Research Of Digital Image Processing Technology Of Espi

Electronic speckle pattern interferometry detecting technology has the features of high precision, no destruction measurement, high detection speed and etc. As a new and effect optic measurements technique, it is widely used on deformation measurement and nondestructive measurement, for example, stress and strain, tire detect and etc. But there are lots of granulation noises; the visibility and contrast of pattern image are quite low, it makes really difficult to accurately extract the information of stress or displacement. For the extraction of the effect precision information from the image, it demands the special image processing method for ESPI image, including image enhancement, image restoration and accurate extraction of phase value of image.With the development of computer technology, the digital image processing technique is widely used on Aero-space, industry detection, security, military, agriculture, education, and it plays more and more important role on these fields. For the recent years, there are much more demands from the interdispline fields and some other special applications. So this research proposes a new digital image processing system for ESPI technique is just satisfy these demands.This paper is based on the research of formation principle of ESPI image, and designs and builds a new digital image processing system for ESPI technique; it uses the mathematical method to choose and redesign the method of image processing, and accomplishes software of ESPI image processing. The dissertation mainly includes:1) Using hybrid programming method in Visual Studio environment, with the powerful image processing function of Matlab and the methods and image structure of OpenCV computer vision library, accomplishes the image acquisition, image file storage and the functions of image processing. Completing image processing software for ESPI which can provide various functions, and it is convenient to extent the functions of this program.2) Designing the image acquisition method based on the SDK of image capture card and OpenCV computer vision library, and it can provide the real-time subtraction, image storage function and it can support all popular image file formats.3) Using the partial differential equations image restoration methods for image preprocessing, processing by using the PM mode and improving TV mode, comparing their performances of image restoration and their effects to the post processing.4) Proposing the quick calculate method of phase value of ESPI image, and providing the function in software; accomplish the acquisition method of phase value of ESPI image based on the image thinning and cubic spline interpolation, comparing the precision of different methods.