Noriko Nagata, Toshimasa Dobashi, Yoshitsugu Manabe, Teruo Usami and Seiji Inokuchi,
Modelling and Visualization for Pearl Quality Evaluation
Simulator,
In The 10th Scandinavian Conference on Image Analysis,
Lappeenranta, Finland, pp. 165-172, June 1997.Visual simulation using CG and VR has attracted wide attention in machine vision. This paper proposes a method of modeling and visualizing pearls that will be the central technique of a pearl quality evaluation simulator. Pearls manifest a very specific optical phenomenon that is not dependent on the direction of the light source. To investigate this feature, we propose a physical model for multilayer film interference considering the multiple reflection in spherical bodies. The rendering algorithm has been configured from such representations of physical characteristics as interference, reflection and texture which correspond respectively to the sense of depth, brightness and grain that are the main evaluation factors obtained from psychological experiments. Further, portions of photos of real pearls and the images generated by the present method were evaluated based on a scale of psychological evaluation of ``pearl-like quality'' demonstrating thereby that not merely the generated images as a whole but the respective parts of images can present such a pearl-like quality.