The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 05, 2001

Filed:

Dec. 18, 1998
Applicant:
Inventors:

Shijun Sun, Seattle, WA (US);

Yongmin Kim, Seattle, WA (US);

Assignee:

University of Washington, Seattle, WA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06K 9/62 ; G06K 9/64 ;
U.S. Cl.
CPC ...
G06K 9/62 ; G06K 9/64 ;
Abstract

A template is analyzed to determine step sizes for searching within a search area. The template is analyzed by first padding the template with data points to increase its size. Cross-correlation between the padded template and the original template leads to identification of an effective step size along multiple axes. Step sizes for each of a horizontal, vertical and a third axis are derived. Third axis step sizes may correspond to rotation, scaling factor, subsampling factor, linear distance, time or frequency. Windows of the search area, 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.


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