离焦成像对面积测量的影响及误差修正  

Effect of Defocused Image on Area Measurement and Error Amendment

作　　者：沈满德[1] 张敏[2] 张法全[3] 陈良益[2] 

机构地区：[1]武汉科技学院电子信息工程学院,武汉430073 [2]中国科学院西安光学精密机械研究所,西安710119 [3]郑州轻工业学院电气信息工程学院,郑州450002

出　　处：《光子学报》2009年第5期1240-1244,共5页Acta Photonica Sinica

基　　金：国家自然科学基金(60337030)资助

摘　　要：针对机器视觉中存在的离焦现象,采用理论与实验相结合的方法分析了离焦成像对面积测量的影响.实验表明,当离焦量(物面偏离对准平面的距离)为10mm时,面积相对误差达31.3%.根据图像最大梯度值与离焦量之间的关系提出了一种误差修正的方法.首先标定图像最大梯度值与离焦量之间的关系,然后求待测图像的最大梯度值,由最大梯度值求出离焦量,最后根据离焦量对图像面积进行修正.结果表明,当离焦量小于10mm时,经修正后图像面积相对误差小于3.8%.Phenomenon of defocus in machine vision, the effect of defocused image on aTo therea measurement was analyzed by the method of theory and experiment. The results of experiment show that the relative error is 31. 3% when the object plane deviates 10 mm from conjugate plane. A method of amendment error was developed according to the relation between maximal image gradient and defocusing amount. The relation between maximal image gradient and defocusing amount was calibrated. The maximal gradient of image was calculated. The defocusing was amended according to the defocusing amount. than 3.8% ,when the defocusing amount is within amount was deduced. And, the area of defocused image After amendment,the relative error of image area is less

关 键 词：离焦成像 图像梯度 图像面积 误差修正 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]