Evaluation and analysis for spectral reflectance imaging of human skin

Abstract

We estimated and analyzed the reflectance spectra of human skin at each pixel taken by a multi-band imaging system, and compared it with the RGB three bands imaging system. The multi-band camera can capture more than three bands, and estimate the spectral reflectance using more than three eigenvectors of principal component. In this paper, we implemented a six bands camera system, in which color of the light source is modulated for rapid measurement. The system consists of the RGB three bands digital camera and two different light sources which are strobe light and strobe light with optical filter. We captured the skin twice using each light source respectively. As a result, we could obtain six color bands images. We estimated the spectral reflectance image based on Wiener estimation method, by using the captured multi-band image and the RGB image respectively. Then, we analyzed and evaluated two spectral reflectance images by using principal component analysis. The result shows that that the reflectance spectra estimated from three-band image do not have enough accuracy to analyze the skin color quantitatively.