3D INFORMATION RESTORATION OF THE DIGITAL IMAGES OF DUNHUANG MURAL PAINTINGS

摘要

Mogao Grottoes in Dunhuang are famous for its profound content and perfect art in the world. But various kinds of damage coming from mankind or nature brings Mogao Grottoes a lot of disease, which makes this large-scale historical cultural heritage in the world degraded and damaged constantly. It is very urgent to find out all kinds of measures to protect it. The processes to restore 3D information of the mural paintings by means of the digital close-range photogrammetry and computer-based image processing technology were expounded in this paper in order to digitally preserve the mural paintings in the original style. The uniform coordinate system of the Grottoes was set up, and the mural paintings of the Grottoes were close-range photogrammetried, furthermore, the films obtained from the close-range photogrammetry were scanned as digital images by a higher resolution scanner. The assistant spatial coordinate of the mural paintings in the each wall was then set up by the coordinate transformation. On the basis of this, by means of model orientation, kernel line resampling, image matching, the orthoimages of the mural paintings were created and the 3D information was restored finally. The processing results of the mural paintings showed that the residual error of the absolute orientation of all control points reached the millimeter accuracy level, and that the middle error of the digital surface model of the mural paintings. That is, the geometric correction of the images data of the mural paintings reached the millimeter accuracy level. It indicated that the 3D information of the mural paintings could be accurately restored by the close-range photogrammetry and computer-based image processing technology in order to protect and digitally restore the mural paintings and statues of Mogao Grottoes in Dunhuang forever. At the same time, it provided for us a new method and thought for relics protection, and new measures for the ancient costly relics protection, restoration and research.