正余弦变换和双调滤波相结合的剪切散斑干涉图像去噪方法  

A denoising method combining bitonic filtering and sine-cosine transform for shearography fringe pattern

作　　者：吴荣 陆阳 欧阳爱国 WU Rong;LU Yang;OUYANG Ai-guo(School of Measuring and Optical Engineering,Nanchang Hangkong University,Nanchang 330063,China;School of Mechanical and Electrical Engineering,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]南昌航空大学测试与光电工程学院,江西南昌330063 [2]华东交通大学机电与车辆工程学院,江西南昌330013

出　　处：《中国光学（中英文）》2024年第2期435-443,共9页Chinese Optics

基　　金：国家自然科学基金(No.52305576)。

摘　　要：剪切散斑干涉是一种非接触式、全场高精度光学变形测量技术,由于环境等因素导致采集的散斑条纹图像存在大量随机噪声,进而影响测量精度。传统去噪方法在滤除噪声的同时,容易导致条纹边缘信息的丢失甚至破坏。针对该问题,本文提出基于正余弦变换和双调滤波相结合的剪切散斑干涉图像去噪方法。该方法首先对相位条纹图进行正余弦变换获得两幅图像,其次对这两幅图像分别运用双调滤波方法进行去噪,最后将滤波后的两幅图像合并为最终的相位条纹图。实验结果表明:经本文方法滤波后的相位图散斑抑制指数为0.999,平均保持指数为2.995,证明该方法较传统去噪方法能更好地改善相位图质量,且能较大程度地保留相位条纹的细节及边缘信息。Shearography is a non-contact,full-field,and high-precision optical deformation measurement technology.There is a lot of random noise in the acquired speckle fringe pattern caused by environmental factors,which affects the measurement accuracy.The traditional denoising methods easily cause the fringe information to be lost or even damaged while filtering out the noise.To solve this problem,we propose an image denoising method by combining sine and cosine transform and bitonic filtering.In this method,the phase fringe image is firstly obtained by sine and cosine transform.Secondly,the two images are denoised by the bitonic filtering method respectively.Finally,the filtered two images are merged into the final phase fringe image.Experimental results show that for the filtered phase pattern,the speckle suppression index is 0.999 and the average retention index is 2.995,which prove that the proposed method can improve the quality of the phase pattern better than the traditional denoising method,and can preserve the details and edge information of the phase fringes to a large extent.

关 键 词：剪切散斑 干涉 光学测量 去噪 双调滤波 

分 类 号：TH741[机械工程—光学工程]