The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 27, 1999
Filed:
Jan. 31, 1996
Allan Chiwan Cheung, Chicago, IL (US);
Scott Michael Heydinger, Lexington, KY (US);
Steven Frank Weed, Lexington, KY (US);
Lexmark International, Inc., Lexington, KY (US);
Abstract
Digital halftoning is used to reduce the number of pixel levels used to represent a multiple dot plane image to a smaller number of pixel levels for display on an output device such as an ink-jet printer. Two algorithms commonly used to halftone the dots of a given dot plane are error diffusion and ordered dither. Error diffusion produces patterns of dots that are pleasing to the human visual system but is computationally complex. Ordered dither operates quickly but produces patterns of dots that are visually objectionable. A method is taught in the present invention that employs error diffusion to halftone dot planes that contain relatively dark dots that are visually apparent, and employs ordered dither to halftone dot planes that contain relatively light dots that are not noticeable. The resulting output is pleasing to the human visual system and computed quickly.