How to use summed area table algorithms in OpenGL?

Every freind:
I encounter a difficult in OpenGL. I want to use the way of summed-area tables in texture mapping. I know there is mipmap filter as texture mapping. but at present I think over using summed-area tables algorithms to perform maping. Who can tell me how to do this. If send me source code of realizaon this algorithms in OpenGL. Thank a lot! a lot. My email adress :

Because generating summed area tables is more a sequential than a parallel operation, it’s quite slow. You have to flush the pipeline once for every row and column of your image. I’ve been thinking of a method that might speed it up, but I haven’t tested it yet.