snip3r77:

I understood that (4,4) or (2,2) is reducing by a factor of 4 or 2 ?
Is it uncommon to use non square kernels?


Yes, the spatial reduction would be 4x and 2x for these kernel shapes and strides.
It might be uncommon to use non-square kernels, but this doesn’t mean that you shouldn’t use them in your model, if you think they make sense for whatever reason.



 snip3r77:

So do we usually hand calculate these outputs or do we leave it for Pytorch to do so? Or do we need to understand some of these things under hood but let Pytorch to do the heavy lifting.


You could calculate it manually, but for complicated use cases with an uncommon stride, dilation etc., I just print the output shape and adapt the parameters to match my desired output.