卷积神经网络(CNN)服装图像分类
## 1. 设置GPU
import tensorflow as tf
gpus=tf.config.list_physical_devices("GPU")
if gpus:
gpu0 =gpus[0]
tf.config.experimental.set_memory_growth(gpu0,True)
tf.config.set_visible_devices([gpu0],"GPU")
## 2. 导入数据
import tensorflow as tf
from tensorflow.keras import datasets, layers, models
import matplotlib.pyplot as plt
(train_images, train_labels), (test_images, test_labels) = datasets.fashion_mnist.load_data()在这里插入代码片
## 3. 归一化
train_images,test_images=train_images/255.0 ,test_images/255.0
train_images.shape,test_images.shape,train_labels.shape,test_labels.shape
## 4.调整图片格式
train_images = train_images.reshape((60000, 28, 28, 1))
test_images = test_images.reshape((10000, 28, 28, 1))
train_images.shape,test_images.shape,train_labels.shape,test_labels.shape
## 5. 可视化
class_names = ['T-shirt/top', 'Trouser', 'Pullover', 'Dress', 'Coat',
'Sandal', 'Shirt', 'Sneaker', 'Bag', 'Ankle boot']
plt.figure(figsize=(20,10))
for i in range(20):
plt.subplot(5,10,i+1)
plt.xticks([])
plt.yticks([])
plt.grid(False)
plt.imshow(train_images[i], cmap=plt.cm.binary)
plt.xlabel(class_names[train_labels[i]])
plt.show()
# 二、构建CNN网络
model = models.Sequential([
layers.Conv2D(32, (3, 3), activation='relu', input_shape=(28, 28, 1)), #卷积层1,卷积核3*3
layers.MaxPooling2D((2, 2)), #池化层1,2*2采样
layers.Conv2D(64, (3, 3), activation='relu'), #卷积层2,卷积核3*3
layers.MaxPooling2D((2, 2)), #池化层2,2*2采样
layers.Conv2D(64, (3, 3), activation='relu'), #卷积层3,卷积核3*3
layers.Flatten(), #Flatten层,连接卷积层与全连接层
layers.Dense(64, activation='relu'), #全连接层,特征进一步提取
layers.Dense(10) #输出层,输出预期结果
])
model.summary() # 打印网络结构
# 三、编译
model.compile(optimizer='adam',
loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
metrics=['accuracy'])
# 四、训练模型
history = model.fit(train_images, train_labels, epochs=10,
validation_data=(test_images, test_labels))
# 五、预测
plt.imshow(test_images[1])
import numpy as np
pre = model.predict(test_images)
print(class_names[np.argmax(pre[1])])
# 六、模型评估
plt.plot(history.history['accuracy'], label='accuracy')
plt.plot(history.history['val_accuracy'], label = 'val_accuracy')
plt.xlabel('Epoch')
plt.ylabel('Accuracy')
plt.ylim([0.5, 1])
plt.legend(loc='lower right')
plt.show()
test_loss, test_acc = model.evaluate(test_images, test_labels, verbose=2)
print("测试准确率为:",test_acc)