作者：陈冬雪¹, 刘桂雄¹, 彭艳华¹, 钟浩¹, 曾启林²

作者单位：1. 华南理工大学机械与汽车工程学院, 广东 广州 510640;
2. 广州华工百川科技有限公司, 广东 广州 510640

关键词：轮胎;剪切散斑干涉;相位图;多方向;频域滤波

摘要：

为解决激光数字剪切散斑干涉技术应用于轮胎缺陷检测中轮胎缺陷相位条纹图噪声对包裹相位图解包和轮胎缺陷尺寸测量产生严重影响问题,通过对散斑干涉相位图的形成与条纹特征分析,研究一种根据不同方向的条纹密度来设置不同截止频率的多方向频域低通滤波方法。该方法只需进行一次滤波就能有效滤除噪声,还能更好地保留图像的边缘信息。实验结果表明:在两组滤波实验中,与中值滤波方法相比,多方向频域低通滤波的边缘保持指数分别是其4.257倍、2.869倍;与正余弦滤波方法相比,多方向频域低通滤波方法的残差点数分别是正余弦滤波方法的16.456%、36.555%,体现出较好的滤波特性。

Multidirectional frequency domain filtering for phase pattern of tire detects by laser speckle interferometer

CHEN Dongxue¹, LIU Guixiong¹, PENG Yanhua¹, ZHONG Hao¹, ZENG Qilin²

1. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China;
2. Guangzhou SCUT Bestry Technology Co., Ltd., Guangzhou 510640, China

Abstract: A multidirectional low-pass frequency domain filter has been introduced in this paper to prevent the noise in phase fringe patterns of laser digital speckle-shearing interferometer from affecting the result and accuracy of phase unwrapping and the measurement of tire defect size based on the analysis of the formation and fringe characteristics of phase patterns. The cut-off frequency of this method is decided by the different density of phase fringe patterns in different directions. The method can screen most noises and can better preserve the image edge information at one time. The edge preserve index(EPI) of this filter is 4.257 times and 2.869 times higher than median filters and the number of residua is 16.456% times and 36.555% times higher than the sin/cos method in two groups of smoothing experiments. The result shows that this method has better filter property.

Keywords: tire;shear speckle interferometer;phase patterns;multi-direction;frequency domain filter

2015, 41(11): 88-92  收稿日期: 2015-04-10;收到修改稿日期: 2015-05-23

基金项目: 粤港共性技术招标项目(2013B010134008)

作者简介: 陈冬雪(1991-),男,江西吉安市人,硕士研究生,专业方向为先进传感器技术与应用。

参考文献

[1] 王暐,王春平,付强. 基于梯度的自适应椒盐噪声滤波算法[J]. 中国测试,2013,39(6):28-31.
[2] Pilevar A H, Saien S, Mina K, et al. A new filter to remove salt and pepper noise in color images[J]. Signal Image and Video Processing,2015,9(4):779-786.
[3] Gao J Y, Wang K F. Study and design of exponential and Butterworth low-pass filters used for digital speckle interference fringe filtering[J]. Optik,2013,124(2013):6713-6717.
[4] Qian K M. Two-dimensional windowed Fourier transform for fringe pattern analysis:Principles, applications and implementation[J]. Optics and Lasers in Engineering,2007(45):304-317.
[5] LI C C, Chen T. Localized fourier transform filter for noise removal in electronic speckle pattern interferometry wrapped phase patterns[J]. Applied Optics,2011,50(24):4903-4911.
[6] 王永红,李骏睿. 散斑干涉相位条纹图的频域滤波处理[J].中国光学,2014,7(3):389-295.
[7] 蔡长青. 散斑干涉计量关键问题研究及其应用[D]. 广东:华南理工大学,2013.
[8] Yao S N, Collins T. Hybrid method for designing digital butterworth filters[J]. Computers & Electrical Engineering,
2014,38(4):811-818.
[9] 李骏睿. 基于空间载波相移的激光散斑测量系统[D]. 安徽:合肥工业大学,2014.
[10] 吴文娟. 矿区SAR干涉图滤波方法研究-以南屯煤矿为例[D]. 江苏:中国矿业大学,2014.
[11] 冯长江,毛博,薛冰. 基于运动估计结合小波分析和运动补偿的视频去噪方法[J]. 中国测试,2013,39(5):1-5.
[12] 龚胡,石强. 基于平均梯度的边缘保持指数的图像质量评价[C]//Proceedings of the 2011 International Conference on Information, Services and Management Engineering(ISME 22011)(Volume3),2011.