How to slice up an image into many smaller parts

[RebeccaStevens]

I have an 8K square image that I want to crop up into smaller pieces that together will assemble back into the whole. I want each split up image to be 256x256 pixels. And then I also want to have different scales of these images.

So at a 1x scale I want to generate 32x32 (1024) images.
At 0.5x scale I want to generate 16x16 (256) images.
At 0.25x scale I want to generate 8x8 (64) images.
At 0.125x scale I want to generate 4x4 (16) images.

I also need to give the images specific names so that I can then dynamically load them in (with leaflet).

What would be the best way to go about doing this?