Method and apparatus for coding digital image data
US5319469A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 6, 1992 |
| Grant date | Jun 7, 1994 |
| Priority date | — |
| Expiry date | Feb 6, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/93
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In the coding of image data corresponding to a raster of pixel values, a generalized run length coding is used in respect of the difference between the pixel values in the raster line to be coded and the pixel values in the same position in the preceding raster line, such that with respect to multi-value pixels (gray values), the generalized run length coding comprises an approximation of the course of the differences as a function of the position in the raster line with a linear function and the code then contains the number of pixels and a characterization of the approximating function, and with respect to binary pixels (on/off), the length is simply a determination of the series of pixel values each equal to the pixel value in the same position in the preceding raster line, wherein in a particularly effective embodiment, this generalized run length coding with respect to the preceding line is combined with generalized run length coding of the pixel values within a line, both methods each being performed in parallel, and the method delivering the most effective code that is the longest series of pixels, compensated for by the length of the code itself, is selected for the actual …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.