Method and apparatus for increasing the vertical definition of a transmitted television signal
US4866519A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1987 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Sep 2, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/28
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of enabling an increase in the vertical definition of a transmitted television signal while preserving its bandwidth including the steps of decimating alternate lines of the television signal and reinterpolating untransmitted alternate lines upon reception. The decimation is accomplished by diagonally filtering the television signal in two dimensions to form a figure of five sample structure. Every other line is then added to the line adjacent to it so that half the lines are available for transmission, each line comprising folded-in high frequency information about missing line samples. Prior to transmission, bnadwidth is converted by filtering the signal to be transmitted at a skew-symmetric low pass filter. Apparatus for encoding and decoding the television signal each includes a two dimensional diagonal filter and line switching and control circuitry. The storage of a full field of a sample data is not required for processing in accordance with the present method. Consequently the present apparatus comprises only line store means associated with the line switching and control circuitry of encoding apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.