Browse Prior Art Database

THREE-PIXEL CHARACTERIZATION OF HEXAGONAL PIXEL GRIDS

IP.com Disclosure Number: IPCOM000027684D
Original Publication Date: 1998-Oct-31
Included in the Prior Art Database: 2004-Apr-08
Document File: 2 page(s) / 108K

Publishing Venue

Xerox Disclosure Journal

Abstract

US Patent 5,469,267 to Wang discloses a system of mathematically characterizing any kind of halftone pattern. In the scheme of this patent, any image containing halftones is characterized as comprising a large number of square cells. Each of these cells is considered to have, at one comer thereof, a location where a halftone dot is possibly centered. Under this scheme, only seven types of cells could possibly exist, and any kind of halftone pattern, such as created by a digital printer, could be characterized as a combination of any number of these seven types of cells. This characterization scheme, as explained in the patent, enables relatively quick and simple techniques for analyzing halftone patterns obtained in various ways, and can be used to calibrate digital printers.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 55% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

THREE-PIXEL CHARACTERIZATION OF Proposed Classification HEXAGONAL PIXEL GRIDS
U. Steven J. Harrington S. CL 3581298
Int. C1. H04n 01/21

US Patent 5,469,267 to Wang discloses a system of mathematically characterizing any kind of halftone pattern. In the scheme of this patent, any image containing halftones is characterized as comprising a large number of square cells. Each of these cells is considered to have, at one comer thereof, a location where a halftone dot is possibly centered. Under this scheme, only seven types of cells could possibly exist, and any kind of halftone pattern, such as created by a digital printer, could be characterized as a combination of any number of these seven types of cells. This characterization scheme, as explained in the patent, enables relatively quick and simple techniques for analyzing halftone patterns obtained in various ways, and can be used to calibrate digital printers.

Proposed here is a variation on the square-cell concept in the '267 patent. A halftone pattern comprising hexagonally-arranged pixels is divided into a large number of triangular regions, each corner of each triangle being centered on a pixel area, such as shown in the

XEROX DISCLOSURE JOURNAL - Vol. 23, No. 5 SeptembedOctober 1998 229

[This page contains 1 picture or other non-text object]

Page 2 of 2

THREE-PIXEL CHARACTERIZATION OF HEXAGONAL PIXEL GRIDS (CONT'D)

figure. In any halftone area, there would thus be only four possible types of triangular cell, depending on whether there were 0, 1,2, or 3 spots at t...