我正在使用 CNN 进行图像分类,但在构建不会过度拟合的网络时遇到了麻烦。我的训练集中有 4 个类别的 2000 张图像,而在我的测试集中,我有 3038 个相同的 4 个类别的图像。我的CNN如下:
def Network(input_shape, num_classes, regl2 = 0.0001, lr=0.0001):
model = Sequential()
# C1 Convolutional Layer
model.add(Conv2D(filters=32, input_shape=input_shape, kernel_size=(3,3),\
strides=(1,1), padding='valid'))
model.add(Activation('relu'))
# Pooling
model.add(MaxPooling2D(pool_size=(2,2), strides=(2,2), padding='valid'))
# Batch Normalisation before passing it to the next layer
model.add(BatchNormalization())
# C2 Convolutional Layer
model.add(Conv2D(filters=64, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Activation('relu'))
# Batch Normalisation
model.add(BatchNormalization())
# C3 Convolutional Layer
model.add(Conv2D(filters=128, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Activation('relu'))
# Batch Normalisation
model.add(BatchNormalization())
# C4 Convolutional Layer
model.add(Conv2D(filters=256, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Activation('relu'))
#Pooling
model.add(MaxPooling2D(pool_size=(2,2), strides=(2,2), padding='valid'))
# Batch Normalisation
model.add(BatchNormalization())
# C5 Convolutional Layer
model.add(Conv2D(filters=256, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Conv2D(filters=256, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Activation('relu'))
# Pooling
model.add(MaxPooling2D(pool_size=(2,2), strides=(2,2), padding='valid'))
# Batch Normalisation
model.add(BatchNormalization())
# C6 Convolutional Layer
model.add(Conv2D(filters=512, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Conv2D(filters=512, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Activation('relu'))
# Pooling
model.add(MaxPooling2D(pool_size=(2,2), strides=(2,2), padding='valid'))
# Batch Normalisation
model.add(BatchNormalization())
# C7 Convolutional Layer
model.add(Conv2D(filters=512, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Conv2D(filters=512, kernel_size=(3,3), strides=(1,1), padding='valid'))
model.add(Activation('relu'))
# Pooling
model.add(MaxPooling2D(pool_size=(2,2), strides=(2,2), padding='valid'))
# Batch Normalisation
model.add(BatchNormalization())
# Flatten
model.add(Flatten())
flatten_shape = (input_shape[0]*input_shape[1]*input_shape[2],)
# D1 Dense Layer
model.add(Dense(4096, input_shape=flatten_shape, kernel_regularizer=regularizers.l2(regl2)))
model.add(Activation('relu'))
# Dropout
model.add(Dropout(0.4))
# Batch Normalisation
model.add(BatchNormalization())
# D2 Dense Layer
model.add(Dense(4096, kernel_regularizer=regularizers.l2(regl2)))
model.add(Activation('relu'))
# Dropout
model.add(Dropout(0.4))
# Batch Normalisation
model.add(BatchNormalization())
# D3 Dense Layer
model.add(Dense(1000,kernel_regularizer=regularizers.l2(regl2)))
model.add(Activation('relu'))
# Dropout
model.add(Dropout(0.4))
# Batch Normalisation
model.add(BatchNormalization())
# Output Layer
model.add(Dense(num_classes))
model.add(Activation('softmax'))
# Compile
adam = optimizers.Adam(lr=lr)
model.compile(loss='categorical_crossentropy', optimizer=adam, metrics=['accuracy'])
return model
每次我训练和测试时,我都明显过度拟合,因为如果我测试模型,我得到的准确率很低,大约为 45%,如果我绘制它们,测试和训练的准确率曲线相距甚远。
我怎样才能以不会过拟合的方式改进我的网络?
提前致谢。