Platenless book scanning system with a general imaging geometry
US5760925A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | May 30, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04791
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An overhead scanning system records pages from bound documents in an upright and open condition. The scanning system is defined with a general imaging geometry that makes the scanning system readily portable, and provides the scanning system with a variable imaging area. Once an operator defines an imaging area of an image acquisition system, the operator positions a light stripe projector to project across the imaging area. After recording calibration data, a perspective transform is provided by a perspective transform generator. In operation, a first image of the bound document having a light stripe projected there across is recorded by the image acquisition system. A page shape transform generator is then used to derive a page shape transform. Subsequently, a second image of the bound document is recorded without projecting a light stripe thereacross. If the second image is warped because of foreshortening, or magnification due to the pages of the bound document being curved, an image correction system de-warps the second image using the perspective and page shape transforms. The de-warped image is reconstructed by "polling" each location in the second image to determine the val…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.