[HardyLeung]

My apology for not being clear. The five points are summary of what you said and I hope there is no confusion.

Right after the five points, I object to your "surgical arguments" which is along the line of "Jpeg is not too bad, and even if it is bad, there are ways to fix them". The truth is that Jpeg is actually a very poor format. Image artifact is very poor at low quality, and compression is very poor at high quality. While I don't know for sure whether WebP is really that much better at high quality (my limited experience showed that it is), I disagree with your arguments that there is "nothing wrong or unfixable about Jpeg". Our eyes are accustomed to poor web Jpeg quality but I think if something better comes along people will see it.

Also, given Opera and Chrome already support WebP, if Mozilla throws its weight behind it, I think Safari and IE will oblige in short order. The browser landscape is very different from the days of early PNG, and adoption will be quick. Just look at how quickly Microsoft transforms into the "#1" advocate of HTML5.

[jrmuizel]

My position isn't that there's "nothing wrong or unfixable about Jpeg" at all. There's lots wrong and fixable with JPEG. My problem with WebP is that it currently doesn't fix enough of the problems that JPEG has and that if we adopt it right now we might end up with another format that still has problems and will have to replace WebP with yet another format that fixes those problems later. JPEG took 6 years to standardize and has lasted for nearly 20, this suggests that we might not want to rush to commit to a 8 month old image format with a bitstream that was frozen the moment it became public.

As for support in other browsers, WebM is supported by Opera, Chrome and Firefox, plus it solves problem of being a royalty-free modern video codec and neither Safari nor IE have obliged in short order. What do you think that WebP brings that will make adoption happen faster than WebM?

[HardyLeung]

I think let's just agree that Jpeg has a lot of problems and we'd like to seek the best replacement. Obviously high-compression rate is important or else everything should migrate to PNG, but the current Jpeg tradeoff between quality and size is not just not very good. Also interestingly, there seems to be a very wide spectrum of Jpeg lib quality from decent to very bad, and I found out about that while experimenting with WebP.

WebP is different from WebM in that there are IP issues. I think WebP is more like SVG/Canvas in that vendors don't see any "hurt" in supporting them once there is enough momentum behind. Of course, your point about making sure that we don't want to support any half-baked image format. I think WebP is beyond half-baked, and an initial pledge of experimental support -- instead of an outright rejection which seems to be tone -- doesn't hurt.