Hybrid image reduction method and apparatus with moire suppression
US6181834A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1998 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | Sep 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40075
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for digital image reduction using an improved "extendible" perspective projection technique which allows for flexible control of the averaging cell or window size separately from the reduction ratio to improve moire suppression or sharpness as desired in the resulting reduced-size image. The extendible perspective projection technique can also be implemented together with ordinary perspective projection or together with a combined one-dimensional filter and linear interpolation technique to produce a reduced-size image of a quality comparable to those produced by the prior technique of using a two-dimensional pre-filter prior to interpolation at a much lesser cost due to the reduced number of required scanline buffers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.