The size of tensor a (512) must match the size of tensor b (20) at non-singleton dimension 1

[lucasjinreal]

same input as example, but got this error:

convcrf/convcrf.py", line 598, in inference
    prediction = (self.unary_weight - self.weight) * lg_unary + \
RuntimeError: The size of tensor a (512) must match the size of tensor b (20) at non-singleton dimension 1

the input image and unary size are:

image vs unary input size: torch.Size([1, 3, 512, 1024]) vs torch.Size([1, 20, 512, 1024])