改进的LoG边缘自动白平衡算法*

针对物体在有色光源照射下呈现偏色的现象，提出一种改进的LoG边缘自动白平衡算法。该算法在YCbCr空间的Cb和Cr分量上同时利用LoG算子提取边缘，利用LoG边缘具有零交叉特性直接得到边缘两侧的像素。为了避免占主导的彩色纹理造成干扰，利用白色区域的偏色信息进行边缘抑制。利用得到彩色边缘对原图的偏色进行有效的估计，最后计算三颜色通道的增益并进行白平衡。对大量图片进行了实验，结果表明该算法对不同色光照射下的图像均能很好地进行白平衡，同时与多种白平衡算法的对比实验表明该算法适应面广，性能良好。

Improved method of automatic white balance based on LoG edge detection

Aiming at the color offset phenomenon of object under colored light source,the paper presented an improved method of automatic white balance based on LoG edge detection.This method detected the image edges by LoG operator on Cb and Cr of YCbCr color space,then obtained the pixels at both sides of edges using zero-crossing characteristic of LoG edges.To avoid the interference caused by magistral color textures,inhibited the edges by color offset information of white region.After effectively estimating the color offset of original image using obtained color edges, it could compute the three color channel gains and do white balance.A lot of pictures were experimented. Rresults indicate that the method can do white balance with pitures taken under various colored light.In comparison with other white balance method, the method shows more adaptation and good performance.