3차원 RGB 색좌표계를 이용한 디지털 카메라 영상의 조명 추정

초록

A digital camera creates an image based on the light intensities incident upon a sensor of a camera. When a given object is photographed by various illuminations, the colors on the resulting image will appear different. It is necessary to estimate the illuminant to reproduce the genuine colors of the given object regardless of illuminations utilized. Estimation of the illuminant is based on the Shafer’s dichromatic reflection model. Most of previous works on this subject utilized two dimensional projection of three dimensional color space. This paper proposes a new estimation method for illuminant that utilizes three dimensional RGB color space. In the proposed method, a three dimensional plane is approximated for each of constant color area on the image. A line common to the approximated planes is calculated. The unit vector representing the calculated line is then utilized for the estimation of illuminant.