Digital halftoning combining dot size modulation screen with dot frequency modulation screen within a single image
US6445465B1 · kind B1 · utility
17Cited by
4References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 29, 1999 |
| Grant date | Sep 3, 2002 |
| Priority date | — |
| Expiry date | Mar 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/405
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of producing a halftone screen having a plurality of halftone dots arrayed along a desired screen frequency. The method comprises: a) using variable size halftone dots arrayed along the screen frequency to reproduce shades of gray equal to and above a predetermined shade of gray, the predetermined shade of gray having a first halftone dot size; and b) reproducing shades of gray below the predetermined shade of gray using the first halftone dot size arrayed along the screen frequency by deleting a number of halftone dots per unit area to obtain gray shades below the predetermined shade of gray.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.