Image encoding and decoding method and apparatus
US4868764A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1987 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Apr 6, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/004
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Pixel information representing an image for display is encoded using data compression into display data which can be stored on a compact disc. The data compression consists in obtaining the pixel information as a first matrix of high resolution pixel values, subtracting from this first matrix a second matrix composed of lower resolution pixel values, produced by low pass filtering the first matrix, to produce a third matrix of difference values, decimation filtering the second matrix to produce a fourth matrix of less density lower resolution pixel values and encoding the third and fourth matrices. The complementary decoding to obtain the original data consists in restituting the second matrix by interpolation filtering the coded fourth matrix, and combining the restituted second matrix with decoded third matrix. The coding of the third matrix takes into account rate of change pixel value information obtained by delta coding the fourth matrix and the decoding of the third matrix takes into account equivalent rate of change pixel information available at the interpolation filtering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.