Re: Making all colors in an image lighter by a certain percentage

Fred Weinhaus <[email protected]> Mon, 18 Apr 2011 17:49:20 -0700
Newsgroups gmane.comp.video.image-magick.user
Message-ID <p06240805c9d28c447f36@[192.168.1.2]>
>Anthony wrote:
>
>-level 0,80%  is actually equivalent to -evaluate multiply 80%


I believe he is correct. However, I think using either affects not 
only the brightness but also the contrast.

So probably what you need is either:

-evaluate subtract 20%

or use

-brightness-contrast

and just adjust the brightness


Fred