Legacy ImageMagick Discussions Archive

Hi snibgo, hi fmw42 - thanks a lot!

I'd never used the "\(...\)" syntax - now I get it. Nice learning for me.

And yes, writing to JPG sucks, I shouldn't have! I'll fix it in the next version - today.

Thanks again to all.

Thanks - following your hints and a bit of googling I ended up using the -fx option like this (unix syntax):


convert "$1" -fuzz 15% -fill white -draw "color 0,0 floodfill" whited.jpg

convert whited.jpg -fx "(hue > 0.17 && hue < 0.28) && lightness < 0.9 ? black : white" \
-morphology Erode ...

I would like to extract only pixels within a certain hue bracket - let's say within 15% of pure yellow - from an image.

My purpose is to separate post-its of different colors from a picture of a whiteboard.

Ideally it's shown here:

http://imgur.com/a/nXmkq

Where this http://imgur.com/0HDxdpj ...