| 摘要 |
<p>A template 38 is analyzed to determine step sizes for searching within a search area 40. The template is analyzed by first padding the template with data points to increase its size. Cross-correlation between the padded template 52 and the original template 38 leads to identification of an effective step size along multiple axes. Step sizes for each of a horizontal, vertical and, optionally, a third axis are derived. Third axis step sizes may correspond to rotation, scaling factor, subsampling factor, linear distance, time or frequency. Windows 42 of the search area 40, selected based on the step sizes, then are tested in a fast search by correlating the template to selected windows to derive correlation coefficients. Any tested window which has a correlation coefficient exceeding a given value is a potential match for the template and is subject to a refined stage of comparison. <IMAGE></p> |
