[gforce_de]

I really needs more benchmarks, especially decompression time. Also the sizes are interesting for very small images, but for real images, there are maybe better lossy variants:

  nz_scene - PEP = 73.542 bytes,
       lossy-PNG = 43.557 bytes,
      lossy-WEBP = 26.654 bytes,
  lossy-mozcjpeg = 15.716 bytes

So it's not about filesize here, it must be decompression speed.

[msephton]

The creator says that the PEP image format is meant for small, limited colour images and of course it does lossless compression.

[gforce_de]

Thanks for making that clear. But is it worth the hassle?

https://nigeltao.github.io/blog/2021/fastest-safest-png-deco...

PNG decoding seems to be fast enough:

  tree1    - PEP =  0.412 ms PNG = 0.25 ms
  font     - PEP =  0.602 ms PNG = 0.663 ms
  nz_scene - PEP = 32.121 ms PNG = 3.069 ms

Anyway, PEP is interesting!

[fph]

It's a lossless format optimized for file size rather than decompression speed; the README seems clear enough. Made by a pixel art game dev, for compressing sprites in pixel art games, so I assume it fits a useful niche.

[msephton]

I don't see any hassle, really. It's just another image format: good for some use cases, bad for others. No one file format is perfect. It was interesting enough for me to give it a couple of hours to implement a cli and add support to my pixel app.