DSPI for Surface Displacement Measurement
Digital Speckle Pattern Interferometry (DSPI) for surface displacement measurement is studied in this paper, we design an optical system based on principle of DSPI, and the system is composed of Twyman-Green interference system and used in rough surface measurement. The basic principle is the reference beam is introduced to the speckle field, so the reference beam is interference with the speckle field, at the same time, receive the interference fringes by CCD and input the fringes to the computer in order to carry on digital image processing. According to the characteristic of the speckle pattern and its high noise, we present subtraction method to process image, image of speckle interference field before and after deformation is stored in the CCD, subtract them and take the absolute value, the correlative fringe pattern include objects displacement information is obtained. Because of the noise existed in the speckle interference pattern and the granularity is strong, so the S/N of the speckle interference pattern is small and the contrast is low. This paper applies filter program wrote by Matlab, eliminates the effects of digital speckle interference pattern effectively which caused by pellet noise, improves the contrast of fringe and increases the definition of image, based on the study of the de-noising ability of all kinds de-noising algorithm in spatial domain and frequency-domain.
digital speckle interference correlative fringes speckle interference pattern displacement digital image processing
Haojun PANG Zhenjie FAN Wensheng WANG
Laboratory of Contemporary Optical Measure Technology,Changchun University of Science and Technology, Changchun, Jilin, China, 130022
国际会议
第八届国际测试技术研讨会(8th International Symposium on Test and Measurement)
重庆
英文
291-294
2009-08-01（万方平台首次上网日期，不代表论文的发表时间）