AXAA: adaptive approximate anti-aliasing

Abstract

Post-processing anti-aliasing algorithms are widely used now for real-time rendering because of their simplicity, performance, and suitability for deferred shading. Fast approximate anti-aliasing (FXAA) [Lottes 2009] is the fastest method among them, so many games support FXAA to get anti-aliased images. However, FXAA can easily lose texture details and text sharpness due to its excessive blurring. To alleviate those problems of FXAA, we present adaptive approximate anti-aliasing (AXAA). Our approach adds three contributions to FXAA in order to avoid unnecessary filtering. First, we stop further anti-aliasing processes if the current pixel or its neighbors are judged as pixels on already filtered textures or fonts. Second, we try to maintain thin lines as much as possible in order to avoid blurring fonts and lines. Third, for higher performance, we adaptively set the search range of each pixel according to luma contrast. Our experiments show that AXAA provides significantly better image quality than FXAA, in terms of texture, text, and geometry details. Nevertheless, processing overhead of AXAA is still similar to that of FXAA.