"saturation" with -fx don't work?

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"saturation" with -fx don't work?

Post by bio » 2006-09-19T04:09:31-07:00

Hi everyone :)

I'm tring extracting from a jpeg image like this (in.jpg)


only the pixels that have a NOT GRAY color.

My idea is producing a black&white mask like this (mask.png)


and go to this final result (out.png)


So... I know that gray pixels have R=G=B or saturation=0.

The first step I tried was:

convert in.jpg -fx "saturation>0" mask.png

BUT I receive an error:

convert: unable to parse expression 'saturation'

Is this a bug or the "saturation" expression don't exist anymore?

I'm running imagemagick 6.2.9 Q8 on Windows XP.
Thanks everyone can help me.

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Post by anthony » 2006-09-19T19:25:56-07:00

saturation was the very last addition to the -fx operator. You have to be at the very latest BETA version for it to work.
Anthony Thyssen -- Webmaster for ImageMagick Example Pages


Post by bio » 2006-09-20T01:14:21-07:00

Thank you anthony!

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