Arguments: in_channels: int, number of channels in the input tensor. Default is 3 for RGB images. depth: int, number of MaxPools in the U-Net. start_filts: int, number of convolutional filters for the first conv.
(self, num_classes, in_channels=3, depth=5,
start_filts=64, up_mode='transpose',
merge_mode='concat', **kwargs)