IMPROVED HIGHLIGHT AND SHADOW HALFTONE SCREENS
Original Publication Date: 1999-Aug-31
Included in the Prior Art Database: 2004-Apr-09
Xerox Disclosure Journal
Disclosed is an improved halftone design with improved tone range and stability in the highlight and shadow regions. For highlight, the minimum dot size is set to the size that can be reliably printed. This size will be adjusted for each printing process and can be bigger than a full pixel. For shadow, the minimum hole size is determined the same way. A multi-centered screen design, with suitable randomization, and Pulse Width Position Modulation (PWPM), are used to increase the tone range and the number of gray levels.