Thanks for your efforts and yay, that works here too! I can paste them even. Nice. Interestingly, I copied a JPG by right clicking in Firefox and it wound up as a PNG when I pasted that. But maybe that's the browser? Still, it'd be neat if the site converts to something more efficient like WebP and maybe caps the res at 4k ...though maybe storage is cheap enough at this point that we could each put a full res SotD from our phones for the next decade without really being a burden? ...and now I wonder if the transcoding can be done client side via wasm or something. Yawn, I should sleep, rambling.
Oh! One thing though: earlier I tried pasting my SotD to another Lemmy instance to see if that works and it did fine. I didn't post it and cancelled the preview. However the image stuck around. Wondered if and how those get mopped up, maybe a cron job? It seems to be there still some hours later, might check tomorrow just out of curiosity.
(heh I think you restarted while I was trying to post this so will also be interesting if the image persists, though presumably shouldn't be orphaned now that it's referenced in a comment?)
Just poked around because I was curious, it does look like the config for pict-rs lets you specify a format to convert things to and a max size/quality: https://git.asonix.dog/asonix/pict-rs/src/branch/main/pict-rs.toml#L237
I'd suggest WebP with a quality of 85 and max dimensions of 3840x3840 (because 4k is 3840x2160).
That takes djundjila's photo for today (a 4236x2677 jpeg) from 1.9Mb down to 360Kb for a 3840x2427 WebP.
You might also consider AVIF as that's widely supported as well and looking like it'll probably become the new standard but for now is a bit CPU intensive until CPUs start adding SIMD for it. Too bad JPEGXL lost momentum, it was kinda better (and less CPU intensive). But if the server doesn't mind chewing on it ...that same SotD as a quality 66 AVIF is just 160Kb, eg. less than a tenth the size.
For more info about quality settings: https://www.industrialempathy.com/posts/avif-webp-quality-settings/