基于激光点云和近景影像的数字拓片生成方法

Digital rubbings generating method based on laser point clouds and close-range images

传统的拓片制作过程复杂,天气、光照、环境等客观条件都会影响拓片质量,而且手工拓片会对文物本体造成伤害。随着信息化技术的发展,提出了利用数码影像制作数字拓片。由于一般的数码影像是中心投影且没有可量测性,生成的数字拓片也没有实际的应用价值,且基于多张影像的数字拓片还存在图像投影、配准等诸多问题。针对上述情况,本文提出了利用三维激光点云和近景影像生成数字拓片的解决方案:首先利用点云和影像配准生成正射影像,然后采用图像增强的方法消除光照不均,再将图像局部自适应阈值二值化,最后采用图像融合的方法将边缘模糊,生成有传统拓片效果的数字拓片。通过实验证明,本文制作数字拓片的方法具有一定的可行性,且制作的文物拓片具有可量测的优越性,为文物数字化存档和研究提供了更丰富的数据。

The traditional process of making rubbings is not only complex, but also easy to affected by weather, illumination, environment etc, which is easy to cause harm to the cultural relics. With the development of information technology, the production of digital rubbings by digital images is presented. Because the digital images are central projection and no scalability, digital rubbings generated by them can not be measured. Meanwhile the digital rubbings based on images still come up against difficulties such as image projection and registration. The solution to generate digital rubbings by 3 D laser point cloud and close range images is proposed. First we propose a new method of registering 3D laser point cloud with close-range images to generate orthographic images, then we adopt the method of image enhancement to eliminate uneven illumination, and use local adaptive threshold binarization to the image. Finally using image fusion method to generate the traditional digital rubbings with a fuzzy edge. It has been proved that the proposed method of making digital rubbings is feasible, and the production of cultural relics rubbings can be measured, which provides more abundant data for digital archiving and research of cultural relics.