Re: Create fainted image for background

In IM, there is a similar function called -level or +level. You can 
shift by raw values or by percent. I usually use percent.

-level stretches the histogram and +level compresses the histogram

see
http://www.imagemagick.org/Usage/color/#level
http://www.imagemagick.org/Usage/color/#level_plus

You can shift either the low (black) side or the high (white) side or both.

There is also an automatic stretch function -auto-level

The level functions adjust in a linear manner.

You can adjust in a non-linear manner using -gamma, -evaluate pow, 
-sigmoidal-contrast.

see

http://www.imagemagick.org/Usage/color/


If you just want to mix some color with your image, you can do

convert image -fill somecolor -colorize XX% result

see

http://www.imagemagick.org/Usage/color/#colorize


I also have some unix shell scripts that you might want to look at:

see autocolor, autogamma, autolevel, bcimage, clip, exposure, curves, 
plm, omnistretch, redist, stretch

http://www.fmwconcepts.com/imagemagick/index.html


Fred