High Heap memory usage

[UKTailwind]

Hi

I'm trying to use the code on a RP2040. I've got it working for small simple images but the heap usage is very high. For example a 100 by 100 image with just a single white line diagonally on a black background consumes over 30K bytes of heap not including the frame itself. Is there any way the compression can be changed to reduce this?

I tried reducing if (nkeys < 0x1000) {

but this just resulted in a corrupt gif

Thanks