| US 7,450,741 B2 | ||
| Gray scale matcher | ||
| Sam M. Daniel, Tempe, Ariz. (US); Peter Z. Lo, Lake Forest, Calif. (US); and Harshawardhan M. Wabgaonkar, Lake Forest, Calif. (US) | ||
| Assigned to Motorola, Inc., Schaumburg, Ill. (US) | ||
| Filed on Jun. 22, 2004, as Appl. No. 10/873,790. | ||
| Claims priority of provisional application 60/480881, filed on Jun. 23, 2003. | ||
| Prior Publication US 2004/0258284 A1, Dec. 23, 2004 | ||
| Int. Cl. G06K 9/00 (2006.01) | ||
| U.S. Cl. 382—124 [382/115; 382/125] | 24 Claims |
| 1. A method for comparing a first print image having a first set of minutiae to a second print image having a second set of
minutiae, wherein at least a second subset of minutiae from the second set is mated to a first subset of minutiae from the
first set, the method comprising the steps of:
selecting a first pair of minutiae from the first subset and a second pair of corresponding mated minutiae from the second
subset;
generating a first segment by connecting the first pair of minutiae, wherein the first pair of minutiae are endpoints to the
first segment and a second segment by connecting the second pair of minutiae, wherein the second pair of minutiae are endpoints
to the second segment;
extending the first segment or the second segment so that one segment is longer than the other segment;
generating a first cross-section waveform profile based on the first segment and a second cross-section waveform profile based
on the second segment, wherein the extended segment is used to generate a corresponding extended cross-section waveform profile
that is longer that the other cross-section waveform profile by a predetermined number of samples;
computing at least one similarity measure that is indicative of the similarity between the first cross-section waveform profile
and the second cross-section waveform profile by correlating the shorter cross-section waveform profile against the extended
cross-section waveform profile; and
calculating a metric based on the at least one computed similarity measure which indicates similarity between the first print
image and the second print image.
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