Laboratory and flight tests of IPCT method

Abstract

Image Pattern Correlation Technique (IPCT) is high precision optical measurement of surface shape and surface deformation which is based on computer processing of images with the help of correlation algorithms. It also can be applied for controlling surface movement and rotation. For deformation analysis areas on the test object which are suspected to suffer deformation are covered with special image – pattern (background screen). Pattern can be a random dot image or something else. After deformation surface of test object changing and images of pattern which is getting with the help of camera before and after deformation differ. So after processing these images information about test object deformation can be obtained. Cross correlation processing consist in dividing two images into small parts and calculating function of correlations of corresponding parts. Maximum of correlating function shows us direction and amount of image part displacement. Special mathematical model allow to make qualitative or quantitative vector field of deformation (displacement) using information of displacements.