Method and apparatus for adaptive context modeling in video encoding and decoding
US11310505B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2019 |
| Grant date | Apr 19, 2022 |
| Priority date | — |
| Expiry date | Apr 8, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/463
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A significance-coefficient flag indicates whether a given quantized transform coefficient is equal to zero or not. To encode the significant-coefficient flags, context-based entropy coding can be used. To adapt to the characteristics of a video sequence, the context model is selected based on the statistics of the transform coefficients. In one embodiment, the non-zero probabilities of transform coefficients are compared to different thresholds to divide a transform block into several context regions, where all coefficients in a context region use the same set of context models. In another embodiment, the transform block is first divided into several context regions based on the positions of the transform coefficients, and the non-zero probabilities of transform coefficients are compared with a threshold to divide each context region into two sub-regions, where all coefficients in a sub-region share the same set of context models.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.