Simulation of the image shear measurement with subpixel accuracy

Abstract

. The purpose of this research was the evaluation of measurement accuracy for image motion in CCD matrix plane while creating a testing technology for thermal stability of technical products made of the carbon fiber reinforced plastic. Methodology. Mathematical modeling methods and digital image analysis (using MATLAB) have been used during the research. The magnitude of the image shear is suggested to be determined from the shift of the reference mark geometric center. Mathematic model of the laser spot digital image is used as a reference mark. Findings . Modeling technique for sub-pixel shear of a laser spot has been developed. Accuracy estimation of the image shear determination was made during the experiment. Impact of the change in the number of luminance quantization levels by preliminary processing of the original image was investigated for evaluation measurement sensitivity. The correspondence between the informative parameters of the technical image and the parameters characterizing the sub-pixel image shift has been confirmed. Originality of this study is the admission of the problem in controlling the thermostability of products made of carbon reinforced polymer composite materials by measuring the shear of digital images and investigating the effect of image recording conditions on the sensitivity and accuracy of measurements. Modeling techniques confirmed possibility of determining an image shear with sub-pixel accuracy using CCD matrix. Practical value . The solution of this problem will allow creating new measurement technologies for the input control of parts made of carbon reinforced plastic materials with a low coefficient of thermal expansion. Thus, it becomes possible as an output control of large-sized products thermostability, as well as monitoring the dimensional stability of products under operating conditions, including varying humidity conditions. The practical area of this results would be technical vision systems, aerospace technical facilities monitoring, particularly telescopes, truss structures and space-based antennas made of materials with a low coefficient of thermal expansion, as well as the design of digital autocollimators.