中国组织工程研究

中国组织工程研究 ›› 2012, Vol. 16 ›› Issue (17): 3156-3159.doi: 10.3969/j.issn.1673-8225.2012.17.027

• 骨与关节图像与影像 bone and joint imaging • 上一篇    下一篇

光学定位系统立体匹配中伪点的自动去除方法*★

刘素娟，杨荣骞，吴效明   

  1. 华南理工大学生物医学工程系，广东省广州市 510006
  • 收稿日期:2011-10-20 修回日期:2011-11-30 出版日期:2012-04-22 发布日期:2012-04-22
  • 通讯作者: 杨荣骞，博士，讲师，华南理工大学生物医学工程系，广东省广州市 510006 bmeyrq@gmail.com 并列通讯作者：吴效明，教授，博士生导师，华南理工大学生物医学工程系，广东省广州市 510006 bmxmwus@scut.edu.cn
  • 作者简介:刘素娟★，女，1987年生，河南省许昌市人，汉族，华南理工大学在读硕士，主要从事生物医学测量与仪器方面的研究。 scut_bme2011@163.com
  • 基金资助:

    华南理工大学中央高校基本科研业务费专项资金(2009ZM0235)。

Automatic removal for pseudo markers in optical positioning system 

Liu Su-juan, Yang Rong-qian, Wu Xiao-ming   

  1. Department of Biomedical Engineering, South China University of Technology, Guangzhou  510006, Guangdong Province, China
  • Received:2011-10-20 Revised:2011-11-30 Online:2012-04-22 Published:2012-04-22
  • Contact: Corresponding author: Yang Rong-qian, Doctor, Lecturer, Department of Biomedical Engineering, South China University of Technology, Guangzhou 510006, Guangdong Province, China bmeyrq@gmail.com Corresponding author: Wu Xiao-ming, Professor, Doctoral supervisor, Department of Biomedical Engineering, South China University of Technology, Guangzhou 510006, Guangdong Province, China bmxmwus@scut.edu.cn
  • About author:Liu Su-juan★, Studying for master’s degree, Department of Biomedical Engineering, South China University of Technology, Guangzhou 510006, Guangdong Province, China scut_bme2011@163.com
  • Supported by:

    Central University Special Funds for Basic Research Operating Expenses of South China University of Technology, No. 2009ZM0235*

PDF

384

被引次数

2

摘要：

背景：光学定位系统捕捉到的空间标记点的图像存在特征点相似、场景纹理信息少等情况，使得立体匹配存在多义性，即产生匹配伪点。
目的：分析匹配过程，提出一种有效的自动去除立体匹配中伪点的方法。
方法：根据同一空间点发射的光线位于同一极平面的原理，将匹配特征点的搜索范围限制在一特定区域内，从而减小了搜索区域。然后通过伪点空间坐标的突变性剔除匹配中产生的伪点，从而得到正确的匹配标记点。
结果与结论：实验中对装有3个标记点的模拟手术器械工具进行跟踪。对其连续拍摄40组图像，并选取δ=0.002 5作为初始匹配阈值进行测试。重建的运动轨迹表明该方法可有效的孤立伪点，同时将所得同一时刻的真实点间的距离与真实距离比较，平均误差为0.284 4 mm，相对误差为0.48%。实验结果验证了算法的可行性和有效性。
 

关键词: 立体匹配, 极平面, 标记点, 双目视觉, 光学定位, 伪点

Abstract:

BACKGROUND: The spatial markers can be captured by optical positioning system to form images, in which the feature points are similar and the texture information is difficult to be obtained. There is an ambiguity in stereo matching, which produce pseudo markers. OBJECTIVE: To analyze the process of stereo matching and propose an effective and automatic method for removing the pseudo markers.
METHODS: Because all rays emitted from the same marker lie in the same epipolar plane, the searching for matching feature points could be determined in specific region to reduce the searching area. Pseudo markers existing in stereo matching were removed according to the abrupt change of spatial coordinates of pseudo markers. So the correct markers were obtained.
RESULTS AND CONCLUSION: A simulation operation tool with three markers was tracked in the experiments. 40 groups of images were obtained and δ=0.002 5 was as the initial matching threshold for testing the algorithm. The reconstruction of the movement showed that this method could effectively isolate the pseudo markers. Compared with the real distances, the error of the computed distances of real markers at the same time was 0.284 4 mm, the relative error was 0.48%, which demonstrated the effectiveness and feasibility of the proposed algorithm.

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