Legacy ImageMagick Discussions Archive

Hello,

I'd like to reduce red tint in areas where red color isn't visually dominant. I've got and idea to play with something like:

abs(b-g) > 0.1 && r-max(b,g) < 0.1 ? r*0.9

Two questions:

- how to implement it with -fx ; for now it responds
convert.exe: unable to parse expression `r' @ error/fx.c/FxEvaluateSubexpression/2307.

- any other idea how to solve that problem?

$ convert -version
Version: ImageMagick 6.9.3-5 Q8 x64 2016-02-20 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2015 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Visual C++: 180040629
Features: Cipher DPC Modules OpenMP
Delegates (built-in): bzlib cairo freetype jng jp2 jpeg lcms lqr openexr pangocairo png ps rsvg tiff webp xml zlib

The "?" operator is ternary: it needs three expressions. You are missing a colon and the third expression, eg: When the first expression is true, the result is r*0.9. When it is false, the result is r. (Of course, put whatever you need for the third expression.)

Thank you very much. I've improved my command. Pure RGB path was nonsense, solution which works perfectly for me: