Using a flash/no-flash image pair, we propose a novel white-balancing technique that can effectively correct the color balance of a complex scene under multiple light sources. In the proposed method, by using multiple images of the same scene taken under different lighting conditions, we estimate the reflectance component of the scene and the multiple shading components of each image. The reflectance component is a specific object color which does not depend on scene illumination and the shading component is a shading effect caused by the illumination lights. Then, we achieve white balancing by appropriately correcting the estimated shading components. The proposed method achieves better performance than conventional methods, especially under colored illumination and mixed lighting conditions.

In lowlight conditions, images taken by phone cameras usually have too much noise, while images taken using a flash have a high signal-noise ratio (SNR) and look unnatural. This paper proposes a novel imaging method using flash/no-flash image pairs. Through transferring the natural tone of the former to the latter, the resulting image has a high SNR and maintains a natural appearance. For realtime implementation, we use two preview images, which are taken with and without flash, to estimate the transformation function in advance. Then we use this function to adjust the tone of the image captured with flash in real time. Thus, the method does not require a frame memory and it is suitable for cell phone cameras.