Back to the main page of LSP/EPFL Peripheral Systems Laboratory (EPFL-DI/LSP)
[Publications] [Patents]

Method and Apparatus for Generating Digital Halftone Images by Using Multi Color Dithering

V. Ostromoukhov, R.D. Hersch

U.S. Patent No. 7,054,038

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.

Download the full paper: Full Text


<basile.schaeli@epfl(add: .ch)>
Last modified: 2007/09/26 21:28:08