I am using imagemagick to overlay one image over another with a blending option. I'd like to adjust the overlaying image opacity to about 60%. I would only like to adjust the foreground image, not the merged group. I Currently have:
exec("convert $img_in test_images/test_opacity.jpg -compose screen -composite $img_out");
And I'd like something like this:
exec("convert $img_in (test_images/test_opacity.jpg -opacity 0.6) -compose screen -composite $img_out");
Any help here would be much appreciated.
Use the +level, or -level-color options to adjust the white/black points. This will generally give the mask the effects of "dodging" or "burning"; which, compose Screen will respect.
convert source.jpg \
\( mask.jpg -normalize +level 0,60% \) \
-compose screen -composite destination.jpg
You can also adjust the opacity of the mask by defining an alpha channel with -alpha, -channel & -evaluate. See this question. But this wouldn't work with compose Screen as it's expecting a range between black & white.
convert source.jpg \
\( mask.jpg -alpha set -channel A -evaluate set 60% \) \
-compose screen -composite \
destination.jpg