Apparatus and method for decoding damaged optical codes
US6685095B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 2001 |
| Grant date | Feb 3, 2004 |
| Priority date | — |
| Expiry date | Aug 1, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/1473
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An improved optical code reading system and method that enhances the ability of a reader to locate a symbol within a field of view and enhances the error-correcting properties of the encoding scheme commonly used in 2D bar codes. The reader offsets the effects of damaged finder patterns and missing symbol perimeters and, thereafter, detects high-level symbol information such as the code type, symbol size, and the number of rows and columns in the symbol. The reader then identifies those missing portions of a damaged symbol and marks each missing data bit location with a predetermined indicator. A decoding algorithm then interprets the missing bit indicator as an error of known location (e.g., an “erasure”), thereby nearly doubling the error correcting strength of all bar codes employing the Reed-Solomon error correction scheme.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.