Method and apparatus for video signal bandwidth reduction with high quality compatible signal
US5457497A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 8, 1993 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Mar 8, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/39
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A temporally-subsampled video signal from a bandwidth reduction encoder is processed prior to transmission in order to reduce the judder effects that would otherwise be present when the encoded signal was viewed directly on a receiver not equipped with a bandwidth reduction decoder. A fraction 1/N of the samples are transmitted in the first field of each group of N fields, where N is the temporal subsampling ratio. Each of the other N-1 fields is formed by projecting the first field along the estimated motion trajectory to the appropriate time instant and adding to this projection the difference between another group of the N/1 samples and an estimate of these samples derived from those transmitted in the first field. At the decoder, the projected fields and the estimate of the samples can be derived from the samples in the first transmitted field of the group for each subsequent field. Using this information, the values of the other sets of samples can be derived from the subsequent transmitted fields, yielding the original temporally-subsampled signal. This signal is then decoded by the bandwidth reduction decoder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.