Thank you so much for your contribution! I came across a problem when comparing two 1channel images. The traceback threw out a 'non-singleton dimension dismatch' at line 154 'return (inp - self.shift) / self.scale'. Later I learned that this function works for 3channel images, but I am not sure if that is the reason in my case (input/target shape(B,C,H,W): (4,1,256,256)), if it is, then how can I convert to 3channel? Thanks!