Legacy ImageMagick Discussions Archive

I work in Windows XP and use IM-6.8.0-Q16. And I want to reduce number of the image http://www.keeshond.com.ua/wp-content/u ... %D1%82.gif unique colors (to 4 colors). For this I use a next command: "convert input_file.gif +dither -colors 4 output_file.gif". After executing of this command the output file contains a dog with a white nose.
But when I installed IM-6.3.9-Q16 the output file has been good, without replacing opaque colors by transparency background.
What the difference between the versions and why they return different results?
Thanks!

This works fine for me on Mac OSX Snow Leopard IM 6.8.0.4 Q16

convert 1dog.gif -alpha off +dither -colors 4 -alpha on 1dog_tmp1.gif


Many things have changed since your old 6.3.9 version of IM. That version is over 400 versions old.

fmw42, thanks a lot for reply. It works fine. But I think that this solution is not a good practice (off the transparency, reduce colors, on the transparency. I am afraid the performance losing). In my opinion IM must to solve problems with tranparently images. Or am I wrong?

I note that for png it can not work (see http://assets.tumblr.com/images/logo.png?alpha&6). May be it's depends on png multi-alpha-color?