Photo-realistic texture mapping for voxel-based volume data

In computerized image and graphic applications, texture mapping is one of the most commonly used methods to improve the realism or to enhance the visual effect of object rendering without too much increase in computational complexity. In conventional texture mapping, a three-dimensional (3D) object has to be transferred to the polygonal structure, and then mapped with a texture or photographic image. However, it is usually computationally expensive to transfer the original data in voxels to polygons, and is even more complex to map the 2D texture image onto the 3D polygonal structure. Even though the computation is huge, the polygonal structure is not efficient in preserving the internal information of volume data. Because most volume data acquired by medical imaging devices or 3D scanners are in voxel format, it is more appropriate to handle these data directly in voxel format. In this paper, we propose a new texture mapping method based on chain-coding flattening to handle the voxel-based data directly. Therefore, the computation is reduced significantly and the internal information can be utilized and preserved thoroughly. The method flattens a 3D object surface onto a 2D plane and then uses 2D warping technique to generate the correspondences between the object surface and the texture image. Therefore, polygonal transformation required in the conventional approach is no longer necessary and texture mapping is handled with inexpensive 2D computation. Experimental results have shown the effectiveness and efficiency of the proposed algorithm.