Approximation of Material reflectance Spectrum by Finite Basis function Expansion

• Main Authors: Na-Tai Yeh, 葉鈉泰
• Other Authors: Wei-song Lin
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/29779263450560504040

碩士 === 國立臺灣大學 === 電機工程學研究所 === 90 === Approximation of reflectance spectrum by the linear combination of basis functions is widely used in the study of color constancy and color reproduction. However, performance of the basis functions depends on the abundance of the data sets on which the basis functions are derived. The basis functions currently available in the literatures are found not able to well approximate natural material’s surface reflectance spectra. The required number of basis functions for fine approximation is another problem to be answered. This paper collects and analyzes hundreds of the surface reflectance spectra of different material types. Using the principal component analysis, the basis functions are obtained. These functions are applied to approximate the reflectance spectra of some natural materials and compared with previous ones. It is found that to optimize the approximation, the basis functions should be chosen in accordance with the categories of the target materials under observation. An easy way to achieve the adaptation is to establish a library of basis functions for variant applications.