In this chapter, we present a series of simple and effective methods to perform high quality texture filtering on modern GPUs. We base our methods on the theory behind the elliptical weighted average (EWA) filter [Greene and Heckbert 86]. EWA is regarded as one of the highest quality texture filtering algorithms and is used as a benchmark to test the quality of other algorithms. It is often used in offline rendering to eliminate texture aliasing in the extreme conditions mentioned above, but due to the high computational cost it is not widely adopted in real-time graphics.