Orthogonal transform coding system for image data
US5109451A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1991 |
| Grant date | Apr 28, 1992 |
| Priority date | — |
| Expiry date | Jun 28, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An orthogonal transform coding system for images which orthogonally transforms image data to spatial frequencies and divides the domain of the spatial frequencies into low and high frequency domains using a plurality of domain patterns prepared in advance. This system quantizes and encodes the high and low frequency domains of the orthogonally transformed data by different methods. Coding of the data in the low frequency domain is preformed based on bits which are allocated to those data in accordance with their energies. The data in the high frequency domain are decomposed into bit planes and run-length coding is performed for each bit plane, whereby a small number of bits are allocated to those data in the low frequency domain in the coding and an efficient coding of images is accomplished.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.