Post-processing shaders work on image data which has already been "rendered" into the screen buffer. The data in this buffer can then be manipulated to produce certain effects, such as lens flare and depth of field.
We provide herewith names and descriptions of post-processing shaders:
"depth of field"
Camera depth of field effects.
"feature-following anti-aliasing"
Anti-aliases pixel-connected features in an image by high-resolution sub-sampling, while propagating further anti-aliasing between pixels only where necessary.
"lens flares"
Lens flare effects.