Ross <rli### [at] everestkcnet> wrote:
> i found this while reading the discussion on /. about GIF patents. I'm a
> proponant of png's, and i always hate it when the size of png's is used as
> an argument for using jpg's instead (and then see jpg's posting to p.b.i
> that are greater than 300k). Generally, GIMP seems to do a decent job of
> keeping png sizes down, but this might be usefull for some. i havn't tried
> it yet. have you?

  I have.

  What pngcrush does is to test (by default) most common zlib compression
settings or all of them (with an option) to see which one of them
compresses the given image the best.

  Compared to the maximum png compression of most programs (eg. gimp)
pngcrush compresses the file 0-5% smaller. In a few special cases it
can compress even more, like 10-20%, but this is quite rare.

  Being a lossless image format PNG can't compete with JPEG in compression
when storing photographs or other similar images. It can only compete
with line-drawing-type images, cartoony images (which don't have color
gradients) and such. Also if the image can be represented well with 256
colors then a 256-color png can often compete with a jpg (but not always).

  When I take png snapshots of things I always recompress with pngcrush
because that 1-5% is still better than nothing... :)

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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