建一下 Inception V3,这部分我主要是参考官网的构建过程,将其单独拎了出来。
#=============================================================
#                  Inception V3 网络                          
#=============================================================
from tensorflow.keras.models import Model
from tensorflow.keras        import layers
from tensorflow.keras.layers import Activation,Dense,Input,BatchNormalization,Conv2D,AveragePooling2D
from tensorflow.keras.layers import GlobalAveragePooling2D,MaxPooling2D
def conv2d_bn(x,filters,num_row,num_col,padding='same',strides=(1, 1),name=None):
    
    if name is not None:
        bn_name = name + '_bn'
        conv_name = name + '_conv'
    else:
        bn_name = None
        conv_name = None
        
    x = Conv2D(filters,(num_row, num_col),strides=strides,padding=padding,use_bias=False,name=conv_name)(x)
    x = BatchNormalization(scale=False, name=bn_name)(x)
    x = Activation('relu', name=name)(x)
    return x
def InceptionV3(input_shape=[224,224,3],classes=1000):
    img_input = Input(shape=input_shape)
    x = conv2d_bn(img_input, 32, 3, 3, strides=(2, 2), padding='valid')
    x = conv2d_bn(x, 32, 3, 3, padding='valid')
    x = conv2d_bn(x, 64, 3, 3)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)
    x = conv2d_bn(x,  80, 1, 1, padding='valid')
    x = conv2d_bn(x, 192, 3, 3, padding='valid')
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)
    #================================#
    #         Block1 35x35
    #================================#
    # Block1 part1
    # 35 x 35 x 192 -> 35 x 35 x 256
    branch1x1 = conv2d_bn(x, 64, 1, 1)
    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)
    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch_pool = AveragePooling2D((3, 3), strides=(1, 1), padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 32, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],axis=3,name='mixed0')
    # Block1 part2
    # 35 x 35 x 256 -> 35 x 35 x 288
    branch1x1 = conv2d_bn(x, 64, 1, 1)
    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)
    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch_pool = AveragePooling2D((3, 3), strides=(1, 1), padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],axis=3,name='mixed1')
    # Block1 part3
    # 35 x 35 x 288 -> 35 x 35 x 288
    branch1x1 = conv2d_bn(x, 64, 1, 1)
    branch5x5 = conv2d_bn(x, 48, 1, 1)
    branch5x5 = conv2d_bn(branch5x5, 64, 5, 5)
    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch_pool = AveragePooling2D((3, 3), strides=(1, 1), padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 64, 1, 1)
    x = layers.concatenate([branch1x1, branch5x5, branch3x3dbl, branch_pool],axis=3,name='mixed2')
    #================================#
    #          Block2 17x17
    #================================#
    # Block2 part1
    # 35 x 35 x 288 -> 17 x 17 x 768
    branch3x3 = conv2d_bn(x, 384, 3, 3, strides=(2, 2), padding='valid')
    branch3x3dbl = conv2d_bn(x, 64, 1, 1)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3)
    branch3x3dbl = conv2d_bn(branch3x3dbl, 96, 3, 3, strides=(2, 2), padding='valid')
    branch_pool = MaxPooling2D((3, 3), strides=(2, 2))(x)
    x = layers.concatenate([branch3x3, branch3x3dbl, branch_pool], axis=3, name='mixed3')
    # Block2 part2
    # 17 x 17 x 768 -> 17 x 17 x 768
    branch1x1 = conv2d_bn(x, 192, 1, 1)
    branch7x7 = conv2d_bn(x, 128, 1, 1)
    branch7x7 = conv2d_bn(branch7x7, 128, 1, 7)
    branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)
    branch7x7dbl = conv2d_bn(x, 128, 1, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 1, 7)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 128, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)
    branch_pool = AveragePooling2D((3, 3), strides=(1, 1), padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
    
    x = layers.concatenate([branch1x1, branch7x7, branch7x7dbl, branch_pool],axis=3,name='mixed4')
    # Block2 part3 and part4
    # 17 x 17 x 768 -> 17 x 17 x 768 -> 17 x 17 x 768
    for i in range(2):
        branch1x1 = conv2d_bn(x, 192, 1, 1)
        branch7x7 = conv2d_bn(x, 160, 1, 1)
        branch7x7 = conv2d_bn(branch7x7, 160, 1, 7)
        branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)
        branch7x7dbl = conv2d_bn(x, 160, 1, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 7, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 1, 7)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 160, 7, 1)
        branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)
        branch_pool = AveragePooling2D(
            (3, 3), strides=(1, 1), padding='same')(x)
        branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
        x = layers.concatenate([branch1x1, branch7x7, branch7x7dbl, branch_pool],axis=3,name='mixed' + str(5 + i))
    # Block2 part5
    # 17 x 17 x 768 -> 17 x 17 x 768
    branch1x1 = conv2d_bn(x, 192, 1, 1)
    branch7x7 = conv2d_bn(x, 192, 1, 1)
    branch7x7 = conv2d_bn(branch7x7, 192, 1, 7)
    branch7x7 = conv2d_bn(branch7x7, 192, 7, 1)
    branch7x7dbl = conv2d_bn(x, 192, 1, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 7, 1)
    branch7x7dbl = conv2d_bn(branch7x7dbl, 192, 1, 7)
    branch_pool = AveragePooling2D((3, 3), strides=(1, 1), padding='same')(x)
    branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
    x = layers.concatenate([branch1x1, branch7x7, branch7x7dbl, branch_pool],axis=3,name='mixed7')
    #================================#
    #         Block3 8x8
    #================================#
    # Block3 part1
    # 17 x 17 x 768 -> 8 x 8 x 1280
    branch3x3 = conv2d_bn(x, 192, 1, 1)
    branch3x3 = conv2d_bn(branch3x3, 320, 3, 3,strides=(2, 2), padding='valid')
    branch7x7x3 = conv2d_bn(x, 192, 1, 1)
    branch7x7x3 = conv2d_bn(branch7x7x3, 192, 1, 7)
    branch7x7x3 = conv2d_bn(branch7x7x3, 192, 7, 1)
    branch7x7x3 = conv2d_bn(branch7x7x3, 192, 3, 3, strides=(2, 2), padding='valid')
    branch_pool = MaxPooling2D((3, 3), strides=(2, 2))(x)
    x = layers.concatenate([branch3x3, branch7x7x3, branch_pool], axis=3, name='mixed8')
    # Block3 part2 part3
    # 8 x 8 x 1280 -> 8 x 8 x 2048 -> 8 x 8 x 2048
    for i in range(2):
        branch1x1 = conv2d_bn(x, 320, 1, 1)
        branch3x3 = conv2d_bn(x, 384, 1, 1)
        branch3x3_1 = conv2d_bn(branch3x3, 384, 1, 3)
        branch3x3_2 = conv2d_bn(branch3x3, 384, 3, 1)
        branch3x3 = layers.concatenate(
            [branch3x3_1, branch3x3_2], axis=3, name='mixed9_' + str(i))
        branch3x3dbl = conv2d_bn(x, 448, 1, 1)
        branch3x3dbl = conv2d_bn(branch3x3dbl, 384, 3, 3)
        branch3x3dbl_1 = conv2d_bn(branch3x3dbl, 384, 1, 3)
        branch3x3dbl_2 = conv2d_bn(branch3x3dbl, 384, 3, 1)
        branch3x3dbl = layers.concatenate([branch3x3dbl_1, branch3x3dbl_2], axis=3)
        branch_pool = AveragePooling2D((3, 3), strides=(1, 1), padding='same')(x)
        branch_pool = conv2d_bn(branch_pool, 192, 1, 1)
        x = layers.concatenate([branch1x1, branch3x3, branch3x3dbl, branch_pool],axis=3,name='mixed' + str(9 + i))
    
    # 平均池化后全连接。
    x = GlobalAveragePooling2D(name='avg_pool')(x)
    x = Dense(classes, activation='softmax', name='predictions')(x)
    inputs = img_input
    model = Model(inputs, x, name='inception_v3')
    return model
model = InceptionV3()
model.summary()
 
2.官方模型
# import tensorflow as tf
# model_2 = tf.keras.applications.InceptionV3()
# model_2.summary()
 
五、编译
在准备对模型进行训练之前,还需要再对其进行一些设置。以下内容是在模型的编译步骤中添加的:
- 损失函数(loss):用于衡量模型在训练期间的准确率。
 - 优化器(optimizer):决定模型如何根据其看到的数据和自身的损失函数进行更新。
 - 指标(metrics):用于监控训练和测试步骤。以下示例使用了准确率,即被正确分类的图像的比率。
 
# 设置优化器,我这里改变了学习率。
opt = tf.keras.optimizers.Adam(learning_rate=1e-5)
model.compile(optimizer=opt,
              loss='sparse_categorical_crossentropy',
              metrics=['accuracy'])
 
六、训练模型
epochs = 10
history = model.fit(
    train_ds,
    validation_data=val_ds,
    epochs=epochs
)
 
Epoch 1/10
1255/1255 [==============================] - 146s 77ms/step - loss: 3.9494 - accuracy: 0.3102 - val_loss: 0.6095 - val_accuracy: 0.8481
Epoch 2/10
1255/1255 [==============================] - 70s 56ms/step - loss: 0.7071 - accuracy: 0.8370 - val_loss: 0.1968 - val_accuracy: 0.9430
Epoch 3/10
1255/1255 [==============================] - 70s 56ms/step - loss: 0.2956 - accuracy: 0.9380 - val_loss: 0.0834 - val_accuracy: 0.9757
Epoch 4/10
1255/1255 [==============================] - 70s 56ms/step - loss: 0.1344 - accuracy: 0.9766 - val_loss: 0.0452 - val_accuracy: 0.9884
Epoch 5/10
1255/1255 [==============================] - 71s 57ms/step - loss: 0.0566 - accuracy: 0.9954 - val_loss: 0.0265 - val_accuracy: 0.9916
Epoch 6/10
1255/1255 [==============================] - 72s 57ms/step - loss: 0.0282 - accuracy: 0.9988 - val_loss: 0.0158 - val_accuracy: 0.9956
Epoch 7/10
1255/1255 [==============================] - 72s 57ms/step - loss: 0.0150 - accuracy: 0.9994 - val_loss: 0.0218 - val_accuracy: 0.9924
Epoch 8/10
1255/1255 [==============================] - 72s 57ms/step - loss: 0.0188 - accuracy: 0.9979 - val_loss: 0.0125 - val_accuracy: 0.9968
Epoch 9/10
1255/1255 [==============================] - 71s 57ms/step - loss: 0.0122 - accuracy: 0.9986 - val_loss: 0.0542 - val_accuracy: 0.9833
Epoch 10/10
1255/1255 [==============================] - 70s 56ms/step - loss: 0.0178 - accuracy: 0.9964 - val_loss: 0.0213 - val_accuracy: 0.9924
 
七、模型评估
acc = history.history['accuracy']
val_acc = history.history['val_accuracy']
loss = history.history['loss']
val_loss = history.history['val_loss']
epochs_range = range(epochs)
plt.figure(figsize=(12, 4))
plt.subplot(1, 2, 1)
plt.suptitle("微信公众号(K同学啊)中回复(DL+13)可获取数据")
plt.plot(epochs_range, acc, label='Training Accuracy')
plt.plot(epochs_range, val_acc, label='Validation Accuracy')
plt.legend(loc='lower right')
plt.title('Training and Validation Accuracy')
plt.subplot(1, 2, 2)
plt.plot(epochs_range, loss, label='Training Loss')
plt.plot(epochs_range, val_loss, label='Validation Loss')
plt.legend(loc='upper right')
plt.title('Training and Validation Loss')
plt.show()
 
二、构建一个tf.data.Dataset
1.预处理函数
acc = history.history['accuracy']
val_acc = history.history['val_accuracy']
loss = history.history['loss']
val_loss = history.history['val_loss']
epochs_range = range(epochs)
plt.figure(figsize=(12, 4))
plt.subplot(1, 2, 1)
plt.plot(epochs_range, acc, label='Training Accuracy')
plt.plot(epochs_range, val_acc, label='Validation Accuracy')
plt.legend(loc='lower right')
plt.title('Training and Validation Accuracy')
plt.subplot(1, 2, 2)
plt.plot(epochs_range, loss, label='Training Loss')
plt.plot(epochs_range, val_loss, label='Validation Loss')
plt.legend(loc='upper right')
plt.title('Training and Validation Loss')
plt.show()
 
七、保存和加载模型
# 保存模型
model.save('model/12_model.h5')
 
# 加载模型
new_model = tf.keras.models.load_model('model/12_model.h5')
 
八、预测
# 采用加载的模型(new_model)来看预测结果
plt.figure(figsize=(10, 5))  # 图形的宽为10高为5
for images, labels in val_ds.take(1):
    for i in range(8):
        ax = plt.subplot(2, 4, i + 1)  
        
        # 显示图片
        plt.imshow(images[i].numpy().astype("uint8"))
        
        # 需要给图片增加一个维度
        img_array = tf.expand_dims(images[i], 0) 
        
        # 使用模型预测图片中的人物
        predictions = new_model.predict(img_array)
        plt.title(class_names[np.argmax(predictions)])
        plt.axis("off")
 




















