>>308982
I understand exactly what that means, and referring to GIF's ability (correctly termed "offsets", and shared, as I said, with WebP lossless animated, in addition to additional interframe compression) to update one single subsidiary opaque rectangle as "delta compression" is almost but not quite entirely absurd. The term refers to any technique that reuses data across frames to reduce bitrate or rendering overhead.
>video codecs
As I said, WebP lossless is unrelated to video codecs, sharing far more design heritage with PNG.
>overcome the limitations of a very old format
>It was inferior to APNG on release
PNG was already 14 years old, progress in entropy encoders inevitably made squeezing more diminishing gains from DEFLATE a losing game. I don't know what to say other than that your contrarian sour grapes anecdotes don't align with mine nor any large study.
>the actual revolutionary upgrade (JPEG XL) is mature and ready to completely supercede GIF, PNG, and JPEG all in a single format.
I hope so. Remember JPEG 2000, and before that FIF, was set to do the same thing.
>>308992
Indeed, one of AV2's promised features is greatly improved lossless coding.
>>308993
>web developers can implement simple CSS that serves up a fallback image without requiring the use of Javascript
Very true, this is why tons of sites serve HEIF in spite of Safari being the only browser that supports it out of the box.
>you are imposing a requirement for browsers to keep maintaining support for reading it into their codebase
Browsers shouldn't incorporate any embed decoding in their codebase to begin with. That's why still image codecs on the web advanced at the pace of molasses while video codecs (and PDF!) progressed rapidly. Them knuckling under to JPEG XL isn't enough, we need the web to frictionlessly permit the continuous adoption of more advanced still image codecs.
Browser vendors have nursed a delusion, dating back to the Netscape days, they will completely subsume all functions of OSs. In recent times, following the elimination of plugins and then tightening of add-ons/extensions, as well as WHATWG's inmates running the W3C asylum, this has further crystalized into their statically linked ball of mud being a flawless diamond of features that users should neither need nor want to change from its defaults as shipped. That hubris and everything flowing from it must be thoroughly buckbroken.
Speaking of which, 99.999% of images that compress well with lossless codecs shouldn't be stored as bitmaps at all, but as vectorized SVGs, which is doubly true since such assets (including anime) are almost invariably created as vectors. Probably the only legitimate use cases for lossless raster codecs are raw assets (why would you ever use a web browser for that?) and, indeed, retro vidya pixel art autism.