Image boundary detection for a scanned image
US5995661A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 1997 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Oct 8, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30176
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A bounding box is generated for a scanned image. A vertical edge of the scanned image is detected. A horizontal edge of the scanned image is also detected. The vertical edge is used as a rightmost edge of the bounding box. The horizontal edge is used as a bottom edge of the bounding box. The vertical edge is detected by, for each scan row, detecting when a first pixel in a substep of pixels of the scan row has a grey value which differs from a grey value of a pixel immediately to the right of the first pixel by at least a first predetermined constant. When such a first pixel is found, any edge from a previous row which is continued by the first pixel is detected. A longest edge in any row continued by the first pixel a length of the longest edge is stored. Also stored is an indication of a rightmost pixel of any edge continued by the first pixel. When the length of the longest edge continued by the first pixel exceeds a second predetermined constant, an x-coordinate of the rightmost pixel of any edge continued by the first pixel is stored as a current rightmost edge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.