
Grand Image Compression Challenge at ICIP 2016 - 112233
http://jpeg.org/items/20151126_icip_challenge.html
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vanderZwan
Eh... isn't the Joint Photographic Experts Group the one that patents
everything?

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defenestration
I'm wondering, what incentive do researchers have to share their new
compression algorithms with JPEG? Especially if JPEG patents everything as you
suggest.

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joosters
If it works similarly to other standards groups, they don't take the patents
from inventors. Instead, they manage the patents and collect fees on behalf of
the (many) holders, allowing anyone to buy the rights through a single entity.
The various MPEGs and other formats like DIVX work in this way.

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0x09
No that isn't true. ISO (MPEG/JPEG) does not play a part in licensing patents
or forming patent pools, which is only natural when you consider the fact that
ISO is an international organization headquartered in Geneva and every country
has its own patent ecosystem.

Individual companies within a certain jurisdiction can certainly set up pools
and court the various rightsholders who participate in the standards process,
and that is what you see with e.g. MPEG-LA and HEVC Advance in the US. But
these have no direct connection to ISO beyond using the name and serving the
contributing organizations.

Also, JPEG and MPEG are both part of the same standards group. And Divx is
just a brand of MPEG implementations.

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vanderZwan
Ah, so I accidentally spread FUD because, well... the situation is complicated
and confusing.

Sadly I can't edit my top post any more :/

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pornel
I hope evaluation will use more diverse set of images than the subset given.
Only a couple of example images have highly saturated color, and all example
images will tolerate poorly done chroma subsampling.

On the web there are categories of images, such as logos, screenshots,
renders, large icons, photos with captions, that aren't simple enough to
compress well with lossless encoders, but become a mess when compressed with
codecs tuned for high-res photos without any sharp highly saturated edges.

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vardump
You don't need to subsample chroma in JPEG. I often disable it (use 4:4:4
sampling) if there is high color contrast detail. Say a tree with red fruit,
marketplace, kid's toys, etc.

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pornel
I know it's not necessary in JPEG, but some codecs (especially video and
therefore video-codec-derived still image formats) have only 4:2:0 option. And
if a codec chooses to use it, I'd prefer the test suite to require it done
well.

I've recently looked at it closely and found that almost every codec does
chroma subsampling incorrectly, but the error is visible mostly in computer-
generated graphics, and rarely in photos, and probably that's why nobody cared
to fix it.

[https://github.com/mozilla/mozjpeg/issues/193](https://github.com/mozilla/mozjpeg/issues/193)

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vardump
For _most_ purposes, image compression is a solved problem.

I assume this challenge exists to create a new image compression format. But I
don't see any reason why JPEG2000 doesn't happen again - a new format that
almost no one adopts. JPEG was simply good enough.

Although 12-bit color depth with JPEG comparable compression levels would sure
be nice.

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vanderZwan
Holy shit do I strongly disagree with this.

> _Although 12-bit color depth with JPEG comparable compression levels would
> sure be nice._

Exactly: there are _so many_ features - like higher bit depth, alpha
transparency, different colour spaces - missing form JPEG.

IIRC, JPG2000 wasn't adopted because back in the day we only had Internet
Explorer, which required a special plugin, it was too slow, and there weren't
many export options.

BPG and FLIF are good contenders in the lossy/lossless area though.

[http://bellard.org/bpg/](http://bellard.org/bpg/)

[http://flif.info/](http://flif.info/)

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vardump
I agree new features would be nice. Like alpha transparency like you
mentioned. Or how about cool things like depth or normal maps? I just think
almost no one cares. We represent 0.1% of the population.

The last new image format to be universally adopted was PNG in 1996. A lot of
entrants have tried ever since, but I think it'd be fair to say none of them
mattered the slightest.

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udev
This would be a good occasion to have scrutinize the compression algorithm in
BPG image format [http://bellard.org/bpg/](http://bellard.org/bpg/) .

