Real-time auto white balancing for digital cameras using discrete wavelet transform-based scoring

In digital cameras, the process of making white colors to appear as white under different illuminants is referred to as auto white balancing. This paper presents an auto white balancing algorithm, named discrete wavelet transform (DWT)-based scoring, which is computationally much more efficient than the original auto white balancing scoring algorithm. Its computational efficiency is thus utilized to achieve a real-time implementation on an actual digital camera platform. The platform consists of the Texas Instruments TMS320DM320 programmable processor which is specifically designed for the digital camera market. The real-time implementation results indicate the effectiveness of this algorithm in identifying a scene illuminant as compared to the widely used gray-world auto white balancing algorithm.