Design And Implementation Of Highly Precise Capture Technique And Equipment For Large-area Paintings And Calligraphies

Digital capture and storage for the ancient paintings and caligraphies has always been an important part of the computer aided relic protection, and is of great practical meaningful value. One major difficulty in that field lies in the large-area paintings and calligraphies' digital capture. In this paper, we analysed the current large-scale capture equipment, most of which are scanners. We then proposed and implemented a capture system that is based on partly picture-taking and picture combination. Since the area sometimes is very large, and the required precision is pretty high, our system take the relatively small-area pictures one by one, and then combine them in a precise way.Our system is designed particularly for the large-area paintings and calligraphies.The largest area can be 4m*8m,so it is very necessary to propose a steady,reliable moving control system,which can be precisely controlled to move and take pictures in every small area.Our moving system in this paper is based on the Mitsubishi motor.The driving control is based on the Mitsubishi Programmable Logic Control(PLC).Based on the control system,we implemented the automatic picture-taking and transferation system.Using that system,we successfully captured and transferred the pictures from the remote camera and stored them in the computer.In this paper we also did the camera calibration process.Using the calibration result,we did the perspective aberration rectification.After the pictures are rectified,we did the combination in an automatic and precise way.Our system has been made into practical use,including the Dunhuang calligraphies.The largest precision can be up to 600 ppi,while the largest printing precision can be 3600 ppi.The result of the large-area paintings and calligraphies is satisfactory.