Virginia A Macdonald

US Patent:

56007337, Feb 4, 1997

Filed:

Nov 1, 1993

Appl. No.:

8/144002

Inventors:

Virginia N. MacDonald - Lansdale PA
Don A. Tran - Perkasie PA

Assignee:

Kulicke and Soffa Investments, Inc - Wilmington DE

International Classification:

G06K 900

US Classification:

382144

Abstract:

A novel method for locating eye point features on patterns or objects whose size varies between the reference object and the find object includes generating a set of reference vectors that define the location of the reference eye point. The set of vectors is modified and separated equidistant from each other. A centroid of the object area is calculated. When a fixed object is to be located, an area of certainty is established which contains a plurality of candidate eye points one of which is the proper find eye point of the object to be located. Sets of find vectors are generated for each candidate eye point which are compared with the set vectors for the reference eye point. Centroids of the find objects having the best comparison are calculated and compared with the centroid of the reference object. The candidate eye point having a best vector correlation match and the best centroid comparison is selected as the eye point of the find object.