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Old 1st November 2008, 07:25   #56  |  Link
akupenguin
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Join Date: Sep 2004
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Quote:
Originally Posted by zeeman_88 View Post
Now regarding h264 intra compression as the best lossy still-image format. I am not aware of that and have not compared it to JPEG2000 myself. Have you run such a test? I would be interested too see these results.
My expectation for such a test is that they would give comparable quality for low to medium compression. But at high compression ratio (80 and above), I doubt h264 Intra will be able to keep up.
At high resolutions but very low bitrates, jp2k fares better than h264 since jp2k can reasonably efficiently discard whole subbands (which is almost as good as downscaling, though it still wastes a few bits), while h264 block size maxes out at 16x16. Nevertheless, in such extreme cases both jp2k and h264 benefit from downscaling the image and compressing the lower resolution version to the same filesize. And once you do that, h264 wins again. (Granted I had to tweak the resolution manually, as x264 doesn't optimize it for you.)

IOW, yes h264 fails at sufficiently low bpp, but low bpp is always avoidable.

Last edited by akupenguin; 1st November 2008 at 07:29.
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