Hi Chen Yun:
Now I have rewritten SuperPixelPooling operator and it seems work (I got reasonable training loss and testing accuracy),
but I’m not sure whether it is really perfect.
I’m a caffe user before, where I have to write both the forward() and backward() for a new layer.
Here I only implement the forward() for the SuperPixelPooling operator, all the operations in forward() are based on
torch.autograd.Variable.
So do I need to write backward()  for the new operator?