Hierarchical histogram calculation with application to palette table derivation
US11076151B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2019 |
| Grant date | Jul 27, 2021 |
| Priority date | — |
| Expiry date | Sep 30, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/593
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Systems, apparatuses, and methods for calculating multi-pass histograms for palette table derivation include an encoder that calculates a first histogram for a first portion of most significant bits (MSBs) of pixel component values of a block of an image or video frame. Then, the encoder selects a given number of the highest pixel count bins from the first histogram. The encoder then increases the granularity of these selected highest pixel count bins by evaluating one or more additional bits from the pixel component values. A second histogram is calculated for the concatenation of the original first portion MSBs from the highest pixel count bins and the one or more additional bits, and the highest pixel count bins are selected from the second histogram. A palette table is derived based on these highest pixel count bins selected from the second histogram, and the block is encoded using the palette table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.