Spectral image acquisition, analysis, and rendering for art paintings

Abstract

We propose a technique for viewpoint and illumination-independent digital archiving of art paintings in which the painting surface is regarded as a 2-D rough surface with gloss and shading. Surface materials like oil paints are inhomogeneously dielectric with the dichromatic reflection property. The procedure for total digital archiving is divided into three main steps: acquisition, analysis, and rendering. In the first stage, we acquire images of a painting using a multiband imaging system with six spectral channels at different illumination directions. In the second stage, we estimate the surface properties of surface-spectral reflectance functions, surface normal vectors, and 3-D reflection model parameters. The principal component analysis suggests that the estimated spectral reflectances have the potential for high data compression. In the third stage, we combine all the estimates for rendering the painting under arbitrary illumination and viewing conditions. We confirm the feasibility of the proposed technique in experiments using oil paintings.