Acceleration of Area Shift Calculation

Abstract

The goal of the area shift measurement is to find the coordinates (location) of the searched pattern of one two-dimensional sequence in the second two-dimensional sequence. It is supposed that searched pattern is included in the searched sequence in the unknown location. As it was published in [3], it is possible to determine the area shift using either the correlation or difference method. The calculations using the definition equations of the correlation or difference method are very severe. This contribution shows how it is possible to significantly decrease needed amount of the calculation operations when appropriate characteristics of the compared two-dimensional sequences are used. The method, which uses histogram comparison, allows eliminating up to 90 % of the searched patterns from the calculations that use the definition equations. The method that uses the comparison of the mean values of the searched pattern segments reaches even better results. It can eliminate up to 99.9 % of the searched patterns. Both new eliminating methods significantly contribute to acceleration of the area shift calculation.