Legacy ImageMagick Discussions Archive

fmw42 wrote: 2018-07-06T16:51:18-07:00 In Unix syntax that would be:

Code: Select all

magick \
in.png \
\( +clone -alpha extract -fill "gray(25%)" \
-draw "rectangle 0,0 %[fx:w-1],%[fx:h*0.3]" \
\) \
-alpha off -compose CopyOpacity -composite \
out.png

Yes, that is what I was looking for! Thank you.

What version of IM, on what platform? I'll assume v7 on Windows CMD.

Assuming you want to set opacity in that area to 25% (so we don't care what it used to be):

magick ^
in.png ^
( +clone -alpha extract -fill gray(25%) ^
-draw "rectangle 0,0 %[fx:w-1],%[fx:h*0.3]" ^
) ^
-alpha off -compose ...

Note: I edited the original question to provide the relevant details on IM version and platform.


$ uname
Linux
$ convert -v
Version: ImageMagick 7.0.8-5 Q16 x86_64 2018-07-05 https://www.imagemagick.org



Here is an example input: https://thumb.ibb.co/fRm0rd/input.jpg

And here is an example ...

Assume a color image. I would like to give the top bar of the image (i.e., a rectangular section with a width equal to the total width of the image) a moderately transparent gray color, such that a regular black text can be placed onto and easily read from it, irrespective of the actual image color ...