视觉测量中圆形标记点的高精度定位  

A new method for accurate location of concentric circles in visual measurement

作　　者：陈新禹[1] 马孜[1] 胡英[1] 陈余庆[1] 毕丰隆[1] 

机构地区：[1]大连海事大学自动化研究中心,辽宁大连116026

出　　处：《光电子．激光》2013年第8期1524-1528,共5页Journal of Optoelectronics·Laser

基　　金：国家科技重大专项基金(2009ZX04001-021);国家自然科学基金(61203082)资助项目

摘　　要：为了消除透视变换过程中产生的圆心偏差,基于交比不变和配极对应原理,提出了一种利用同心圆目标精确定位圆心在图像中的真实投影点的方法。首先介绍相关的理论基础,然后详细介绍了算法的实现步骤,最后通过仿真和真实图像实验验证算法的正确性以及影响圆心定位精度的因素。实验结果表明,本文算法可以稳定、准确地获取圆形目标的真实投影点,且投影点的定位精度要优于0.2pixel,相较椭圆拟合法具有明显的精度优势;同时,本文算法仅包含简单的线性运算,因此具有较高地运算效率。由于本文算法对摄像机和同心圆的物理参数无任何要求,因此具有应用广泛的特点。In order to eliminate the deviation of the projection center of a space circle generated by perspective transformation,a novel method based on the principles of cross ratio and pole-polar relationship is proposed in this paper to locate the real projection center precisely using concentric circles. Firstly,the basic principles are introduced briefly,then the detailed procedures to locate centers are addressed,and lastly the accuracy of location and the impact factors of the accuracy are analyzed by experimental meth- ods with simulated and real images. Experimental results indicate that the method can obtain the real projection center of a space circle accurately and stably, and the positioning precision is always better than O. 2 pixel even under very harsh conditions,which has obvious advantages compared with the direct ellipse fitting method Besides,only simple linear computation is involved in our method, so it also has computational efficiency. Furthermore,the method can be employed with high generality due to any in- formation about camera intrinsic or extrinsic parameters is not required and the physical models of the concentric circles are not necessary either. It concludes that our new method is valuable in theory and practice for machine vision,visual measurement and some other fields.

关 键 词：机器视觉 圆心定位 交比不变 配极对应 同心圆 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]