Method and apparatus for generating halftone output
US5930396A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 1997 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Apr 22, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4051
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of generating halftone output on an output device. The method includes retrieving at least one table which associates gray levels with halftone results for a region of an output frame including more than one pixel, determining a reference gray level for a tile of an output frame including more than one pixel, using the at least one table to determine a halftone result for the reference gray level, storing the halftone result for the reference gray level to the tile of the output frame, and delivering the output frame to the output device. The table may be generated from a set of thresholds, which may be a threshold array. A first table may associates gray levels with codes and a second table may associates codes with halftone results, and the method may include converting the reference gray level to a reference code with the first table and converting the reference code to the halftone result for the reference gray level with the second table. Converting the reference gray level to a code may occur during a front-end interpretation and converting the reference code to the halftone result may occur during a back-end rendering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.