Coding of quantization matrices using parametric models
US11457214B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2019 |
| Grant date | Sep 27, 2022 |
| Priority date | — |
| Expiry date | Aug 8, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/70
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Quantization matrix can be used to adjust quantization of transform coefficients at different frequencies. In one embodiment, a single fixed parametric model, such as a polynomial is used to represent a quantization matrix. Modulation of bit cost and complexity is achieved by specifying only the n first polynomial coefficients, the remaining ones being implicitly set to zero or other default values. One form of the single fixed polynomial is a fully developed polynomial in (x, y), where x, y indicate the coordinates of a given coefficient in a quantization matrix, with terms ordered by increasing exponent. Since higher exponents are the last ones, reducing the number of polynomial coefficients reduces the degree of the polynomial, hence its complexity. The polynomial coefficients can be symmetrical in x and y, and thus reducing the number of polynomial coefficients that need to be signaled in the bitstream.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.