WebP

With the size of the game growing with every update, I thought it might be a good time to look into space-saving options again.

Ren’Py used to have JCC as an option for images with transparent backgrounds: This would save the image and the alpha channel as lossy JPGs, reassembling them in-game.

Modern Ren’Py now has WebP support, so I thought I’d look into that a little bit…

I can’t say I know much about the pros and cons of the format, but from just some tests, it certainly looks promising.

It’s probably not the best way to do a demonstration, but the above image of May is made from saves at different levels of compression. Clearly, there’s zero difference between any of them!

No, don’t panic, I’m just kidding. Scrutinizing the images in Photoshop, I could make out some artifacts at 50% compression, but at the lowest compression settings, the differences between the two images was fairly negligible.

The size difference, on the other hand, is significant. Here’s what it looks like:
1,422 KB – Lossless PNG
942 KB – Lossless WEBP
441 KB – Lowest Compression WEBP
56 KB – 50% Compression WEBP
18 KB – Highest Compression WEBP

So, as you can see, this is a drastic improvement. Converting the character sprite directory to this format, even at the lowest compression, brings it from 222 MB down to 64.7 MB.

Unless anyone knows some reason why I shouldn’t be using this format, I’m seriously considering making the switch.