基于融合光谱分析的墓葬壁画颜料色彩虚拟修复方法研究

墓葬壁画是一种重要的彩绘文物,对其进行揭取搬迁并加固修复是目前主要的保护方式。而在揭取搬迁时,对壁画绘画内容和颜料进行数字化记录及特性分析,是后续壁画表层合理修复的重要依据。光谱成像技术作为一种属性与视觉同步感知的信息探测手段,可以用于壁画表面颜料层的高维信息记录与材质属性分析;同时,利用高光谱伪彩色显示技术可以实现颜料色彩的虚拟复原。基于此,提出一种基于融合光谱分析与带通能量积分的壁画颜料色彩虚拟修复方法,并利用采集的颜料光谱数据、壁画高光谱成像数据与模拟真实场景下的混合颜料光谱数据进行壁画颜料识别与色彩虚拟复原实验。实验结果表明,对于选取的唐墓壁画上的红、黄、蓝、绿四种颜料,其融合光谱识别结果是:武惠妃墓的红色颜料为朱砂/银珠、韩休墓的黄色颜料为石黄/雌黄、武惠妃墓的蓝色颜料为石青/青金石、韩休墓的绿色颜料为石绿的匹配度最大;同时,基于上述识别结果,得到了纯色复原和壁画基底绘制复原的壁画颜料色彩虚拟复原结果,可以为壁画实体修复提供颜料层视觉修复的参考依据。上述研究成果在壁画保护及活化利用领域具有重要的创新示范意义。

Research on a method for virtual restoration of the colors of tomb mural pigments based on spectral fusion analysis

Tomb murals are among the most important painted cultural relics, and removal, reinforcement and restoration are main protection methods for them at present. During the removal, the digital recording and characteristic analysis of mural painting contents and pigments is an important basis for the subsequent reasonable restoration of the mural surface. The spectral imaging technology, as a means of information detection for synchronous perception of attributes and vision, can be used for the high-dimensional information recording and material attribute analysis of the pigment layer on mural surfaces. In addition, virtual restoration of pigment colors can be realized using the hyperspectral pseudo-color display technology. Based on this, a method for virtual restoration of the colors of mural pigments based on the spectral fusion analysis and band-pass energy integration is proposed and experiments on mural pigment recognition and virtual restoration of colors were carried out using collected pigment spectral data, mural hyperspectral imaging data and mixed pigment spectral data in simulated real scenes. According to the experimental results, for the red, yellow, blue and green pigments on the selected mural from Tang tombs, the spectral fusion recognition demonstrated that the red pigment from the tomb of Imperial Concubine Wu Hui was cinnabar/silver vermilion, the yellow one from the tomb of Han Xiu was orpiment/bezoar, the blue one from the tomb of Imperial Concubine Wu Hui was azurite/lazurite, and the green one from the tomb of Han Xiu was malachite. In addition, based on the above results, virtual restoration of mural pigment colors of pure color restoration and mural substrate rendering restoration were obtained. These results could provide a reference of the visual restoration of pigment layers for the physical restoration of murals. The above research results have important innovative and exemplary significance in the field of mural heritage protection and activation utilization.