Two layer video signal coding
US5349383A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1993 |
| Grant date | Sep 20, 1994 |
| Priority date | — |
| Expiry date | Apr 30, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of coding a video signal for transmission includes the steps of coding data representing the video signal by a base layer coding operation which includes base layer quantizer having a base layer quantization step size to provide coded video data for transmission; deriving inverse-coded video data by carrying out an inverse base layer coding operation on the coded video data; deriving difference data from the data representing the video signal and the inverse coded video data; and coding the difference data by an enhancement layer coding operation only when the energy of the difference data exceeds a variable threshold, the threshold being inversely proportional to the base layer quantization step size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.