Apparatus and methods for re-compression having a monotonic relationship between extent of compression and quality of compressed image
US8805109B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2011 |
| Grant date | Aug 12, 2014 |
| Priority date | — |
| Expiry date | Jun 13, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A computerized method for independent disjoint block-level recompression of a first image generated by independent coding of disjoint blocks in a precursor image, the first image having at least one first quantization matrix associated therewith, the method comprising performing at least one independent disjoint block-level compression operation, using a processor on the first image, thereby to generate a re-compressed second image including generating a new quantization matrix and using the new quantization matrix for the independent disjoint block-level compression, including computing a rounding error created by the quantization process utilizing the new quantization matrix and, if needed, adjusting at least one value of the new quantization matrix to reduce a rounding error created by the quantization process utilizing the new quantization matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.