Methods and apparatus for area weighted means processing of barcode signals
US6508405B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 2000 |
| Grant date | Jan 21, 2003 |
| Priority date | — |
| Expiry date | Jan 10, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10851
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques for removing noise effects in processing a barcode signal. A photosignal produced by scanning a barcode is used to generate a digital first derivative signal. Positive and negative thresholds are generated based on the digital first derivative signal. Processing windows are defined for each region of the first derivative signal which exceeds a threshold. Each processing window is bounded by a window opening point at which the first derivative signal exceeds a threshold, and by a window closing point, which is the last crossing of the threshold by the first derivative signal before the first derivative signal makes a zero crossing. Each region is processed to locate a geometric center of the region. A logic transition is recognized for the geometric center of each region defined by a processing window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.