数字图像的自动白平衡算法设计与FPGA实现  

Design and FPGA Implementation of Automatic White Balance Algorithm for Digital Images

作　　者：鲜玲霞 何彦穅 夏欢 田飞 XIAN Lingxia;HE Yankang;XIA Huan;TIAN Fei(College of Mechanical and Electrical Engineering,Chengdu Univ.of Tech.,Chengdu 610059,China)

机构地区：[1]成都理工大学机电工程学院,成都610059

出　　处：《自动化与仪器仪表》2023年第12期5-8,共4页Automation & Instrumentation

摘　　要：在不同的色温光照下,图像传感器接收到的图像颜色与实际有着不同程度的偏差,需要进行偏色校正处理。针对完美反射法在过度曝光下偏色校正会失效,以及灰度世界法在画面出现了大量的单一色彩时偏色校正效果较差的问题,提出了一种改进完美反射法和改进灰度世界法相结合的自动白平衡算法,通过两个改进算法分别产生类白点与平均值来计算增益系数,从而完成对图像的偏色校正。通过FPGA实现该算法,可以在保证高效和实时的同时,还能占用少量的硬件资源。经过测试结果分析,提出的自动白平衡算法在三个不同场景下将色差均值降至1左右,比原始图像的色差均值小很多,有较好的白平衡处理效果。Under different color temperature light,the image color received by the image sensor has different degrees of deviation from the actual color,which needs to be corrected.In order to solve the problem that perfect reflection method will fail in color shift correction under overexposure,and gray world method has poor color shift correction effect when a large number of single colors appear in the picture,an automatic white balance algorithm combining improved perfect reflection method and improved gray world method is proposed,and the two improved algorithms are used to generate white point values and average values respectively to calculate the gain coefficient.Thus complete the image shift correction.Using FPGA to implement the algorithm,it can not only ensure high efficiency and real-time,but also occupy a small amount of hardware resources.After analysis of test results,the proposed automatic white balance algorithm reduces the mean color difference to about 1 in three different scenes,which is much smaller than the mean color difference of the original image,and has a good white balance processing effect.

关 键 词：自动白平衡算法 偏色校正 完美反射法 灰度世界法 FPGA 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]