Document matching and annotation lifting
US6968085B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 2001 |
| Grant date | Nov 22, 2005 |
| Priority date | — |
| Expiry date | May 6, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for matching an original document image with a copy image is disclosed. The original document image is defined as an ensemble of blocks, each of the blocks having neighboring blocks. A mask is formed for each of the blocks by dilating foreground pixels included in the block. A best match is searched in the copy image, for each of the blocks, using a search window, by correlating pixels in the mask with pixels in a corresponding portion in the copy image. Each of the best matches has a matching score. Each of the blocks is indicated as “unmatched” when the corresponding matching score is less than a matching threshold. A displacement vector is computed for each of the matched blocks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.