Design and hardware implement of automatic white balance based on chromaticity difference

This paper tries to solve the problem that different degrees of color cast will be presented when collects images from various directions in the same circumstance by using the system of Multi-vision. An automatic white balance algorithm based on the chromaticity difference is proposed, in which adopts the color difference formula CIE 1976Lab, comparing the Chromatic difference with threshold value of adjacent pixels and removing the interference pixels, the color temperature will be more accurate. And using integer multiplies and shift operation instead of floating-point arithmetic, the transformation from RGB color system to XYZ color space is optimized. This paper will start with description of algorithm principles. Following this, Chromatic difference white balance module will be built combining with DSP builder, and using Signal Compiler, the algorithm will be implemented by transplanting codes into FPGA. At last, Experimental results show that the proposed method can get a comparatively good color white balance effect by applying this algorithm into the latest Multi-vision system of panoramic stereo sphere vision.