摘要
利用基于条纹投影技术进行三维测量时,其相位提取精度直接决定着测量精度,而在实际测量中,由于待测物体存在一定反射率,因此相机拍摄到的结构光条纹在一些区域常会曝光过度,导致条纹相位产生高光误差,影响测量结果。本文分析了条纹投影技术中镜面反射光对相位提取精度的影响,提出了一种基于高动态范围图像(High Dynamic Range Image, HDRI)技术的高光误差补偿方法,可在不增加系统复杂度的前提下补偿高光误差,并针对金属工件表面三维形貌进行了测量实验验证,结果表明,在未消除高光误差时,测量高度整体向上平移15 mm,且在高光区域存在额外0~20 mm不等的测量误差,在使用HDRI技术后有效补偿了高光区域的相位误差,提高了金属工件三维测量的准确度。
The measurement accuracy of the fringe projection profilometry technique is affected directly by the accuracy of the extracted phase. In practice, the fringe patterns captured by the camera will be overexposed in any area where the specular reflectivity is high enough. In those areas, the extracted phase of the captured fringe pattern displays what is known as ＂high light error＂. In this paper, the influence of specular reflection light on the phase accuracy is analyzed. Furthermore, a solution based on the High Dynamic Range Image （HDRI） method is proposed to reduce high light error. This method can enhance the phase accuracy without increasing the complexity of the system. In our experiment, measuring a metal workpiece without using high light error reduction, the overall measured height shifts 15 mm due to phase unwrapping error. In high-light areas, additional 0-20 mm measurement errors occur. Conversely, using the proposed error reduction method, the overall measurement accuracy is improved significantly as the high light phase error is compensated for effectively.
作者
吴雨祥
李明阳
杨眉
李绒
岳慧敏
刘永
WU Yuxiang;LI Mlngyang;YANG Mei;LI Rong;YUE Huimin;LIU Yong(School of Optoelectronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 610054,China;School of Physics and Optoelectronic Engineering,Xidian University,Xi＇an 710071,China)
出处
《红外技术》
CSCD
北大核心
2018年第10期972-978,共7页
Infrared Technology
基金
国家自然科学基金(61875035
61805188)
四川省科技计划项目(2018JY0579)
中央高校基本科研业务费(JB180505)
