Research On Image Processing Technology Of Digital Speckle Pattern Interferometry Based Deformation Measurement

Digital speckle interference deformation measurement,as a full-field non-contact optical measurement technology,is widely used to measure physical quantities such as object deformation,displacement,and vibration.The speckle interference image processing,as a key part of digital speckle interference measurement,has an important influence on the deformation measurement accuracy and measurement range.Therefore,research on speckle interference image processing technology is very important.This paper introduced the principle of digital speckle interference measurement technology and the processing method of speckle interference image processing.The speckle interference image processing technology was verified and analyzed.The influence of the phase filtering algorithm on the accuracy of deformation measurement and the phase unwrapping algorithm on the range of deformation measurement were analyzed.On this basis,methods for improving the accuracy of deformation measurement and expanding the measurement range of deformation were proposed.Firstly,a method for evaluating the quality of a phase fringe pattern without a reference image was proposed,which can be used to automatically adjust the phase filtering parameters to improve the efficiency and accuracy of the processing algorithm.Aiming at the constant deviation of phase after unwrapping,a method of unwrapping path revising was proposed to eliminate the deviation.Then,a segmented deformation measurement method was proposed to solve the situation that the deformation measurement range is limited due to too dense phase stripes in the deformation measurement.This method improved the deformation measurement range and the accuracy of the deformation measurement.In addition,aiming at a large amount of computation and timeconsuming in speckle interference image processing,the parallel acceleration of speckle image processing algorithm was designed and realized,and the speed of the algorithm was increased to 9?10 times that of CPU-based processing algorithm.Finally,based on the.net Framework,the software of speckle interferometric deformation topography measurement system was designed and developed.The software realizes the functions of image data acquisition,deformation loading control,phase extraction,phase noise reduction,phase unwrapping,image display and data storage,which has very maintainability and expansibility.