Processing system with graphics data prescaling
US5953691A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 11, 1996 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Oct 11, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/64307
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for prescaling graphics data for use in a graphics overlay operating mode of a set top box processing system. RGB pixel data for a given pixel are first converted to luminance and chrominance data for that pixel. The luminance and chrominance data are then prescaled by a blending value associated with the given pixel. An interpolation operation is performed on the luminance and chrominance data as well as on the blending value for the given pixel using corresponding luminance and chrominance data and blending values for at least one other pixel in the stream. This interpolation may include operations such as horizontal filtering and may also include chroma filtering to convert the luminance and chrominance data into a 4:2:2 chrominance format compatible with MPEG-2 video. The interpolation operation produces interpolated luminance and chrominance data and an interpolated blending value for the given pixel. A video signal to be combined with the graphics data is then scaled using the interpolated blending value. The scaled video signal is combined with the interpolated luminance and chrominance data for the given pixel to provide a combined video/graphics sign…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.