[OPTICAL REVIEW Vol. 8, No. 6 (2001) 444-450]
High-Fidelity Image Reproduction Using Angular Distribution of Reflected Spectral Intensity
Masaru TSUCHIDA1,3,*, Yuri MURAKAMI2,3, Takashi OBI1,3, Masahiro YAMAGUCHI1,3 and Nagaaki OHYAMA2,3
1Imaging Science and Engineering Laboratory, 2Frontier Collaborative Research Center, Tokyo Institute of Technology, 4259, Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan, 3Akasaka Natural Vision Research Center, Telecommunications Advancement Organization of Japan, 2-17-2, Akasaka, Minato-ku, Tokyo, 107-0052 Japan
(Received May 30, 2001; Accepted September 17, 2001)
A method to reproduce images of an object under various observation conditions is presented. In this method, a series of multispectral images is captured by rotating the object under a point light source of which spectral power distribution and the position are known. The captured images are decomposed into diffuse and specular reflection component images based on the dichromatic reflection and the Lambertian models. Next, the incident angle of the illumination light and the angle between viewing direction and regular reflection are calculated based on observation geometry. Finally, the image under observation geometry is synthesized using the light-ray rearrangement technique. The experiments are carried out using two-dimensional objects, leather and fabric. Most of the synthesized images are shown to be the same as the images actually captured under the assumed illumination geometry, even if the object has complex reflection like fabric for which it is difficult to apply the reflection model used in computer graphics.
Key words : color, gloss, multispectral image, observation conditions, the dichromatic reflection model, light-ray rearrangement