JPEG XR write support - half the file size of JPEG

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Xip
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JPEG XR write support - half the file size of JPEG

Post by Xip » Tue Dec 28, 2010 10:44 am

See: http://en.wikipedia.org/wiki/JPEG_XR

"delivers a lossy compressed image of better perceptive quality than JPEG at less than half the file size". As well as having other advantages as described in the link. So this sounds like the best format for archiving pictures! XnView currently has read support but not write support. Microsoft's website:
http://www.microsoft.com/windows/window ... s/wmphoto/

Irving
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Re: JPEG XR write support - half the file size of JPEG

Post by Irving » Thu Jan 13, 2011 4:15 am

Xip wrote:
"delivers a lossy compressed image of better perceptive quality than JPEG at less than half the file size". As well as having other advantages as described in the link. So this sounds like the best format for archiving pictures!
It's lossy! That means data is lost forever, meaning it's not worth a flip for archiving.

I prefer .png's.

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Drahken
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Re: JPEG XR write support - half the file size of JPEG

Post by Drahken » Thu Jan 13, 2011 9:02 am

Xnview DOES support saving in HD photo format, which is an earlier form of the jpeg-xr format.

However, it doesn't really matter. As with all such claims on all new image formats, the improvement between hdphoto & standard jpeg is greatly exaggerated. HDphoto only nets a small improvement in filesize for similar quality, you could achieve very much the same results by using jpegs with arithmetic coding.
Similar claims of insane quality/size improvements in jpeg2000 were made, yet in practice jpeg2000 actually has roughly equal or lower quality than standard jpeg. Part of the problem with all these claims is that they base "quality" on lack of noise, and neglect to properly factor in lack of detail.


irving- It has both lossy AND lossLESS modes. The lossless mode would be fine for archiving photos (although the lossless mode doesn't save any space at all. It's slightly better than PNG on photographic images, but not as good as lossless jpeg2000.)
Irving is of course correct though in stating that lossy formats are not good formats for archiving purposes.


I ran some tests, and for a given photo;
{lossless}
HDPHOTO= 823KB
PNG= 947KB
JPEG2000= 750KB

{lossy}
JPEG (Q91)= 207KB
HDPHOTO (Q90)= 167KB
JPEG2000 (Q85)= 185KB

In the lossy group, all images were roughly the same subjective quality. You can see that hdphoto does give a noticable size improvement, but nowhere near the "half the file size" that is claimed.

I would have included jpeg-ls (lossless jpeg) in my tests, but unfortunately xnview doesn't support saving in that format (opening, but not saving).
Oh the feuhrer, oh the feuhrer, oh the feuhrer's nipples bonk!

Irving
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Re: JPEG XR write support - half the file size of JPEG

Post by Irving » Fri Jan 14, 2011 5:33 am

Drahken wrote:

irving- It has both lossy AND lossLESS modes.
Yes, you're right. It's just that when the first thing you read is "delivers a lossy compressed image of better perceptive quality" then you'll usually faint before clicking on a link. :wink:

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Re: JPEG XR write support - half the file size of JPEG

Post by xnview » Thu Mar 03, 2011 9:52 am

Pierre.

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