Method and apparatus for rapid and precision detection of omnidirectional postnet barcode location
US6708884B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2002 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Jun 25, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/14
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for rapid and precise detecting of an omnidirectional postnet bar code on an object by digital signal processing is provided. In order to rapidly and accurately detect omnidirectional postnet bar codes, a two-dimensional digital image containing the postnet bar code is acquired, filtered and dilated to form a block dominated by a plurality of black-colored pixels. Then a down sampled image is provided and match filtered with a two-dimensional matched filtering output to indicate a best-matched filter, thus determining a postnet bar code location and orientation by associating matched filters with an orientation angle of the omnidirectional postnet bar code. The method further comprises the steps of identifying a gravity center for each short bar code and connecting the gravity centers to form a straight line by using a Hough transform and comparing the straight line with the postnet bar code location to generate a verification result and then detecting a position and an orientation of said postnet bar code location by matching said postnet bar code location with said verification result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.