An efficient spectral-based calibration method for RGB white-balancing gains under various illumination conditions for cell-phone cameras

Significant sensitivity variations among cell-phone camera modules have been observed. As a result, for an effective and reliable white balancing, per-module RGB-ratios calibration/estimation under various illumination conditions is required. Herein, a new technique is proposed which minimizes/simplifies RGB-ratios calibration/estimation process. The proposed method could be based on either direct image capture or spectral numerical processing--the latter is shown to be more flexible and accurate.