Block-by-block data compression with quantization control
US6351226B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 2000 |
| Grant date | Feb 26, 2002 |
| Priority date | — |
| Expiry date | Jul 28, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Data are compressed on a block-by-block basis. A frequency-transformer frequency-transforms input data to generate corresponding groups of coefficient values representing different frequency components. A quantiser operates on the groups of coefficient values to map each of a contiguous plurality of ranges of coefficient values onto respective quantised data values, the extent of each range being controlled by a quantisation factor and the first non-zero range boundary being defined by a range boundary parameter. A detector operates to: (a) trial-encode at least some of the data blocks using a range of at least one quantisation factor and at least a subset of the range of boundary parameter regimes available for use by the quantiser, in order to assess the quantity of compressed data produced with each quantisation factor/boundary parameter regime; (b) trial-decode the trial-encoded blocks using a corresponding quantisation factor but a single predetermined boundary parameter; (c) compare the trial-decoded blocks with the data blocks before trial encoding, in order to assess data errors introduced by the trial-encoding and decoding; and (d) detect whether the relationship between q…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.