Method and apparatus for generating quantization matrices in video encoding and decoding
US11172226B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2018 |
| Grant date | Nov 9, 2021 |
| Priority date | — |
| Expiry date | Dec 21, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/645
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
When a 2D separable transform is used in video encoding and decoding, two 1D quantization matrices (QMs) are designed based on the horizontal transform and vertical transform of the 2D separable transform. The choice of a 1D QM can be based on whether the horizontal or vertical transform is transform skip, or based on the type of horizontal or vertical transform. Then a 2D QM can be obtained from the product of those two 1D QMs. In a different implementation, an initial 2D QM may be modified based on the 1D QMs. The 2D QMs can be pre-computed and stored in a look-up table for the encoder and decoder. During quantization and de-quantization, the 2D QM to be used for a block can be computed on the fly or retrieved from the look-up table based on the 2D separable transform that is used for the block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.