def MEAN_Spot(opt): # channel 1 inputs1 = layers.Input(shape=(42,42,1)) conv1 = layers.Conv2D(3, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.001))(inputs1) bn1 = layers.BatchNormalization()(conv1) pool1 = layers.MaxPooling2D(pool_size=(3, 3), padding='same', strides=(3,3))(bn1) do1 = layers.Dropout(0.3)(pool1) # channel 2 inputs2 = layers.Input(shape=(42,42,1)) conv2 = layers.Conv2D(3, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.001))(inputs2) bn2 = layers.BatchNormalization()(conv2) pool2 = layers.MaxPooling2D(pool_size=(3, 3), padding='same', strides=(3,3))(bn2) do2 = layers.Dropout(0.3)(pool2) # channel 3 inputs3 = layers.Input(shape=(42,42,1)) conv3 = layers.Conv2D(8, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.001))(inputs3) bn3 = layers.BatchNormalization()(conv3) pool3 = layers.MaxPooling2D(pool_size=(3, 3), padding='same', strides=(3,3))(bn3) do3 = layers.Dropout(0.3)(pool3) # merge 1 merged = layers.Concatenate()([do1, do2, do3]) # interpretation 1 merged_conv = layers.Conv2D(8, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.1))(merged) merged_pool = layers.MaxPooling2D(pool_size=(2, 2), padding='same', strides=(2,2))(merged_conv) flat = layers.Flatten()(merged_pool) flat_do = layers.Dropout(0.2)(flat) # outputs outputs = layers.Dense(1, activation='linear', name='spot')(flat_do) #Takes input u, v, os model = keras.models.Model(inputs=[inputs1, inputs2, inputs3], outputs=[outputs]) model.compile( loss={'spot':'mse'}, optimizer=opt, metrics={'spot':tf.keras.metrics.MeanAbsoluteError()}, ) return model 如何添加通道注意力、空间注意力

要添加通道注意力和空间注意力，可以按照以下步骤进行：

1. 导入相应的库：

from tensorflow.keras import layers
from tensorflow.keras import backend as K

2. 定义通道注意力函数：

def channel_attention(inputs, reduction_ratio=8):
    # 获取输入张量的尺寸
    input_shape = K.int_shape(inputs)
    # 获取通道数
    channels = input_shape[-1]
    # 计算压缩后的通道数
    units = channels // reduction_ratio
    # 定义共享的全连接层
    shared_layer_one = layers.Dense(units, activation='relu', kernel_initializer='he_normal', use_bias=True, bias_initializer='zeros')
    shared_layer_two = layers.Dense(channels, kernel_initializer='he_normal', use_bias=True, bias_initializer='zeros')
    # 计算均值
    avg_pool = layers.GlobalAveragePooling2D()(inputs)
    # 通过全连接层获得激活的均值
    avg_pool = shared_layer_one(avg_pool)
    # 通过全连接层获得激活的权重
    avg_pool = shared_layer_two(avg_pool)
    # 将均值和权重相乘，并将结果送入 sigmoid 函数
    channel_attention = layers.multiply([inputs, layers.Activation('sigmoid')(avg_pool)])
    return channel_attention

3. 定义空间注意力函数：

def spatial_attention(inputs):
    # 计算均值和最大值
    avg_pool = layers.Lambda(lambda x: K.mean(x, axis=3, keepdims=True))(inputs)
    max_pool = layers.Lambda(lambda x: K.max(x, axis=3, keepdims=True))(inputs)
    # 将均值和最大值拼接在一起
    concat = layers.Concatenate(axis=3)([avg_pool, max_pool])
    # 通过卷积层获取激活的权重
    spatial_attention = layers.Conv2D(filters=1, kernel_size=7, activation='sigmoid', padding='same', kernel_initializer='he_normal', use_bias=False)(concat)
    # 将权重和输入张量相乘
    return layers.multiply([inputs, spatial_attention])

4. 在模型中添加注意力：

# channel 1
inputs1 = layers.Input(shape=(42,42,1))
conv1 = layers.Conv2D(3, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.001))(inputs1)
ca1 = channel_attention(conv1)
sa1 = spatial_attention(ca1)
bn1 = layers.BatchNormalization()(sa1)
pool1 = layers.MaxPooling2D(pool_size=(3, 3), padding='same', strides=(3,3))(bn1)
do1 = layers.Dropout(0.3)(pool1)

# channel 2
inputs2 = layers.Input(shape=(42,42,1))
conv2 = layers.Conv2D(3, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.001))(inputs2)
ca2 = channel_attention(conv2)
sa2 = spatial_attention(ca2)
bn2 = layers.BatchNormalization()(sa2)
pool2 = layers.MaxPooling2D(pool_size=(3, 3), padding='same', strides=(3,3))(bn2)
do2 = layers.Dropout(0.3)(pool2)

# channel 3
inputs3 = layers.Input(shape=(42,42,1))
conv3 = layers.Conv2D(8, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.001))(inputs3)
ca3 = channel_attention(conv3)
sa3 = spatial_attention(ca3)
bn3 = layers.BatchNormalization()(sa3)
pool3 = layers.MaxPooling2D(pool_size=(3, 3), padding='same', strides=(3,3))(bn3)
do3 = layers.Dropout(0.3)(pool3)

# merge 1
merged = layers.Concatenate()([do1, do2, do3])

# interpretation 1
merged_conv = layers.Conv2D(8, (5,5), padding='same', activation='relu', kernel_regularizer=l2(0.1))(merged)
merged_pool = layers.MaxPooling2D(pool_size=(2, 2), padding='same', strides=(2,2))(merged_conv)
flat = layers.Flatten()(merged_pool)
flat_do = layers.Dropout(0.2)(flat)

# outputs
outputs = layers.Dense(1, activation='linear', name='spot')(flat_do)

#Takes input u, v, os
model = keras.models.Model(inputs=[inputs1, inputs2, inputs3], outputs=[outputs])
model.compile(
    loss={'spot':'mse'},
    optimizer=opt,
    metrics={'spot':tf.keras.metrics.MeanAbsoluteError()},
)
return model

在上面的代码中，我们将 channel_attention() 和 spatial_attention() 函数分别应用于每个通道，然后将它们的输出与原始输入进行相乘，以获得加强的特征表示。