Unlike previous methods, whitebalPR determines the color of illumination by obtaining exact measurements from the photographic scene rather than by estimating it. The new method is based on polarization-difference imaging and discloses new opportunities to measure the color of illumination within digital cameras. It exploits the polarization of light that is specularly reflected at dielectric surfaces.An embodiment is given to integrate whitebalPR into digital cameras.The experimental results demonstrate a very high potential of accuracy and reliability by this approach.