화학공학소재연구정보센터
Color Research and Application, Vol.34, No.1, 26-32, 2009
Reconstruction of Reflectance Data by Modification of Berns' Gaussian Method
Berns' method for the synthesis of spectral reflectance curve from the tristimulus color coordinates is modified. Firstly, the Gaussian bell shape red primary is replaced with a sigmoidal one to solve the dissimilarity between the spectral curves at the end region of spectrum. Secondly three predetermined Gaussian primaries used ill the original Berns' method are replaced by the adaptive ones which their half-height banwidths vary with the tristimulus values of the desired color. The mentioned modifications are applied for the recovery of the reflectance curves of 1409 surface colors (including 1269 Munsell color chips and 140 samples of Colorchecker SG) and also 204 textile samples. Results of recovery are evaluated by the mean and the maximum color difference values under other standard light sources. The mean as well as the maximum of root mean squares between the reconstructed and the actual spectra are also calculated. The modifications are compared with the common principal component analysis (PCA) as well as Hawkyard's methods for recovery of reflectance factor. Although the PCA leads to the best results, the modifications significantly improve the recovery outcomes in comparison with the original Berns method. (c) 2008 Wiley Periodicals. Inc. Col Res Appl, 34. 26-32. 2009: Published online in Wiley InterScience (www. interscience.wiley.com) DOI 10.1002/col.20458