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6.3.5: quality of converts from gif to jpg worse than 6.2.x

Posted: 2007-09-14T10:37:07-07:00
by fkarger
Hi,

I tested the following versions of convert of ImageMagick:
ImageMagick-6.3.5-8-Q16, ImageMagick-6.3.5-0-Q16, ImageMagick-6.3.4-0-Q16,
ImageMagick-6.3.3-0-Q16, ImageMagick-6.3.2-9-Q8, ImageMagick-6.3.2-9-Q16
on Windows 2000.
I also testet ImageMagick-6.3.5-8-Q16 on Linux Fedora 6.

I tried several conversions of gifs to jpg and often oberved
the following effects:
Some colors seem to get blurred over the whole image and sometimes the resulting image seems to be the negative to the source image.
I could not observe this effect with ImageMagick-6.2.2-4-Q16.

Example: convert -geometry 30x30 source.gif dst.jpg

Interestingly convert -geometry 30x30 -colors 256 source.gif dst.jpg
often helps but not for very small geometries.

Regards,

Frank

Re: 6.3.5: quality of converts from gif to jpg worse than 6.2.x

Posted: 2007-09-14T11:44:37-07:00
by magick
Add -quality 92 to your command line (or -quality 98 or whatever).