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WebP is so great except it's not (2021)

eng.aurelienpierre.com

291–300 of 411 posts

Re: WebP is so great except it's not (2021)

#291

Earlier quoted context omitted.

OLED is overwhelmingly reserved to high-end TVs and phones as well, so I think that point is moot.

My base iPhone 12 mini from years ago has OLED, so do a lot of cheaper Android phones. Gaming displays are far less common than these.

Phones have a smaller display which makes them easier to manufacter.

Re: WebP is so great except it's not (2021)

#292
post #168

Earlier quoted context omitted.

VP8 was never competitive so most of the energy went into VP9, which did beat H264.

It beat H.264 in terms of quality/size but not in terms of hardware support. This is why Google Meet is the laggiest video conference software, they keep trying to make VP9 a thing while the others stuck with H.264. And now there's H.265.

Google marketed it that way but I could never reproduce a meaningful size savings without noticeable quality loss. You need to serve a LOT of video before even the top-end 10% savings was worth it, especially if your traffic was spread across many items so doubling your storage cost cancelled out a fair chunk of the total. I have no doubt that YouTube saw a savings but I don’t know how many other sites did, and I would be curious what the savings was relative to the extra power used by the millions of client devices which could’ve streamed H.264 at 10% CPU versus having the fan on high.

Re: WebP is so great except it's not (2021)

#293
post #170
post #145

Earlier quoted context omitted.

I have an extremely hard time perceiving any difference on a 27" 4K monitor. I am not even sure I really see them. The examples are just bad. If you want to show something, screenshot and enlarge it to show the artifacts.

> The examples are just bad. If you want to show something, screenshot and enlarge it to show the artifacts. Yes! Where's the red underlines and diffs? I can see the background banding, but the foreground looks the same at a glance except that some of them look ambiguously "off" in ways that could just be placebo. You'd think a visual artist would be more interested in visual communication and not just a wall of text…

I downloaded the images and then compared them via Beyond Compare.

After that it was pretty obvious what the author is talking about.

Re: WebP is so great except it's not (2021)

#294
post #220

Earlier quoted context omitted.

I will respond to you since you posted about this so called "SINGLE IMAGE" three times in this post already. Ackchually, the blog post contains a comparison over TWO IMAGEs. But since you work with codecs, surely you understand that the blog post is complaining about how WebP interacts with gradients in general and not just about the specific images in the blog post. JXL was getting plenty of attention before the Chr…

To make a conclusion about how a codec handles image features you need to to quantitative comparison across a big enough data set to make conclusions about any kind of generalized quality. This goes triple for modern codecs like JPEG XL, VP8/9, AV1/AVIF, etc. because they deliberately make tradeoffs when compressing based on how the image will SEEM to people, not how pixel correct it is. Note just how many people say…

The author explains why thinking in terms of averages "across a big enough data set" isn't enough.

>Call me crazy, but I don’t give a shit about averages. For a gaussian "normal" process, probabilities say half of your sample will be above and half will be below the average (which is also the median in a gaussian distribution). If we designed cars for the average load they would have to sustain, it means we would kill about half of the customers. Instead, we design cars for the worst foreseeable scenario, add a safety factor on top, and they still kill a fair amount of them, but a lot fewer than in the past. [...]

>As a photographer, I care about robustness of the visual output. Which means, as a designer, designing for the worst possible image and taking numerical metrics with a grain of salt. And that whole WebP hype is unjustified, in this regard. It surely performs well in well chosen examples, no doubt. The question is : what happens when it doesn’t ? I can’t fine-tune the WebP quality for each individual image on my website, that’s time consuming and WordPress doesn’t even allow that. I can’t have a portfolio of pictures with even 25 % posterized backgrounds either, the whole point of a portfolio is to showcase your skills and results, not to take a wild guess on the compression performance of your image backend. Average won’t do, it’s simply not good enough.

Re: WebP is so great except it's not (2021)

#295

Earlier quoted context omitted.

While I agree with the rational component of the article (webp may be inappropriate for artistic photos) I had to force myself to read it. The "t" in the font screws me up completely, I tried twice to wipe the screen of my phone then thought that maybe it's a background picture getting in the way. So overall I find author's aesthetic sense very questionable which contrasts with his high-moral-ground tone.

For me it's the horrible layout. For God's sake, stop making narrow columns of text. Having the text take up most of my monitor is much more pleasant to read.

Long lines of text cause significantly more eye strain than reasonably short ones. Generally, one should try to have ~80 characters per line of text.

Re: WebP is so great except it's not (2021)

#296
post #7

Earlier quoted context omitted.

I must admit, I'm not sure why JPEG XL is viewed so favourably on HN, it's not something I know a ton about, but my understanding is that the big advantage of AVIF is that you can reuse hardware decoders built into devices for AV1 for the images. It being a strict improvement over JPEG is nice for the developers not having to go back to the source image for an upgrade, but that seems like a pretty small benefit that…

Then doesn't that follow the line of argument for why AV1 isn't being adopted, either? Namely, lack of hardware support? I can understand why jxl isn't a dominant web format, but I don't see where avif has any place being a web format currently.

AV1 is being adopted? Almost every modern bit of hardware has AV1 decoding baked into it now, which is a huge hurdle to pass.

Re: WebP is so great except it's not (2021)

#298

Earlier quoted context omitted.

While I agree with the rational component of the article (webp may be inappropriate for artistic photos) I had to force myself to read it. The "t" in the font screws me up completely, I tried twice to wipe the screen of my phone then thought that maybe it's a background picture getting in the way. So overall I find author's aesthetic sense very questionable which contrasts with his high-moral-ground tone.

The "t" or the "ct" ligature?

Wow I am reading it at 170% zoom, and in the fourth paragraph the word "distribution" which contains the "st" ligature is automatically cut and "hyphenated" between the "s" and the "t" letters. But the ligature remains : half the ligature at the end of one line, and the other half of that ligature at the beginning of the next line ! This looks wrong. CSS has probably missed an edge case here. Or is it the job of some "text renderer" in the browser ?

Re: WebP is so great except it's not (2021)

#299
post #7

Earlier quoted context omitted.

I must admit, I'm not sure why JPEG XL is viewed so favourably on HN, it's not something I know a ton about, but my understanding is that the big advantage of AVIF is that you can reuse hardware decoders built into devices for AV1 for the images. It being a strict improvement over JPEG is nice for the developers not having to go back to the source image for an upgrade, but that seems like a pretty small benefit that…

AVIF kinda needs hardware decoding, because otherwise it’s considerably more expensive than the traditional codecs. Even with hardware decoding, I’m not sure if AVIF is actually faster/chaper—compared in https://jpegxl.io/articles/faq/#%E2%8F%A9speedfeatures , “AVIF” takes 7× as long as libjpeg-turbo to decode, and I don’t believe hardware en coders tend to bring that big a performance difference over software, but I…

You kind of ignore the case where almost every device is going to do AV1 hardware decoding (which very much appears to be the trend), if that is significantly faster/cheaper battery wise then AV1 still has a big advantage. Comparing single-core software decoding speed seems like a benchmark designed to make JXL look good, not something that actually matters.

> AVIF reduces the amount of traffic required, but will tend to consume more power. This is the general compression tradeoff.

Again, you seem to be ignoring hardware decoding. Dedicated silicon can be many magnitudes more efficient than doing something in software. To take an extreme example with a ton of effort into the efficiency: look at mining bitcoin on a CPU vs an ASIC. I'm not saying the difference will be that big, but it may well be worthwhile.

As to buggy/too much effort/cost of hardware, that's precisely why it makes sense to piggy-back on AV1, a format that already has a lot of incentive to implement in hardware, and the work already done to make it work well. You need that kind of compression for video, and people are putting in the effort to make it work well, so AVIF gets that effectively for free.

Re: WebP is so great except it's not (2021)

#300
post #219
post #166

Earlier quoted context omitted.

This cuts against WebP more: all of Google’s marketing was “it’s a third smaller!!!!” and then when you looked they were comparing it to unoptimized libjpeg outout and using computational metrics like SSIM which only crudely approximate what humans notice about image quality. I did the same comparison the author did when WebP came out but used an optimized JPEG encoder and found the same conclusion: when you produced…

In what way does "anything cut" against anything when you do cherry picked single datum point comparison? There isn't a codec pair in this world where you can't make a cherry picked comparison where one of them is worse (I've done plenty of those).

Criticism of cherry-picking cuts against WebP because the marketing campaign for that codec relied on cherry-picking both the least optimized JPEG codec and the most favorable metrics for comparison. If you had humans comparing images or enabled JPEG optimization you saw far less exciting numbers for WebP - usually under 10% savings, not uncommonly negative – and there were other formats which consistently outperformed it. You can see the mood around that time here:

https://calendar.perfplanet.com/2014/mozjpeg-3-0/

Even a decade later, however, Google repeats the 25-34% claim and their performance tools tell developers they should use a modern format, which by sheer coincidence means the one they invented rather than the best ones on the market.

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