WebP is reasonably fast, this can't be said about the other image formats. I tested WebP, FLIF and BPG when I was looking for a PNG alternative and WebP seemed to be the best choice all-around. The only downside of WebP is that it doesn't work with images larger than 16383 pixels in width or height.
2^14 pixels in both directions with 4 bytes per pixel (ARGB) puts the pixel data at a maximum size of 2^30 bytes. Just barely enough to be indexed using a 32-bit integer (even a signed one if you want)
Looks like WebP uses RIFF data chunks [1] (which look a lot like the old Amiga IFF file format), and the size of such a chunk is a 32-bit integer. Besides, 16k width/height ought to be enough for anyone ;)
I take photos of trains [1] and regularly run into file format limitations as the photos can easily reach hundreds of thousands of pixels wide.
Besides, modern cameras such as the Sony a7R II are already producing photos 8000 px wide, and the upcoming 100 megapixel cameras such as the Fujifilm will do 12000 px wide images. It's very easy to hit the limit if you're planning to shoot any panoramas.
Sorry for the ignorant question, but what does it mean for a format to be "fast"? Does it takes less time to compress the image? and why would that matter in 99% of cases?
