Method and apparatus for halftone rendering of a gray scale image using a blue noise mask
Patent 5341228 Issued on August 23, 1994. Estimated Expiration Date: 
December 3, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 3, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesTechnique for interpolating a color image for image enlargement or reduction based on look-up tables stored in memory Digital image processing apparatus Halftone imaging method and apparatus utilizing pyramidol error convergence Method and apparatus for halftone rendering of a gray scale image using a blue noise mask Patent #: 5111310 InventorsAssigneeApplicationNo. 801921 filed on 12/03/1991US Classes:358/534, Halftone processing358/3.19, Stochastic or random dithering358/465, Picture signal thresholding358/523, With memory for storage of conversion data358/536Halftone screeningExaminersPrimary: Coles, Sr., Edward L.Assistant: Lee, Fan Attorney, Agent or FirmInternational ClassH04N 001/46AbstractA 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 corresponding data points contained in a blue noise mask stored in a PROM or computer memory in order to produce the desired halftoned image. Both digital and optically implemented halftone methods are disclosed. Application specific modifications of the blue noise mask as well as its use for producing halftoned color images are also disclosed. | |
