DISPLACEMENT MEASURING SYSTEM, DETERMINATION METHOD OF CORRELATION FUNCTION PEAK POSITION, STORAGE MEDIUM AND CARRIER WAVE

摘要

PROBLEM TO BE SOLVED: To reduce the system resource quantity necessary for execution of correlation processing and to precisely determine the peak or valley of a correlation function. SOLUTION: When two images are obtained, these images are related only in an offset position corresponding to a sparse set of image correlation function value points. One or more correlation function value points of the sparse set have correlation values showing that these points are present within the peak part of the correlation function. When such correlation function value points are specified, these images are related in an offset position corresponding to a dense set of correlation function value points. The correlation function values of the correlation function value points are analyzed to determine the offset position of the correlation function peak.