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:
Mar. 12, 2002
Filed:
Jan. 31, 2000
Brian Edward Cooper, Lexington, KY (US);
Shaun Timothy Love, Lexington, KY (US);
Lexmark International, Inc., Lexington, KY (US);
Abstract
A dispersed-dot stochastic dither array is provided for rendering halftone images having excellent visual quality. For color printing, a separate threshold array is generated for each of the color planes, however, the stochastic screens are interlocked so that the threshold arrays are generated while considering the other color threshold arrays. In this manner, a blue noise distribution may be produced by the individual arrays as well as by any combination of the individual arrays. When generating a single threshold array for a color plane, a particular criterion is used to determine where the next threshold value should be located, and the selection of a threshold location in each array considers the criterion for all the threshold arrays being generated. By using the interlocked threshold arrays approach, the overall visual affect will be improved for both individual threshold arrays and for a combination of more than one of the threshold arrays. The present invention also is used to generating a set of interlocked dot profiles which do not use a threshold array for halftoning. In an opposite sense, the interlocked threshold arrays can be generated without using dot profiles during the formative steps of the threshold array. More than one threshold array could be generated in this manner, and these threshold arrays could also be interlocked with respect to one another. Other alternative methodologies include globally optimizing interlocked threshold arrays by simultaneously considering all tone levels for all threshold arrays being generated to avoid locally suboptimal solutions; or regional optimization can be achieved to simultaneously considering certain portions of the tone levels. Also, interlocked threshold arrays can be created that obtain better data compression, or to embed a digital watermark.