That's just progressive decoding, though, and is only possible if you encoded the image correctly (which is optional). You can also do similar things with progr

That's just progressive decoding, though, and is only possible if you encoded the image correctly (which is optional). You can also do similar things with progressive jpeg, png, and webp, with jpeg being the most flexible. The unique part AFAIK is that you can order the data blocks however you want, allowing progressive loading that prioritizes more important or higher detailed areas: https://opensource.googleblog.com/2021/09/using-saliency-in-progressive-jpeg-xl-images.html https://opensource.googleblog.com/2021/09/using-saliency-in-... (your thumbnails may or may not look terrible this way, as well. really better suited for progressive loading)