# How to achieve this particular screen filter with GLSL?

I know this may be a "short" question, but still here it goes.

I would like to know how to achieve a post rendering effect, that looks like the following image from walking dead series:

I will make the art already fitting the style, but what if I want to make the colors more coherent by adding a color filter such as the one in the picture?

Thanks

• For starters, it looks to me like a lot of the blue has been removed from that image. Mar 15 '12 at 4:53
• Check this stackoverflow.com/a/9402041/160539 Mar 15 '12 at 7:44
• That looks like sepia or exaggerated technicolor: there are a bunch of glsl shaders out there that do this (moddb.com/mods/fxaa-post-process-injector for example). Mar 15 '12 at 15:11

Easiest approach to sepia would be to mix every resulting pixel with sepia color at specified proportion. Pseudocode: Result.rgb = lerp(Color.rgb, Sepia.rgb, Factor); Where Sepia tone may need some tweaking as well (check these variants for example: http://en.wikipedia.org/wiki/Sepia_(color))