Abstract
Texture mapping is applied extensively in modern computer graphics applications. Conventionally only high end graphics workstation can provide texture mapping capability, nowadays non-expensive personal computers (PCs) with medium level 3D graphics card can achieve texture mapping in interactive time. However, the alias problem in texture mapped images greatly affect the visual quality, especially in complex scene with textures of small grain size. To cope with this problem, the mipmap algorithm is a common solution. But due to approximate texture parameterization and mpimap level calculation, especially in deep perspective projection, may result in annoying artifacts in texture mapped pictures. In this study, we propose an improved algorithm to eliminate these artifacts and generate correct mipmapped images. The basic idea of our algorithm is to redesign the texture parameterization function, and find the inverse texture area by its bounding quadrilateral. Then the level in mipmap is decided by the pixel area ratio between texture space and screen space. We also suggest a new alternative for pyramid structure. With the acceleration of hardware pixel scaling function, pyramid can extend mipmap resolutions by dynamically generating suitable level of mipmap-textures which generally result in a better texture mapped image. The experiment result of our algorithm shows that our method not only generates correct texture mapped image but also preserves a fine grain quality of the texture image without distortion.