Research On Key Technology Of Texture Reconstruction And Organization For Cultural Relics In Museums

Cultural Relics are the heritages with historical, art and scientific values. The3D digital reconstruction, which is an important method to record, preserve, inherit and appreciate the cultural relics, is now becoming more significant and challenging.The3D reconstruction for targets includes two steps of geometric and texture reconstruction. Aiming at the texture reconstruction, this paper proposed a complete solution for the cultural relics in museums. The input data of our method is the point clouds with synchronous images from structure-light scanning system and the high resolution images from SLR cameras. Our method has the merits of high quality, high fidelity and high efficiency, in which the major contributions include:1.3D surface reconstruction from scanning point clouds. Among the general-used methods in3D measurement, structure-light scanning system is one of the most stable ways to gain the dense and uniform points from objects’surface. But as the final result of geometric reconstruction should be the mesh model, it needs to construct the triangular mesh from the point clouds. After summarizing the existing surface reconstruction methods, we chose7approaches to carry through the real data experiments. And finally, due to the superiority in handling noise and non-uniform samplings, Poisson surface reconstruction method is chosen to do geometric reconstruction for the point clouds from structure-light system.2. The automatic registration between high resolution images to geometric model. Since the structure-light system is still an image-based measurement method, it can capture a synchronous image during one scan. These synchronous images can be registered easily to the final geometric model along with the point clouds alignment. First, we regard these synchronous images with known parameters as the reference. Then the corresponding point pairs between high resolution images and geometric model are calculated through image matching and ray casting techniques. At last, the exterior parameters of high resolution images are accurately estimated through robust resection. The whole process is automatic and efficient, and experiments proved our method.3. Seamless texture mapping from multi-view images. After registering sufficient high resolution images, seamless texture mapping is another challenge, due to the inevitable differences between images in color, illuminance etc. First, we reviewed the existing methods in removing texture seams. Then we proposed a new photometric processing method of face-wise Poisson blending for removing photometric discrepancy on seam-lines, which is based on standard Poisson image editing approach combined with color transfer techniques. Compared with the existing methods, theoretical analysis and experiments proved that our method is more appropriate for3D seamless texturing.4. Optimizing texture maps and simplifying the texture model. As the development of hardware, the density of scanning points and the resolution of images become increasingly higher. For reducing the redundancy of texture maps, we reformed the existing texture packing methods by texture block merging. And then, we proposed a complete and high quality solution to resampling the texture for the simplified geometric model from the original texture maps. Our method not only enriches the simplification methods for texture models, but also shows advantages in comparison to the existing methods.5. The application of texture reconstruction. We developed a set of software for texture reconstruction, and do a lot of3D reconstruction for cultural relics in museums, art and crafts etc. And for the exhibition on mobile platforms, we developed an iPad App based on the OGRE3D graphics engine. At last, we proposed a true-ortho photo generation method based on the result of texture reconstruction.