Studies On Texture Mapping, Synthesis And Replacement

Texture means the thing with repetitive patterns and stochastic attribute. It can describe a wide variety of natural phenomena, such as sound, image, video, motion, surface geometry and so on. Texture in computer graphics generally refers to bitmap image. By means of texture technique, it can simulate efficiently the geometry details of the rendered scene, and meanwhile enhance the visual richness. For the wide applications in TV and file producing, digital entertainment, industrial design and virtual simulation, etc., the research on texture has been one of the hottest topics in computer graphic, vision and image processing.In this thesis, some key problems in texture technique: texture mapping, texture synthesis, texture replacement and its application in Non-photo realistic (NPR) rendering are explored, and some new approaches are proposed:(1) Constrained texture mapping. Texture mapping is the process of mapping an image onto the 3D model, it can enrich effectively the reality of the rendered scene. This thesis develops a novel constrained texture mapping method based harmonic maps. It constructs the one-to-one correspondence between each point on the embedded meshes and the one on the texture plane, and gives an analytical solution to this problem. The energy minimization characteristic of the harmonic map preserves the low distortion that may yield in the process of texture mapping. Additionally, a real-time optimization algorithm is introduced for reducing the interaction of constrained texture mapping.The validity of constrained texture mapping is an important issue, this paper introduces a "divide-and-conquer" method that can ensure its validity. The method divides the texture plane as well as the mesh model into corresponding patches based on the specified feature points, and realizes the mapping for each pair of patches. As the pre-process of parametrization is abandoned, the method is executed with high efficiency. The similar idea can be extended to mesh metamorphosis.(2) 3D texture synthesis. Given a texture sample, texture synthesis generates a big size texture that has the similar appearance with the sample. This thesis presents a fast 3D texture synthesis method based on base domain mapping. It first synthesizes texture on the based domain of the input model, which is built adaptively, then maps the result...