"Blending algorithms for overlapping projected image boundaries", SDS International, R&D for US Military , 10/2000.
This research attempted to find mathematical functions that decrease the factoring weight associated with red, green, blue and alpha color values as a function of the overlapping region distance. Blending combines the incoming fragment's red, green, blue, alpha values with the ones stored in the framebuffer at the incoming fragment's location. The functions that exhibited the desired factoring weights for the color components at the pixel level, were the logarithm function of the overlapping width and the inverse exponential function of the same input. Within the OpenGL framework, the glBlendFunc(src, dest) function was used, where the source and destination arguments specify how the red, green, blue, and alpha source and destination blending components are computed.