Just FYI, non-square images should work fine. Arguably that's one of the selling points of convolutional neural nets. The early big-name training sets tended to

Just FYI, non-square images should work fine. Arguably that's one of the selling points of convolutional neural nets. The early big-name training sets tended to be all square though, and if your design ends with a fully-connected layer (more common back then as well) then you're pretty locked-in for aspect ratio unless you retrain.