Method and apparatus for decoding bar code symbols using subpixel interpolation
US5550365A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1994 |
| Grant date | Aug 27, 1996 |
| Priority date | — |
| Expiry date | Mar 22, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/1469
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for decoding a bar code symbol receives a signal representative of the symbol and searches the signal in one dimension to locate two adjacent critical points corresponding to an element of the symbol. The system also computes a value representative of the signal energy between the two critical points and determines the width of the element in accordance with the value. A bar code symbol decoding system receives a signal representative of a bar code symbol having a plurality of characters, one of which is a checksum character. The system determines a first choice for each of the characters and a second choice for at least one of the characters from the signal. The system performs checksum analysis in accordance with the first choice for each of the characters. If that checksum analysis is not satisfied, then the system performs checksum analysis using the second choice.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.