摘要
针对光栅投影法三维测量中的相位展开问题,提出一种用四步相移法求取折叠相位的解决方案。在相移图中,提取带有90°相移的4个单周期正弦条纹,对4个单周期正弦条纹进行编码组合,生成错位条纹。测量中,摄像机获取的错位条纹图像和相移图像按灰度值相减,得到4幅条纹差图,提取各差图中灰度值为零的条纹,依此确定错位条纹图像中各个单周期正弦条纹的初始相位特征,然后结合错位条纹的编码序列,获取各个单周期条纹的阶次。整个阶次获取过程仅需要一幅辅助条纹图像,且算法本身具有较高的鲁棒性。实验结果表明,本文算法可以对表面高度变化较为复杂的物体三维信息进行有效提取,具有良好的实时性和准确性。
A novel algorithm is proposed to solve the phase unwrapping problem in three-dimensional（3D） shape measurement.Firstly,the phase was computed by the four-step phase shift method.In each phase-shift fringe,a sinusoidal stripe with the length of a period could be acquired at the same position,so it could get four stripes with 90° phase-shift.Then the interlaced fringe was composed by coding the four stripes.In the measurement,by subtracting the interlaced fringe from the four phase-shift stripes acquired from the camera,four fringe-difference images which have 0-value stripes could be got.Thus the position and the characteristic of each stripe in the interlaced fringe could be distinguished,and then combining with the composing of the coding interlaced fringe,the order of the fringe could be obtained.The whole process needs only one assistant image.The results of experiment show that the algorithm works well in the measurement of object with complex surface or step height and can get the information rapidly and exactly.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2011年第2期249-255,共7页
Journal of Optoelectronics·Laser
基金
国家自然科学基金资助项目(60775025)
新世纪优秀人才支持计划资助项目(NCET-07-0178)
江苏省自然科学基金资助项目(BK2007116)
关键词
光学测量
解相位
错位条纹
光栅投影
optical measurement
phase unwrapping
interlaced fringe
grating projection
