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Re:Better Portable Graphics by dahart on Friday July 12, 2019 @11:52AM (#20421590)
The JPEG was compressed to death deliberately, yes. That's the point of the comparison; for the same (tiny) data size BPG gives you a clearly better result. BPG is workable in situations where JPEG isn't.

> For goodness sake, just reduce the resolution if nothing else.

Reducing the resolution would not work and is not the same thing. You would still get 8x8 DC blocks in a smaller JPEG at the same compression rate, and higher detail in the BPG. The BPG is provably better than the JPEG, and since you already know that and talked about it above, I'm a little confused by your argument.

Re:Better Portable Graphics by ZeroGravitas on Friday July 12, 2019 @01:21PM (#20422412)
I think there often is a point when reducing the bitrate further while keeping the same resolution is a worse choice than dropping the resolution. I believe one of the tricks of AV1 is to internalise this trade-off.

More generally, doing visual comparisons of codecs is full of traps. Since quality often falls off rapidly at a certain point it's possible to show your codec off by choosing the exact point to compare to maximise the difference. This is almost certainly the case if you're comparing against jpeg and it's starting to totally fall apart.

It's not that it doesn't correctly show that one is worse than the other but it's probably not a good visual reflection of the true scale of the difference any more than ramping up the bitrate until everyone would think they are indistinguishable.

Re:Better Portable Graphics by dahart on Friday July 12, 2019 @04:35PM (#20424254)
Sure, yes, but the comparison in question isn't the only comparison, it's just one of many. Letting people see the difference visually for themselves is more tangible and less questionable that putting up two file size numbers and claiming they're equal quality. And if you think about it, it similarly wouldn't completely be fair to BPG to turn up the quality so that the JPEG looked reasonably good, because the BPG file would be in the range of diminishing returns per byte.

It is fair to point out that JPEG falls apart below a certain compression threshold while BPG doesn't, even if it's a little bit apples to oranges. I prefer the way @enriquito said it https://news.ycombinator.com/item?id=20419900 but I disagree with the hyperbolic claims in this thread that this comparison is outrageous or complete spin or cheating. It's a data point that has some actual merit, and BTW happens to agree with the other data points we have.