Page 1 of 1

Turn an image into a background

Posted: 2010-05-26T12:05:16-07:00
by Josh_R
I need to lighten an image to be a background on a document. How do I do that?

Re: Turn an image into a background

Posted: 2010-05-26T12:13:06-07:00
by snibgo
This might do the trick:

convert in.png +level 75%,100% out.png

Re: Turn an image into a background

Posted: 2010-05-26T17:36:29-07:00
by fmw42
Josh_R wrote:I need to lighten an image to be a background on a document. How do I do that?

Lighten it by how much? There are many ways to lighten and image. You can use +level, -brightness-contrast, -gamma, -modulate, -colorize, etc

see http://www.imagemagick.org/script/comma ... ptions.php
and
http://www.imagemagick.org/Usage/color/

Re: Turn an image into a background

Posted: 2010-05-31T19:15:20-07:00
by anthony
It also depends if you want 'black' to remain black. That is just lighten mid-tones.

For generating a light background that is probably not wanted in which case -gamma and image multiply is not a solution.

The +level is probably best in that case. Perhaps with a gamma adjustment as part of the +level.

See IM Examples, Reversed Level Adjustments
http://www.imagemagick.org/Usage/color/#level_plus
With Gamma...
http://www.imagemagick.org/Usage/color/#level_gamma