Facsimile and static presentation processing – Static presentation processing – Attribute control
Patent
1988-11-08
1990-05-08
Groody, James J.
Facsimile and static presentation processing
Static presentation processing
Attribute control
358454, 358456, H04N 140
Patent
active
049243012
ABSTRACT:
Disclosed are apparatus and methods for producing halftone screens (color separations) from continuous tone intensity signals that are supplied by an optical scanner (12). A digital signal processor (10) processes the continuous tone intensity values to establish memory maps (18-6, 18-7, 18-8 and 18-10) which, in conjunction with a digital data output device (34) (e.g., a laser printer or a conventional image setter), produce the desired halftone screens. In producing halftone screens having a screen angle that does not substantially differ from 90.degree. (e.g., the 90.degree., 105.degree., and 75.degree. screen angles of the yellow, cyan and magenta color separations in conventional four color halftone printing), the digital signal processor (10) utilizes a dither matrix (FIG. 4) that is arranged to produce each halftone dot of the corresponding halftone screen at the desired screen ruling. In producing halftone screens having a screen angle that substantially differs from 90.degree. (e.g., the 45.degree. screen angle used in the black halftone color separation in conventional four color halftone printing), the digital signal processor (10) utilizes a dither array that properly positions the halftone dots of the resulting halftone screen and, in addition, establishes the desired screen ruling.
REFERENCES:
patent: 3911480 (1975-10-01), Brucker
patent: 4556918 (1985-12-01), Yamazaki
patent: 4644392 (1987-02-01), Yamada
patent: 4680625 (1987-07-01), Shoji
patent: 4700235 (1987-10-01), Gall
patent: 4783837 (1988-11-01), Kawamura
patent: 4809603 (1989-02-01), Moriguchi
"Basic Digital Imagining Concepts," Advertising Supplement to Macweek, Aug. 1988, pp. 18-19.
James D. Foley and Andries Van Dam, "Geometrical Transformations," Raster Algorithms and Software, Intensity and Color, Fundamentals of Interactive Computer Graphics, Addison-Wesley Publishing Company: Menlo Park, Calif., 1982.
Halftone, "Halftone Contact Screen," gray scale, dither, dither matrix, McGraw-Hill Dictionary of Scientific and Technical Terms, 2nd Ed., McGraw Hill Book Company, 1978.
Grant, II:
Groody James J.
SeeColor Corporation
LandOfFree
Apparatus and methods for digital halftoning does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and methods for digital halftoning, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and methods for digital halftoning will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2353149