TRANSFORMING OBJECT-SURFACE TEXTURE DATA INTO A TEXTURE MAP

Some range scanning methods, including stereopsis, are capable of meas uring not only an object's shape but also its surface texture. General ly, measured shape data are expressed as a polyhedron whose faces are triangles, and object-surface texture is represented by the set of col or data for each of the vertices of the triangles. However, such data expression are not suitable for the creation of computer graphics imag es, because conventional texture mapping proceeds from images (commonl y referred to as texture maps.) Proposed here is an algorithm that tra nsforms object-surface texture data into a texture map. First, the alg orithm reduces the number of triangles in the polyhedron while preserv ing almost all the color data that the polyhedron originally contained . Then, the algorithm unfolds the simplified triangle mesh into a plan e, and generates a texture map from the unfolded triangle mesh. The al gorithm can preserve the whole texture of an object, no matter how com plex its shape, an advantage over the conventional cylindrical approac h for texture expression. Furthermore, since almost all color data are retained, a realistic object image can be created with only a relativ ely small number of triangles.