Apparatus and method for calibration of projected target point within an image
US6997387B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2002 |
| Grant date | Feb 14, 2006 |
| Priority date | — |
| Expiry date | May 13, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/1255
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a novel optical reader device and method for calibrating the device. The device executes a calibration module that locates the actual coordinates for a targeting symbol in a captured image. The coordinates are stored as calibration coordinates in the memory. During normal operation of the reader device, the stored calibration coordinates are used to locate a target, such as a bar code. In order to locate the targeting symbol, the calibration module may overlay a template on clusters that may be the targeting symbol. A reasonable accurate comparison identifies the cluster as the targeting symbol. Alternatively, the calibration module may approach a cluster from four frames of the image and identify the cluster's tangents and perimeter. Geometrical calculations are used to identify the center of an identified targeting symbol.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.