Methods and apparatus for gray image based text identification
US6301386A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1998 |
| Grant date | Oct 9, 2001 |
| Priority date | — |
| Expiry date | Dec 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for gray image based text identification. A gray image of a document is preferably subsampled to reduce the amount of information to be processed, while retaining sufficient information for successful processing. The subsampled image is subjected to preprocessing to remove horizontal and vertical lines. The image is then subjected to a morphological open operation. The image is then segmented to separate foreground and background information to produce a foreground image. Region filtering and merging are performed on the foreground image. Region features are then extracted and region identification performed. Homogenous regions are grouped and noise elimination performed, resulting in a number of small regions of known types. Optical character recognition can then be performed on each of the regions. The use of the information provided by variations in pixel lightness and darkness enables text identification to proceed quickly and efficiently.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.