Method and appratus for automatically locating predefined exposure areas in a scanned image
US5198907A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1991 |
| Grant date | Mar 30, 1993 |
| Priority date | — |
| Expiry date | Aug 23, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4078
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Exposure areas in a calibration original are automatically found by reference to a registration mark having a predetermined dimensional orientation relative to the exposure areas. A scanner produces image signals representative of both the exposure areas and the registration mark. A pattern recognition module employs edge detection to distinguish image signals corresponding to the registration mark. Two-dimensional Cartesian coordinates are then extracted from the registration mark and used to further distinguish image signals corresponding to the exposure areas, thereby locating exposure areas although the original may not be properly aligned in the scanner. A preferred registration mark is a pair of orthogonal, intersecting guide bars. By further defining the nominal length of the guide bars, the size of the mark can be established and the exposure areas can be located despite dimensional changes due to magnification error in the scanner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.