A method of and system for rendering a halftone image of a gray scale image by utilizing a pixel-by-pixel comparison of the gray scale image against a blue noise mask is disclosed in which the gray scale image is scanned on a pixel-by-pixel basis and compared on a pixel-by-pixel basis to an array of...http://www.google.de/patents/US5477305?utm_source=gb-gplus-sharePatent US5477305 - Method and apparatus for halftone rendering of a gray scale image using a blue noise mask
