keras实现resnet对fashion-mnist数据集分类,并绘制图像
时间: 2023-07-21 10:29:04 浏览: 152
好的,我可以为您提供代码实现。在这里,我将使用Keras中的ResNet50预训练模型,并使用Fashion-MNIST数据集对十种服装进行分类。首先,我们需要安装一些必要的库:
```
!pip install tensorflow
!pip install keras
!pip install matplotlib
```
接下来,我们将加载数据集并进行预处理:
```python
import numpy as np
import keras
from keras.datasets import fashion_mnist
from keras.preprocessing.image import ImageDataGenerator
# 数据集路径
(x_train, y_train), (x_test, y_test) = fashion_mnist.load_data()
# 将图像转换为RGB格式
x_train = np.repeat(x_train[..., np.newaxis], 3, -1)
x_test = np.repeat(x_test[..., np.newaxis], 3, -1)
# 批量大小
batch_size = 32
# 数据增强
train_datagen = ImageDataGenerator(
rescale=1./255,
shear_range=0.2,
zoom_range=0.2,
horizontal_flip=True)
# 没有数据增强的验证数据生成器
val_datagen = ImageDataGenerator(rescale=1./255)
# 训练集生成器
train_generator = train_datagen.flow(
x_train,
keras.utils.to_categorical(y_train),
batch_size=batch_size)
# 验证集生成器
val_generator = val_datagen.flow(
x_test,
keras.utils.to_categorical(y_test),
batch_size=batch_size)
```
接下来,我们将加载ResNet50模型,并对其进行微调,以适应我们的数据集:
```python
from keras.applications.resnet50 import ResNet50
from keras.layers import Dense, GlobalAveragePooling2D
from keras.models import Model
# 加载ResNet50模型,不包括顶层(全连接层)
base_model = ResNet50(weights='imagenet', include_top=False)
# 添加全局平均池化层
x = base_model.output
x = GlobalAveragePooling2D()(x)
# 添加全连接层,输出为十个类别
predictions = Dense(10, activation='softmax')(x)
# 构建我们需要训练的完整模型
model = Model(inputs=base_model.input, outputs=predictions)
# 冻结ResNet50的所有层,以便在训练过程中不更新它们的权重
for layer in base_model.layers:
layer.trainable = False
```
现在,我们可以开始训练模型了:
```python
from keras.optimizers import SGD
# 编译模型,指定损失函数、优化器和评价指标
model.compile(loss='categorical_crossentropy',
optimizer=SGD(lr=0.001),
metrics=['accuracy'])
# 训练模型
history = model.fit_generator(
train_generator,
steps_per_epoch=x_train.shape[0] // batch_size,
epochs=10,
validation_data=val_generator,
validation_steps=x_test.shape[0] // batch_size)
```
最后,我们可以使用matplotlib库绘制训练和验证的准确率和损失曲线:
```python
import matplotlib.pyplot as plt
# 绘制训练和验证的准确率曲线
plt.plot(history.history['accuracy'])
plt.plot(history.history['val_accuracy'])
plt.title('Model accuracy')
plt.ylabel('Accuracy')
plt.xlabel('Epoch')
plt.legend(['Train', 'Val'], loc='upper left')
plt.show()
# 绘制训练和验证的损失曲线
plt.plot(history.history['loss'])
plt.plot(history.history['val_loss'])
plt.title('Model loss')
plt.ylabel('Loss')
plt.xlabel('Epoch')
plt.legend(['Train', 'Val'], loc='upper left')
plt.show()
```
现在您应该可以使用这些代码实现您的需求了。
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