Fun trivia: I'm pretty confident this is the least compressible fanart I have ever come across let alone submitted. The original is 23.18 MiB with a res of 2800x4218. Normally given those dimensions, I'd halve them and recompress to WebP quality 8085, and the resulting file size for fanart at similar settings averages out to ~200 KiB (give or take - approaching 300 KiB for larger or visually complex images like this one, but lower for smaller or visually simple images). This is more respectful of server storage/bandwidth costs and the load times for anyone who gets served the same image I submit and not one that's further recompressed by their instance (the latter being what lemmy normally does, the former being what Mbin normally does). Even for complex images I usually don't struggle to hit a max size of ~300KiB, and when I do it's usually because of film grain / digital noise which can be reduced prior to compression to improve the file size vs perceived image quality tradeoff, or at most it's high-complexity detail which gets simplified down to something more manageable with a more aggressively lowered resolution.

In this case going down to 50% dimensions at my preferred quality target of 85 with WebP compression still results in a file size of ~900 KiB! Even when going down to 40% dimensions and only going for quality 80 (instead of my preferred target of 85) I'm at ~490 KiB, and still ~440 KiB at 33% dimensions at quality 80, still bigger than anything other fanart I've encountered because it has so many fine details that aren't film grain / digital noise and so can't be reduced with some light denoising. Trying to balance my preference between image quality and server resources / end user bandwidth and load times, I ended up dropping down to 33% dimensions at quality 72 to get ~300 KiB.

Can anyone tell the difference in quality while casually browsing? Well, probably not 😅 but professionals have standards damn it.

Tune in next episode for more useless uselessly specific fanart image compression trivia.