Fast, High-Quality Line Antialiasing by Prefiltering with an Optimal Cubic Polynomial

Scan-converting lines for raster-based displays is a basic building block of many computer graphics tasks. While many fast line drawing algorithms are known, most produce thin and ´jagged´ lines due to aliasing. Wu´s algorithm includes a crude approximation of antialiasing, which still includes noticeable step edges. Even hardware multisampling cannot entirely eliminate aliasing. Instead, the proper solution is to remove high-frequency components by prefiltering the lines. We improve upon previous ad-hoc filters by deriving the optimal (in the sense of minimizing aliasing) cubic polynomial filter. When combined with our new, optimized variant of the Gupta-Sproull line drawing algorithm, this outperforms Wu´s fast approximation while delivering much higher-quality results.