Voodoo Extreme heeft een Put Your Ass in the KnowTM artikel gepost over filtering methodes en MIP Mapping. Hier een hap over Bilinear Filtering:
Bilinear filtering is commonplace nowadays. All 3D accelerated hardware supports bilinear filtering. The reasons are plenty. Bilinear filtering is a relatively fast way of smoothing out pixelation (previously referred to as blockiness) while scaling an image. Bilinear filtering, like many other graphic algorithms relies on weighted averages. As it applies to 3D rendering, when choosing the texel to display, take a weighted average of the four pixels surrounding the target location. For example, if we needed the texel at (100.3,100.7) , bilinear filtering would return a pixel with colors which are a weighted average of the texels at (100,100),(101,100),(100,101) and (101,101). This helps smooth out images because, unlike with point sampling, pixels which are bordering largely different colors will not reflect that. (This, in part, causes the aforementioned pixelation.) The images below compare bilinear filtering with point sampling.
