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Proceedings Paper

High-speed multilevel halftoning hardware
Author(s): Michael Thomas Brady; Charles H. Morris; Joan L. Mitchell
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Paper Abstract

A high speed multilevel color printer required custom halftoning hardware. For this multitone environment we revised traditional halftone thresholding (i.e. turning the output from no intensity to full intensity). Unfortunately, intermediate values did not print large areas reliably. Legacy image data files existed that were already halftoned. To correct these problems, binary halftone methods were modified to produce multi-bit outputs. This was accomplished by using threshold matrices to determine when to allow printing. The input minus the threshhold value was used to index into a lookup table to select the output intensity. Design of the down-loadable threshold matrices solved the print consistency problem. The custom hardware ensured that a zero input value did not print and a maximum value printed as a saturated output. These solutions were implemented using custom high-speed logic capable of outputting 66 MegaPels/sec.

Paper Details

Date Published: 28 December 2001
PDF: 7 pages
Proc. SPIE 4663, Color Imaging: Device-Independent Color, Color Hardcopy, and Applications VII, (28 December 2001); doi: 10.1117/12.452996
Show Author Affiliations
Michael Thomas Brady, IBM Corp. (United States)
Charles H. Morris, IBM Corp. (United States)
Joan L. Mitchell, IBM Thomas J. Watson Research Ctr. (United States)


Published in SPIE Proceedings Vol. 4663:
Color Imaging: Device-Independent Color, Color Hardcopy, and Applications VII
Reiner Eschbach; Gabriel G. Marcu, Editor(s)

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