MaxPooling3D classkeras.layers.MaxPooling3D(
pool_size=(2, 2, 2),
strides=None,
padding="valid",
data_format=None,
name=None,
**kwargs
)
最大池化操作,用于3D数据(空间或时空).
沿其空间维度(深度、高度和宽度)对输入进行下采样,通过在输入窗口(大小由pool_size定义)中取每个输入通道的最大值.窗口沿每个维度按strides移动.
参数:
pool_size: 整数或3个整数的元组,用于下采样的因子(dim1, dim2, dim3).如果只指定一个整数,则所有维度将使用相同的窗口长度.
strides: 整数或3个整数的元组,或None.步幅值.如果为None,则默认为pool_size.如果只指定一个整数,则所有维度将使用相同的步幅大小.
padding: 字符串,"valid"或"same"(不区分大小写)."valid"表示无填充."same"结果是在输入的左右或上下均匀填充,使得输出具有与输入相同的高度/宽度维度.
data_format: 字符串,"channels_last"或"channels_first".输入中维度的顺序."channels_last"对应于形状为(batch, spatial_dim1, spatial_dim2, spatial_dim3, channels)的输入,而"channels_first"对应于形状为(batch, channels, spatial_dim1, spatial_dim2, spatial_dim3)的输入.它默认为在~/.keras/keras.json中的image_data_format值.如果你从未设置它,则它将是"channels_last".
输入形状:
data_format="channels_last":
形状为(batch_size, spatial_dim1, spatial_dim2, spatial_dim3, channels)的5D张量data_format="channels_first":
形状为(batch_size, channels, spatial_dim1, spatial_dim2, spatial_dim3)的5D张量输出形状:
data_format="channels_last":
形状为(batch_size, pooled_dim1, pooled_dim2, pooled_dim3, channels)的5D张量data_format="channels_first":
形状为(batch_size, channels, pooled_dim1, pooled_dim2, pooled_dim3)的5D张量示例:
depth = 30
height = 30
width = 30
channels = 3
inputs = keras.layers.Input(shape=(depth, height, width, channels))
layer = keras.layers.MaxPooling3D(pool_size=3)
outputs = layer(inputs) # 形状: (batch_size, 10, 10, 10, 3)