Precise Estimation of Painting Surfaces for Digital Archiving Tetsushi Tanimoto, Takahiko Horiuchi, and Shoji Tominaga Graduate School of Advanced Integration Science, Chiba University Chiba, 263-8522 Japan t_tanimoto@chiba-u.jp, {horiuchi,shoji}@faculty.chiba-u.jp Abstract. This paper proposes a method for precisely estimating the surface properties of oil paintings for digital archiving. The surface prop- erties include surface height information, surface spectral reflectance, and reflection model parameters. We use mainly a multiband imaging system and a high-resolution RGB camera, and use locally a spectrometer and a laser-scanning meter for precise surface measurement. First, we com- bine the estimated surface-spectral reflectances in high resolution from the multiband system and the measurements in low resolution from the spectrometer. Second, we combine the estimated surface height in high resolution from the RGB camera and the measurements in low resolu- tion from a laser-scanning meter. Third, we develop a region dependent rendering algorithm where appropriate reflection parameters are deter- mined for classified regions. All estimates of the surface properties are combined for rendering realistic color images of oil paintings. The fea- sibility of the proposed methods is shown in experiments using real oil paintings. Keywords: Color image rendering, precise color reproduction, oil paint- ing, surface property estimation, digital archivingt. 1 Introduction The old type of digital archiving of art paintings was called “viewpoint and illumination-specific digital archiving” [1], which achieved a pleasing record only for a single viewpoint and for a limited range of materials with minor surface height. The surface of an oil painting is not smooth, but rough. Because the surface material consists of a thick oil layer, strong glosses or specular highlights appear on the surface. Therefore, “viewpoint and illumination-independent dig- ital archiving” is required for rendering art paintings at different viewpoints and illuminations. The authors have been working on development of techniques for viewpoint and illumination independent digital archiving of oil paintings [2]-[3], in which the painting surface is regarded as a 2D rough surface with gloss and shading. The procedure for total digital archiving is divided into three steps: acquisition, S. Tominaga, R. Schettini, and A. Tr´ emeau (Eds.): CCIW 2013, LNCS 7786, pp. 171–183, 2013. c  Springer-Verlag Berlin Heidelberg 2013