Digital restoration of mural paintings from late Tang tomb M1373 in Xi’an based on hyperspectral analysis and image interaction processing

In this study, we take the mural of the Late Tang M1373 tomb unearthed in the eastern suburbs of Xi’an, Shaanxi Province in November 2022 as the object, focus on the insufficient consideration of color authenticity in the current use of image processing for mural visual restoration, as well as the lack of systematic mural color and visual restoration method based on hyperspectral images. A improved spectral recognition method of mural pigment based on fusion spectral analysis and mixed spectral modeling was used in real scene; a virtual restoration method for mural pigment colors based on bandpass energy integration, pseudocolor display and color space correction was proposed; in addition, a integrity restoration of painting patterns including draft line enhancement and human-computer interaction image processing was used in the real mural color restoration. The experimental results show that the mural uses traditional mineral pigments such as ochre, earth yellow, mineral green and carbon black for its red, yellow, green and black pigments, and the accuracy rate of this method is higher than 97% in simulation experiments with noise of %4 spectral amplitude. Meanwhile, the richness of painting color of the restoration results is significantly improved compared to the original color photos, especially, the new method with color space correction is significantly better than the method without color space correction in texture.