Determination of image skew angle from data including data in compressed form
US5245676A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1989 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | Dec 21, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Skew angle of an image is determined based on determination of location of fiducial points on the image. Fiducial points may be located through a comparison of the scanning of a first line with scanning of a subsequent line. These fiducial points may be defined in terms of pixel color transitions located on a first scan line without a corresponding transition on the succeeding scan line. Skew angle may be determined from image data in uncompressed form or in compressed form. Where skew angle is determined from image data in compressed form, the 2-dimensional CCITT facsimile recommendations may be used. In such cases, the locations of the fiducial points may be taken as the locations of the pass codes of the compressed image data. Specifically, pass codes indicating a pass of white pixels are used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.