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Strange PNG behavior
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| cypherswipe 2005-12-07, 6:55 pm |
| If you use PNG compression on a complex, photographic image, level 3
achieves the best compression. At level 4, filesize makes a huge jump,
then fades down steadily until level 9, at which point the image is
still larger than it is at level 1 compression.
What changes from level 3 compression to level 4 compression?
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| Willem 2005-12-07, 6:55 pm |
| cypherswipe wrote:
) If you use PNG compression on a complex, photographic image, level 3
) achieves the best compression. At level 4, filesize makes a huge jump,
) then fades down steadily until level 9, at which point the image is
) still larger than it is at level 1 compression.
) What changes from level 3 compression to level 4 compression?
As a stab-in-the-dark guess: below level 4, the (sliding ?) window is so
small that it picks up on the local statistics, which tend to vary wildly.
But that's just a guess.
SaSW, Willem
--
Disclaimer: I am in no way responsible for any of the statements
made in the above text. For all I know I might be
drugged or something..
No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT
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