Mikolaj Machowski on wrote...
| Joel Poloney scripsit:
| >
| > Any suggestions?
|
| Don't use ImageMagick for PNG optimization? IM is great tool but this is
| not strength. To minimize PNG sizes use opt-png.
|
One point... There are two types pf PNG compressors.
One compresses the image to the best PNG internal represention
without loss of quality.
The other does color quantization and dithering to a limited 256 color
color table (posibly preserving some semi-transparency).
IM does not try to find the 'best' or 'smallest' lossless format, but
concentrates of getting it right. The only real way to find the
smallest for any 'random' image, is actually to try and compress the
image into every internal PNG format and then pick the best! that takes
a lot of time.
Also the PNG8 output format will get IM to do the color quantization and
dither for the smaller limited color table (pallette) format. However
it does do by using the same methods using for GIF, whcih means it does
not preverve semi-transparency. That is it is only as good as GIF,
though may, or may not be any smaller. (Prehaps someone can compare the
two formats.
Hmmm... quick test (different image may have different results).
convert rose: rose.gif
convert rose: PNG8:rose.png
4157 rose.gif
3936 rose.png
Looks like PNG pallette format compresses better!!!
It would be nice if IM can output a PNG8 image with semi-transparency,
but that is up to the IM developer who handles the PNG encoder.
Anthony Thyssen ( System Programmer ) <[EMAIL PROTECTED]>
-----------------------------------------------------------------------------
Brisbane (Australia) had been Terra's Capital city for hundreds of
years now, and its (space) port with long open approaches over the
continental center and open Pacific, was the planets busiest.
--- Dean Alan Foster, ``Orphan Star''
-----------------------------------------------------------------------------
Anthony's Home is his Castle http://www.cit.gu.edu.au/~anthony/
_______________________________________________
Magick-users mailing list
[email protected]
http://studio.imagemagick.org/mailman/listinfo/magick-users
