grid of masks

Hi

I don't really know hot to explain this in search engine language so forgive me if its been addressed before. I'd like to break an image into many discreet pieces that I can resize and blend independently.

For starters Id like to try this on a grid. I'm looking for something like 20x40. That would be 800 masks. If i draw them by hand it would take me forever and I don't even know if AE can handle a project with that many layers.

Does anybody have any tips for doing this kind of thing?

Thanks