Omnidirectional bar code reader with method and apparatus for detecting and scanning a bar code symbol
US5155343A · kind A · utility
Inventors
Key dates
| Filing date | Mar 28, 1990 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Mar 28, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/1491
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A bar code reader includes an optical system for storing a two dimensional image in memory, which stored two dimensional image contains a bar code symbol. A method and apparatus is disclosed for detecting the location of said bar code image by computing the accumulated sum of the products of the derivatives of respective first and second scan lines as a location score for the image under consideration. The higher the location score, the higher the probability that the area under consideration contains a bar code image. Also, a method and apparatus is disclosed for determining the fine orientation of a located bar code image by the cross-correlation of interpolated scan line data. The bar code image is filtered by shifting interpolated scan line data in accordance with the detected peak of the cross-correlation and combining the shifted scan line data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.