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

eng.aurelienpierre.com

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

#391

Post by bobbylarrybobby »

alexey-salmin wrote: post #245
palata wrote: post #227

I find it interesting how many comments here (presumably from "tech guys") confirm what the author wrote: > So there is a real issue with the design priorities of image algos from tech guys who clearly lack historical and artistic background, and don’t talk to artists, who anyway have largely decided that they were above science, maths and other menial materialistic concerns. I am a tech guy, and when a photographer…

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.

Discretional ligatures… well, they require discretion, which the author seems to sorely lack.

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

#392

Post by suzumer »

barrkel wrote: post #40

The gradients on webp frequently look like video stills. Chroma subsampling reduces the density of available luminance approximations and the more heavily it's applied, the worse gradients look. High contrast high frequency details aren't affected much, but gradients can really suffer.

Like video, webp uses limited ycbcr, as opposed to jpeg which uses full ycbcr. This leads to grayscale jpeg looking perfect on monitors that use full rgb values, as opposed to webp which will have slight banding issues when displaying grayscale content.

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

#393

Post by abrookewood »

"See the posterized ring in the background ?"

Nope. I'm looking at this on a 2k 38" ultrawide monitor, comparing the two images at 190% zoom and I have no idea what I am looking at. I literally can't see a point of difference between them at all. I know my eyes aren't great, but is the difference really that noticeable? What am I missing?

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

#395

Post by rollcat »

doctorpangloss wrote: post #290
rollcat wrote: post #244

Earlier quoted context omitted.

> which are also black and white and have a huge gradient background That's the entire point of this article. Rather than picking a dozen different kinds of images at random, it considers the problem within the very specific context of actual photographs, made by actual professional photographers, with specific (yet not uncommon) artistic/stylistic choices. It's like showing why an audio codec sucks for cellos. Yes,…

The author just makes a ton of mistakes. Many photographers competently shoot and store RAW, and many know better than to mass convert low quality JPEGs to WebP. It’s HIS work, he can choose to make as few or as many mistakes with presenting it as possible. So I don’t think he’s representative of most photographers. It’s a technical discipline. I guess the more technically interesting POV would be to suggest a soluti…

> [...] many [photographers] know better than to mass convert low quality JPEGs to WebP.

Correct, but this is the workflow that the engineers behind WebP recommend, so I think it's entirely fair to pick on it.

> Anyway, the rant elevated my knowledge very little. It was more like anti knowledge.

Then perhaps you weren't the target audience. I'm not a photographer, and the rant has offered me a little bit more perspective.

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

#396

Post by rambambram »

smallstepforman wrote: post #208
rambambram wrote: post #147

I might be missing something because I never delved into it, but my problem with WebP is I can't save images this way from my browser. Well, I can save them, but they don't show up when I try to view them on my system (Ubuntu Mate 20.04 on RPi4).

The problem is not the format, but the software / OS you choose to use. There are OS’s that have image format libraries, and once a codec is installed, ALL apps gain the ability to use it. This was first done in the 80’s, so if your Ubuntu 20.04 doesnt support data translations, maybe its time to switch to something else.

Might be the OS indeed. Luckily I can make screenshots and save as jpg or whatever. No need to ditch Linux for me.

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

#397

Post by scns »

NekkoDroid wrote: post #343
stjohnswarts wrote: post #335

Earlier quoted context omitted.

some of those prices are insane. Why are they so much more expensive that OLED TV's of similar size? Frame rate?

I dunno about TV much since I don't use them, but I have some ideas why it might be: - Framerate - Response time - Adaptive sync - (how prone to burn-in is OLED? Monitors often have way more static images to TVs) I assume combing these all might just make it more expensive than just individually each feature

> - Framerate - Response time - Adaptive sync - (how prone to burn-in is OLED? Monitors often have way more static images to TVs)

The much more complicated electronics plus Supply & Demand. Demand for TVs should be way higher then for high end monitors.

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

#398

Post by mediumsmart »

onurtag wrote: post #152

In my opinion the worst and most distinguishable downside of webp is the forced 4:2:0 chroma subsampling. On many images with bright colors you can clearly see the color and brightness loss without an educated eye. On comparison [1] you can clearly see that the top right balloon has lost its vibrant red color. On comparison [2] the bright blue neon art on the center has lost its brightness. [1] https://storage.google…

thank you for that link - it is detectable but in my eyes neglegible for website use. What about saturation?

I have to ask, what could be the reason this gives me pale blue (other colors are okeyish) jpg > webp:

cwebp -pass 10 -m 6 -nostrong -sharp_yuv -quiet -q 60 -sharpness 2 $1 -o

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

#399

Post by mediumsmart »

ShamelessC wrote: post #378
onurtag wrote: post #152

In my opinion the worst and most distinguishable downside of webp is the forced 4:2:0 chroma subsampling. On many images with bright colors you can clearly see the color and brightness loss without an educated eye. On comparison [1] you can clearly see that the top right balloon has lost its vibrant red color. On comparison [2] the bright blue neon art on the center has lost its brightness. [1] https://storage.google…

Not to stir yet stir another debate but yeah, definitely not able to perceive the difference in either of the examples you linked. It would be helpful if that site let you drag the vertical comparison bar at least. On an iPhone 14 display.

I can see it in the second link setting webp to small in the orange reflections above the rightmost outside needle tree htms. ... oh, you cant drag it? ...

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

#400

Post by ubercow13 »

x0x0 wrote: post #367
ubercow13 wrote: post #122

Earlier quoted context omitted.

The authors point is that if you are making this tech, you should have educated eyes. And given all the confident comments in this thread claiming the author is full of shit and there's no difference, I think their frustration is justified? If you can't see the difference in the first images that's fine but you probably shouldn't be confidently claiming to know better than the author, let alone designing an image cod…

The author's point is deeply stupid. As he admits: > WebP re-encoding of an already lossy compressed JPEG So... all this shows nothing. Is webp worse than jpeg? Not addressed. He re-encoded jpeg to webp and it somehow didn't magically cure the compression artifacts he's seeing! Who coulda thunk! Any comparison starts with taking the originals, encoding to jpeg and webp, and comparing that. Or he could repeatedly enco…

Most of the comparisons are encoded from source. The one that isn't is because re-encoding is a specific recommendation from the services that they are criticising. They are specifically showing that yes, that's a bad idea.
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