High speed cosine transform
US4829465A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 19, 1986 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Jun 19, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F17/147
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A discrete transform cosine circuit utilizing symmetries of the cosine matrix of coefficients to allow all multiplications to be done by "constant multipliers" comprising combinations of look-up tables and adders. Transform coefficients are developed by dividing each into a sequence of blocks of preselected size, the information in the blocks is sorted to develop a specific order and the reordered blocks are applied seriatim to a first one-dimensional cosine transform circuit employing the constant multipliers. The output of the first cosine transform circuit is applied to a transposing memory and then to a second cosine transform circuit that also employs "constant multipliers".
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.