High precision 4×4 DST7 and DCT8 transform matrices
US12363346B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 2022 |
| Grant date | Jul 15, 2025 |
| Priority date | — |
| Expiry date | Jun 29, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/70
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for reconstructing a block of a picture comprising: applying an inverse transform to a block of transform coefficients using a first matrix of integer coefficients representative of the inverse transform, wherein the first matrix of integer coefficients is the inverse of a second matrix of integer coefficients representative of a transform inverted to obtain the inverse transform, the second matrix of integer coefficients being derived from a third matrix of integer coefficients, the absolute values of the integer coefficients of the third matrix taking their values in a set of four different values, the derivation comprising a modification of one value of the set to ensure that a sum of two values of the set equals a third value of the set.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.