Abstract
This paper describes the new algorithms for highly accurate displacement field measurement system to measure the infinitesimal deformation of solids. The proposed methods are based on digital image analysis. The first method, namely, “PIV with vernier” employs the pixelshifting method to increase the resolution of the image and thus, improve the accuracy of the measurement. The second method, namely, “relaxed spatio-temporal gradient method” can handle the field with displacement gradient. Combining these two methods, measurement can be performed with wide dynamic range and the deformation of the solids can be measured with the accuracy of 1/30 pixel.
