normalization.py 文件源码

def call(self, x, mask=None):
        def image_expand(tensor):
            return K.expand_dims(K.expand_dims(tensor, -1), -1)

        def batch_image_expand(tensor):
            return image_expand(K.expand_dims(tensor, 0))

        hw = K.cast(x.shape[2] * x.shape[3], K.floatx())
        mu = K.sum(x, [-1, -2]) / hw
        mu_vec = image_expand(mu) 
        sig2 = K.sum(K.square(x - mu_vec), [-1, -2]) / hw
        y = (x - mu_vec) / (K.sqrt(image_expand(sig2)) + K.epsilon())

        scale = batch_image_expand(self.scale)
        shift = batch_image_expand(self.shift)
        return scale*y + shift 
#       else:
#           raise NotImplemented("Please complete `CycGAN/layers/padding.py` to run on backend {}.".format(K.backend()))