一种适合低信噪比投影栅的时空二维相移算法-论文.pdf

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1、电字·激第25卷第7期2014年7月JournalofOptoelectronics·LaserVo1．25No．7July2014一种适合低信噪比投影栅的时空二维相移算法周灿林，刘业鹏，司书春，刘同川1，杨允鑫(山东大学物理学院，山东济南250100)摘要：提出了一种适合低信噪比投影栅的时空二维相移算法。首先设计四步相移正弦光栅条纹图，由DLP投影仪投影到待测物体表面，再由CCD相机采集受物体形貌调制的变形条纹图；然后对其中一幅变形条纹图进行傅里叶变换以确定抽样间隔，再对4幅相移条纹图用相移法求得条纹背景和调制幅度后，对每幅变形条纹图做归一化处理；对每幅

2、相移条纹图在空间域进行下采样抽样和灰度插值，构建相移莫尔条纹图，得到多帧时空域相移条纹图；对多帧时空域相移条纹图按时空二维相移法处理求得莫尔相位，再将莫尔相位与抽样点相位叠加求和得到变形条纹图对应的相位数据；最后，以面膜作为样品进行了实验测量，结果表明，经典四步相移法重构的物体形貌出现明显失真，而本文方法能较好恢复物体的三维形貌。关键词：抽样云纹法；相位测量轮廓术(PMP)；四步相移法；莫尔条纹；相位去包裹}插值中图分类号：()348；043文献标识码：A文章编号：1005—0086(2014)07—1389—06Aspatiotemporalphase-

3、shiftingprofilometryappliedforthelowsignal—noiseratioprojectionZHOUCan-lin，UUYe-peng，SIShu-chun，UUTong—chuan，YANGYun-xing(SchoolofPhysics，ShandongUniversity，Jinan250100，China)Abstract：Aspatiotemporalphase-shiftingprofilometryisproposedinordertosolvetheproblemofphasedemodulationerr

4、orforthelOWsignal-noiseratio(SNR)fringeprojectioninthree-dimensional(3D)shapemeasurement．Firstly，four-stepphase-shiftingsinusoidalpatternsdesignedbycomputerarepro—jectedontothetestedobjectbyadi酉ta卜light_process(DLP)projectorandthedeformedfringepatternsareacquiredbyaCCDcamera．Thesa

5、mplingpitchisdeterminedbytheFouriertransformmethod．Nor—malizedfringepatternsareobtainedaftertheamplitudeandbackgroundintensitiesaredeterminedbythephase-shiftedmethod．Thenmulti-framespatiotemporalphase-shiftingMoirefringesareattainedbytheprocessofdown-samplingwithasamplingpitchandi

6、ntensityinterpolationinspacedomainforeachfour-stepphase-shiftedfringeimage．Thus，thephasedistributionoftheMoirepatternscanbecalculatedusingtwo-dimensionalspatiotemporalphase-shiftingmethod．Thephasedistributionoftheoriginalde—formedgratingcanbeobtainedbyaddingthephaseofthesamplingpo

7、inttothatoftheMoirepattern．Finally，theexperimentforthefacialmaskisperformedbyfringeprojectiontoverifytheeffectivenessoftheproposedmethod．Theresultsshowthatthereconstructed3DshapeshoWSvisibledistortionwiththestandardfour-stepphase-shiftingalgorithmbutremainsfidelitywiththeproposeda

8、lgorithminstead．Keywords：sampling