Comparative Study on the Sub-pixel Searching Methods of Digital Speckle Correlation Method

摘要

DSCM (Digital speckle correlation method) has some unique advantages compared with other technologies as a non-contact measurement method of object displacement or the field of surface deformation. In DSCM, Sub-pixel searching technology is not only the main method to improve measuring accuracy, but also the largest calculation consumption step in data processing. This paper has given studies on the common Sub-pixel searching technologies such as quadric surface fitting, Gaussian surface fitting, bilinear interpolation and the gradient method. The system has been built and the analysis on the accuracy and efficiency of these technologies has been given based on the result of the measurement.