derMatze wrote:I need to colorize an image with an hex-code. So I have the original image and an hexcode+alpha like 15243C + 90. That should add #15 to the R-Channel, #24 to the G channel and so on.
I tried this with -channel and -fx but it doesn't work at all, not with #15 or 15 or the decimal 21...
-channel R -fx 'r + 15' -channel G -fx 'g + 36' -channel B -fx 'b + 60'
Any ideas?
Similar to that: What does "-channel R -fx 'r+0.1'" mean? More red, ok, but how much, 10%?
-fx uses normalized channel values in the range from 0 to 1. So r+.1 is r plus 10%
So you will need to convert your hex components to that range to do something like you are trying to do. But if you add a value that goes beyond 1, it will clip to 1.
However, you cannot process the image as a sequence of steps as you have. You will have to create a separate image for each component and then -combine them together.
However, you are making it harder than you need as I believe you can do:
convert -size 100x100 xc:black -fx "u+#FF0000" red100.png
if you need to use alpha as well, you need to enable the alpha channel first by doing the following:
convert -size 100x100 xc:black -channel rgba -matte -fx "u+#FF000000" red100.png
You can replace your input image in place of my -size 100x100 xc:black
Note also there is a -colorize function. seehttp://
www.imagemagick.org/script/command-line ... p#colorize where you use percent rather absolute color values
