BPG Image format • Hacker News Board

Re: BPG Image format

#241

Post by frontsideair » Sat, Dec 06, 2014, 2:46 AM UTC

ANTSANTS wrote: post #237

frontsideair wrote: post #232

Earlier quoted context omitted.

> I'm disagreeing with you because I dislike you > I dislike you because... Are you even aware you made my exact point?

I disagree! You have the cause and effect mixed up. It's normal to dislike certain groups of people you strongly disagree with. For example, I imagine we both dislike gay bashers pretty strongly. You, on the other hand, were suggesting that CamperBob2 was arguing with you purely because he didn't like you, which would be pretty silly if it were true.

I suggested the sole reason of him defending the status quo was that it was challenged by people he didn't like. I still believe it's true.

Re: BPG Image format

#242

Post by xanderjanz » Sat, Dec 06, 2014, 2:48 AM UTC

sillysaurus3 wrote: post #161

pslam wrote: post #148

The big story here is this introduces a new image file format without requiring you to upgrade a browser or download a plugin . Those aren't PNGs of representative images you're looking at - that's BPG decoding happening in your browser. So we don't like HVEC due to patent worries? Fine, we can swap in another format and use the same technique. We don't have an I-frame format for Daala that's finalized yet? Fine, we…

Problem is that you can't link to BPG images yet. Specifically, right click -> copy link location. If only the rightclick menu could be customized by JS. Adding only a limited number of entries to the menu seems like it'd be okay.

You wouldn't really have to change the right click menu. You could put an invisible html div over top the images, and give them the correct link, instead of the raw decompressed image data. So a user would think they are right clicking the image, when really they are right clicking our overlay.

Re: BPG Image format

#243

Post by pornel » Sat, Dec 06, 2014, 3:02 AM UTC

ChuckMcM wrote: post #91

Is there anything this guy can't do? Seriously. I have been wishing there was a JPEG equivalent with an alpha channel for like forever. That allows better compositing to arbitrary background images or patterns. Now the question is how long before browsers might support it natively.

> I have been wishing there was a JPEG equivalent with an alpha channel for like forever.

JPEG 2000 works in Safari. JPEG XR in IE. A gracefully-degrading JPEG XT is in the works: http://www.jpeg.org/jpegxt/index.html

Lossy PNG with alpha works in all browsers: http://pngquant.org (not equivalent in compression ratios, but still 4 times better than normal PNG).

Re: BPG Image format

#244

Post by pornel » Sat, Dec 06, 2014, 3:03 AM UTC

1ris wrote: post #16

Why not use Daala to start from? The overlapping transform probably help especially for still images, and the patent situation is probably at least better.

There's online Daala encoder: http://people.xiph.org/~xiphmont/demo/daala/update1.shtml

Re: BPG Image format

#245

Post by pornel » Sat, Dec 06, 2014, 3:18 AM UTC

TD-Linux wrote: post #138

msoad wrote: post #108

How does it compare to WebP? Also, how you measures lossy image quality? What are the metrics? I hope it's not just by looking at result and judging.

Looking at the result and judging is actually the best and most important metric. There are numerical metrics, like SSIM, but they are always worse than human comparison trials. You're optimizing for what looks best to a human in the end, after all.

It's very hard to create a fair test.

The problem with human judgement that it's very imprecise. You're unlikely to notice difference between JPEG at Q=90 and Q=95, but you can't say it doesn't matter, because that can cause 40% difference in file size. OTOH objective metrics can easily spot that.

"Looks the same to me" leaves a lot of room for error and you could be unfairly telling one format to save much more detail than the other. And almost by definition these are the details you're least likely to be able to see.

There's also a pitfall of choosing image that looks subjectively "nicer" rather than closer to the original. Codecs that are better (e.g. faithfully preserve noise) may be judged as worse than another codec that's an accidental Instagram filter.

Re: BPG Image format

#246

Post by geofft » Sat, Dec 06, 2014, 3:27 AM UTC

malandrew wrote: post #229

geofft wrote: post #225

Earlier quoted context omitted.

I agree that you can't generalize the opinions of two people (or even three). But you certainly can't generalize from zero.

You're assuming that ANTSANTS is generalizing from zero. Since he's linked to one example of one individual that is mature enough to realize that the importance of that common bitmap isn't its origin but what concepts and ideas in the field of image compression those set of pixels have been used to demonstrate, and how those ideas relate to machine learning. Pointers Gone Wild is a great blog, with great technical co…

> You're assuming that ANTSANTS is generalizing from zero.

No, I'm not. I'm asking: "I'm curious if you're basing this belief on actual information from the people in question, or just your intuition about what they probably think." If he's got statistically stronger evidence than my anecdotes (which are more than two, but yes, still anecdotes), I'd love to hear it! If not, I'm curious what other evidence or argument he has for the claim he made.

Re: BPG Image format

#247

Post by panzi » Sat, Dec 06, 2014, 3:27 AM UTC

mronge wrote: post #224

TD-Linux wrote: post #203

Earlier quoted context omitted.

Some devices do have hardware JPEG decoding, however all mobile browsers do software JPEG decoding, often with the SIMD-accelerated libjpeg-turbo. This is the software video decoder, by the way: https://github.com/brion/ogv.js

How come all mobile browser uses software JPEG decoding? Is it because of the startup latency of the hardware decoder?

Maybe it has something to do with the browsers displaying the images progressively as they are loaded. Maybe the hardware decoders don't support that? That's guessed.

Re: BPG Image format

#248

Post by mark-r » Sat, Dec 06, 2014, 3:49 AM UTC

pervycreeper wrote: post #236

mark-r wrote: post #18

I was ready to pass by this post with a yawn until I saw where it was coming from: Fabrice Bellard. He's no doubt an absolute freakin' genius. And if anybody knows about image conversion, it's him. Even the things he does just for fun are impressive. Have you ever booted up Linux inside your browser? http://bellard.org/jslinux/

>I was ready to pass by this post with a yawn until I saw where it was coming from Would this have been less interesting or valuable if it hadn't been made by a hacker celebrity?

New file format proposals generally aren't news, unless they're already implemented in some popular product. Finding out the latest amazing thing that Fabrice Bellard has been working on, that's news. And that it's already implemented in your browser via Javascript? Priceless.

Re: BPG Image format

#249

Post by ChrisGranger » Sat, Dec 06, 2014, 4:04 AM UTC

asah wrote: post #233

holy crap, check this out: http://img1.buyersbestfriend.com/mkg/snackspage/images/bpg.h... 186,967 ==> 29,872 and indistinguishable, 6.25:1 (and pls tell me if it breaks on your browser - I want to push this live!!!) adam

That's far from indistinguishable to me. It's actually quite obvious that the BPG is blurring detail at that compression ratio.

Edit: it's particularly noticeable in the wood grain patterns. Also, there's a soft grey dot to the left of the top of the lamp, 100px or so, that's entirely missing in the BPG. There are loads more examples...

Edit again: the color saturation of the rug is pretty washed-out as well.

Re: BPG Image format

#250

Post by akshatpradhan » Sat, Dec 06, 2014, 4:04 AM UTC

pslam wrote: post #148

The big story here is this introduces a new image file format without requiring you to upgrade a browser or download a plugin . Those aren't PNGs of representative images you're looking at - that's BPG decoding happening in your browser. So we don't like HVEC due to patent worries? Fine, we can swap in another format and use the same technique. We don't have an I-frame format for Daala that's finalized yet? Fine, we…

If you want Designers to start using this, then we need a photoshop plugin, an illustrator plugin, a Sketch plugin, a pixelmator plugin. Make it easier for us to export images as a .BGP. If the images are truly smaller without affecting the current user experience of users using mostly modern web browsers, then we're more likely to pick up on using this.