Method for encoding and decoding image block, encoder and decoder
US9948956B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 2015 |
| Grant date | Apr 17, 2018 |
| Priority date | — |
| Expiry date | Nov 17, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/98
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for encoding and decoding an image block, an encoder, and a decoder are provided. The method for encoding an image block comprises: determining a local dynamic range of the block; adaptively precision-extending pixel values of the block based on the local dynamic range of the block; and encoding the block with an adaptively extended precision. The method for decoding an image block comprises: determining a minimum pixel value of the block and an indicating value for indicating a precision extension factor according to precision extension information; decoding the block according to the indicating value; and de-extending precision of the decoded block based on the minimum pixel value of the block and the precision extension factor. The precision of the intermediate calculations may be improved without increasing an original intermediate bit depth used in intermediate calculations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.