There's probably a number of ways to do it. My naive solution would be to use segmentation masking first to simplify the problem without any background pixels. Mediapipe pose can do this. You can use pose to also segment regions, like arms and torso, to specialize the computation.

Can precompute the input image into such regions as well and mask out the person/background to just have the clothing.

That said the documentation says:

> Garment Transfer currently supports only one person in the target image. When using Garment Transfer with two or more people visible, the garment will attempt to apply to multiple targets, and place different parts of the garment on different people.

They have full pose tracking for multiple people, so this indicates this method is different and probably not relying on that previous research. It sounds more global to me which is strange as I'd expect that to be slower. Maybe their temporal pose tracking is more expensive than I'm thinking.