[tubs]

Interesting you default to paeth.

Only working on grayscale 16bit images with only the lower 10bits populated I never found it reduced image size. But I was doing per scan adaptive filtering so maybe if I was only allowed one filter for the entire image that would be it?

Just wondering if you did any experiments with different filter strategies?

[mattdesl]

I think in the inputs I tested, I found Paeth to be the best for lower file sizes. I haven’t tested it extensively and to be honest, I should probably include some easier API for per-scanline filter selection rather than just a global choice. It should be possible right now with the lower level functions the library exposes, but not as easy.