PyTorch (and other ML frameworks that I know about) actually implement cross-correlation in the functions named convolution.
The difference is just the reversal of the filter.
filt = torch.from_numpy(np.ascontiguousarray(testFilt[::-1, ::-1])).type(torch.float32)
filt = filt.unsqueeze(0).unsqueeze(0)
Now it produces the same results.
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