[whatwg] Arithmetic coded JPEGs

[Evgeny Vrublevsky]

Hello.

I'm writing about arithmetic coded JPEG support. Historically, it wasn't
supported by browsers due patents. But all of these patents are expired
several years ago, and modern libjpeg, libjpeg-turbo and mozjpeg have
optional support of the arithmetic coding.

Arithmetic coded JPEG support will allow us to recompress all existing
JPEGs losslessly, saving 10-20% of size. I've provided some examples here:
https://bugs.chromium.org/p/chromium/issues/detail?id=669501#c3

Similar ticket exists also in the Mozilla's Bugzilla:
https://bugzilla.mozilla.org/show_bug.cgi?id=680385#c17 . Now, I'm just

For now, the right place to go to move forward with this is on the

standards mailing lists, not in this bug.

Unfortunately, browsers still don't support arithmetic JPEG officially. Is
this a right place to start a discussion if it is possible to change it?

[Domenic Denicola]

Hi Evgeny, and welcome to the list!

Unfortunately, browsers still don't support arithmetic JPEG officially. Is this a right place to start a discussion if it is possible to change it?

This is a reasonable place to start such a discussion, in that browser vendors are often watching it and any of them that are interested will probably chime in with support. However, you've already filed issues on two browsers for discussion without much interest (as listed in your post), so it's not clear you'll see much more here, I'm sorry to say---browser bug trackers are often already the best wa

[Peter Kasting]

Post by Evgeny Vrublevsky
Unfortunately, browsers still don't support arithmetic JPEG officially.

Is this a right place to start a discussion if it is possible to change it?
This is a reasonable place to start such a discussion, in that browser
vendors are often watching it and any of them that are interested will
probably chime in with support. However, you've already filed issues on two
browsers for discussion without much interest (as listed in your post), so
it's not clear you'll see much more here, I'm sorry to say---browser bug
trackers are often already the best way to reach browsers.

To be fair, the Chromium bug was only filed a couple of days ago. I don't
think it would be fair to characterize us as interested or disinterested,
yet.

I posted some questions on that bug, but their answers would probably be
relevant for other vendors as well.

PK

[David Singer]

I think arithmetic coding is more problematic than you think, from a deployment and usage point of view.

Yes, it does save some bits, but alas minimum size is not what people optimize JPEG encoding for; they are much more interested in maximum compatibility. Much hardware support doesn’t include arithmetic coding, as far as I know, and even though libJPEG does, at least some users of that turn it off again. I think that’s partly because it’s quite a bit slower in libJPEG.

So, one gains maybe 10-20% compression at the expense of compatibility and performance. Not a trade-off people want to take, I fear.

sorry, practical realities bite again...

Post by Evgeny Vrublevsky
Hello.
I'm writing about arithmetic coded JPEG support. Historically, it wasn't
supported by browsers due patents. But all of these patents are expired
several years ago, and modern libjpeg, libjpeg-turbo and mozjpeg have
optional support of the arithmetic coding.
Arithmetic coded JPEG support will allow us to recompress all existing
https://bugs.chromium.org/p/chromium/issues/detail?id=669501#c3
https://bugzilla.mozilla.org/show_bug.cgi?id=680385#c17 . Now, I'm just

For now, the right place to go to move forward with this is on the

standards mailing lists, not in this bug.
Unfortunately, browsers still don't support arithmetic JPEG officially. Is
this a right place to start a discussion if it is possible to change it?
--
Best regards, Evgeny

Dave Singer

***@mac.com



David Singer
Manager, Software Standards, Apple Inc.