Image decoding method, encoding method, devices, terminal equipment and computer programs therefor
US11736694B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 2021 |
| Grant date | Aug 22, 2023 |
| Priority date | — |
| Expiry date | Oct 5, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for decoding a digital image from encoded data representative of the image. The image is divided into blocks processed in a defined order. The method includes, for a current block having a predetermined number (Mv) of lines and number (Mh) of columns: decoding coefficients of the current block from coded data; decoding an index representative of an identifier of a transform among a plurality of transforms and identifying the transform, a transform being expressed as a vertical subtransform of size Mv*Mv and a horizontal subtransform of size Mh*Mh; transforming the current block into a decoded block transformed, from the transform obtained, by successive application of the vertical subtransform and then the horizontal subtransform or respectively of the horizontal subtransform and then the vertical subtransform; and reconstructing the image from the transformed decoded block. The transforming includes: a modified use of core sub-transform coefficients, their absolute values being retained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.