似乎tf.nn.convolution
应该能够进行4D卷积,但是我无法成功创建Keras图层以使用此功能。
我曾尝试使用Keras Lambda
层包装tf.nn.convolution
函数,但也许其他人有更好的主意?
我想利用数据的高维结构,因此重塑可能无法捕获数据集的性质。
超级酷的问题。
这需要一个自定义层(具有可训练的参数)。以下接受任意数量的尺寸,您可以通过kernel_size
进行控制。
class Conv(Layer):
def __init__(self, filters, kernel_size, padding='VALID', **kwargs):
self.filters = filters
self.kernel_size = kernel_size #must be a tuple!!!!
self.padding=padding
super(Conv, self).__init__(**kwargs)
#using channels last!!!
def build(self, input_shape):
spatialDims = len(self.kernel_size)
allDims = len(input_shape)
assert allDims == spatialDims + 2 #spatial dimensions + batch size + channels
kernelShape = self.kernel_size + (input_shape[-1], self.filters)
#(spatial1, spatial2,...., spatialN, input_channels, output_channels)
biasShape = tuple(1 for _ in range(allDims-1)) + (self.filters,)
self.kernel = self.add_weight(name='kernel',
shape=kernelShape
initializer='uniform',
trainable=True)
self.bias = self.add_weight(name='bias',
shape = biasShape,
initializer='zeros',
trainable=True)
self.built = True
def call(self, inputs):
results = tf.nn.convolution(inputs, self.kernel, padding=self.padding)
return results + self.bias
def compute_output_shape(self, input_shape)
sizes = input_shape[1:-1]
if self.padding='VALID' or self.padding='valid':
sizes = [s - kSize + 1 for s, kSize in zip(sizes, self.kernel_size)]
return input_shape[:1] + sizes + (self.filters,)