Multispectral photography investigation technology has previously been used to reproduce the contents of obscure murals and to analyze the use and distribution of the pigments in these murals. As for the Mogao cave murals, a Database of the Mogao Cave Mural Pigments Multispectral Photography Image Standards has been established by a rigorous system of selection and verification from the captured multispectral images of the 24 known types of painting materials established by previous research results. Based on comparative terms, one can obtain the class and distribution status of pigments of Maogao grotto murals through analysis conducted by trained professionals comparing and analyzing the images of the murals captured under spectral conditions aligned with the pigment spectrum from the database. Individual differences in the perception of colors, however, is likely to lead to subjective inconsistencies, recognition difficulty, low precision etc., and is not a process untrained individuals can complete to satisfaction. This study adopts the multispectral photography system to develop a multispectral digital image identification system for mural pigments based on the color data obtained from multispectral images. The process begins by selecting RGB values of the target pigment from obtained multispectral images of wall paintings and converting them to HSV color space. By automatic querying, the most numerically similar HSV color values are then matched with pigment values from the multispectral image database, thus providing a scientific identification of pigment category to a high degree of accuracy and efficiency that avoids the problems related to subjective manual comparison.
