Method and apparatus for generating digital halftone images by multi color dithering
US7054038B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 2000 |
| Grant date | May 30, 2006 |
| Priority date | — |
| Expiry date | Jan 4, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention provides a method and apparatus for the reproduction of color images by multi-color dithering. Multi-color dithering is an extension of bi-level dithering for halftoning an input image using as primary colors an arbitrary number of inks. The inks may comprise standard inks or non-standard inks such as non-process color inks, opaque inks, metallic inks, variable color inks and fluorescent inks. Multi-color dithering provides a solution for creating artistic multi-color dithered images, whose screen elements are made of artistic color screen shapes such as micro-letters, symbols and ornaments. When printed at high resolution and at high registration accuracy, multi-color dithering using large dither arrays incorporating artistic dither shapes provides an effective solution for preventing counterfeiting. The use of non-standard inks offers additional protection. Multi-color dithering also offers a solution for printers requiring that all inks are printed side by side, without overlaps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.