I was playing "Silent Hill: Home Coming" for a couple of days and was interested in effect (filter) that is applied to final image to make it dark and noisy. I have done a surgical operation for the game to understand how the effect works and finally got it and implemented a sample program using OpenGL that demonstrates it.
The sample program as well as shaders code is under GPL, so they can be freely used in games/engines or wherever you want.
Before the effect:
After the effect:
To be honest, static images above cannot show this pretty random, noisy effect in a good way, so if you want to look at it better you can check binaries below.
Links
Investigation & Explanation
Linux binaries
Windows binaries
Sources