Video image filtering
US5369447A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 7, 1992 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Oct 7, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video image filtering system is described which utilises multi-tap filters (70). In order to reduce the effects of edge distortion due to the finite size of the input image, extension data is added both the beginning and end of each raster line of data fed to the multi-tap filter (70). The function of the extension data is to pre-load the multi-tap filter (70). With a system constrained to operate at a constant sample rate, there is insufficient inter-raster line separation to accommodate the extension data needed for a long multi-tap filter (70). The system transforms the input video signal format (24) to a reformatted video signal format (28, 30) in which either the horizontal blanking or vertical blanking period has been maximised at the expense of the corresponding other blanking period. Having been reformatted, the raster lines are fed to a line store 60 from where sample values are read and output to the multi-tap filter 70 in the appropriate order to prefix or suffix the extension data to the original active video data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.