Error diffusion with partial dots method and system
US6778299B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2001 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Apr 5, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40087
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and system for halftoning images that uses error diffusion with partial dots is provided. First, an input picture element (input pixel) that has a picture level (e.g., gray level) is received. Next, a reproducible gray level is generated based on the gray level of an input pixel. Then, a corrected gray level is generated based on the gray level of an input pixel and an error amount (e.g., error propagated or diffused from adjacent areas or pixels). A determination is made whether the corrected gray level is in a predetermined relationship with a threshold. When the corrected gray level is in a predetermined relationship with the threshold, the reproducible gray level (i.e., partial dot size) is provided as output. When the corrected gray level is not in a predetermined relationship with the threshold, a zero value is provided as output. It is noted that the output gray level and the corrected gray level are provided to an error distribution module for calculating an error and for propagating or diffusing the error to future adjacent areas or pixels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.