How to collect custom batches?

[malfonsoarquimea]

Hi!
I am currently working on a system that requires me to load batches composed of random pixels of a given set of images. More precisely, if there are N images in the dataset and batch size is B, for each epoch I need to collect N batches of size B, each one composed of B random pixels of the corresponding image. E.g. first batch is composed of B randomly selected pixels of the first image, etc.
What would be the recommended way to do this?