Patent ID: 6301387
Filing Date: 2001-10-09
Classification: G06K

Abstract:
A method for locating a match between a first template of data and a search area of data, the first template including a first plurality of data points, the search area including a second plurality of data points exceeding in number the first plurality of data points, the method comprising the steps of:padding the first template with additional data to enlarge the template into a padded template, wherein a first window area within the padded template is formed by the first template and includes the first plurality of data points;selecting a subset of window areas within the search area by using a step size, the step size being determined by comparing the first template with the padded template; andevaluating a selected subset of window areas for locating a match between the first template of data and the search area of the data;wherein the step of selecting comprises the steps of:(a) correlating the first template to window areas within the padded template along a first axis about the first window area to derive a first step size; and(b) correlating the first template to window areas within the padded template along a second axis about the first window area to derive a second step size;wherein the step of correlating the first template to window areas within the padded template along the first axis about the first window area comprises the steps of:(i) correlating the first template to window areas within the padded template along the first axis about the first window area to achieve a correlation coefficient for each said window area;(ii) determining a first distance along the first axis between the first window area and a window area along the first axis in a first direction for which a correlation coefficient conforms to a cut value criteria;(iii) determining a second distance along the first axis between the first window area and a window area along the first axis in a second direction opposite the first direction for which a correlation coefficient conforms to the cut value criteria; and(iv) deriving a first step size from the first distance and the second distance.