Again, this is not new in FLIF, and it isn't a strength of the format. You're describing exactly what can already be done with progressive JPEG better. Look at

Again, this is not new in FLIF, and it isn't a strength of the format. You're describing exactly what can already be done with progressive JPEG better. Look at https://uprootlabs.github.io/poly-flif/ https://uprootlabs.github.io/poly-flif/ - set truncation to 80-90% and compare to Same Size JPEG. Truncated FLIF looks like a pixelated mess, whereas JPEG at the same byte size is almost like the original (note that the site has encoded JPEG to have few progressive scans, so sometimes you get half image perfect and half blocky. This is configurable in JPEG and could be equalized to entire image being ok-ish).