Stack filters for 1-to-N bit image processing in electronic printers
US5471320A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1994 |
| Grant date | Nov 28, 1995 |
| Priority date | — |
| Expiry date | May 11, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40075
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is a method and apparatus for the enhancement of 1 bit per pixel image signals to produce a multiple-bit per pixel form. A binary input image is passed through a plurality of filters to generate level slices. The filters are stack filters implemented as look-up table or template-based filters, morphological filters, or any similar binary-to-binary filters that could be used to generate level slices. Each of the N-1 filters is used to produce the slices, where N is the number of possible gray-scale levels desired in the output image. Once the slices are generated, the resulting binary image data therein is recombined, by adding or stacking, to produce the desired multiple-bit per pixel output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.