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EP0199469A2
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Method for assigning values to a half-tone threshold matrix
Assignee: Xerox Corp
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Filing: 1982-09-08
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Granted: —
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Expires: 2002-09-08
Abstract
Abstract A circuit for producing a "knight ordered dither" halftone pattern for a CRT and a "double spiral" halftone pattern for a xerographic printer is described. The circuit comprises a RAM for storing the threshold values, a comparator, and supporting addressing and logic parts. Also described are a program for allowing the operator to interactively generate threshold patterns, and several knight tour patterns specifically designed for a CRT using interlaced rasters.
Inventors
- 👤 Allen M. Roberts
- 👤 Andrew Sangster
- 👤 Zolton Stroll
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 08:46
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/4051
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
67 words
1 . The method of assigning threshold values to each element of a 3 by 3 element halftone matrix comprising the steps of: determining a set of nine numerically ascending or descending threshold values, numbering the elements of said matrix, row by row, as follows: 6, 9, 4, 3, 1, 7, 8, 5, 2, and assigning said set of threshold values to said matrix in numerical order.
Claim 2
Dependent Claim
67 words
1 . The method of assigning threshold values to each element of a 3 by 3 element halftone matrix comprising the steps of: determining a set of nine numerically ascending or descending threshold values, numbering the elements of said matrix, row by row, as follows: 6, 9, 4, 3, 1, 7, 8, 5, 2, and assigning said set of threshold values to said matrix in numerical order.
Claim 3
Independent Claim
92 words
The method of assigning threshold values to each element of a 6 by 6 element halftone matrix comprising the steps of: determining a set of 36 numerically ascending or descending threshold values, numbering the elements of said matrix, row by row, as follows: 21, 33, 13, 23, 35, 15, 9, 1, 25, 11, 3, 27, 29, 17, 5, 31, 19, 7, 24, 36, 16, 22, 34, 14, 12, 4, 28, 10, 2, 26, 32, 20, 8, 30, 18, 6 and assigning said set of threshold values to said matrix in numerical order.
Claim 4
Independent Claim
92 words
The method of assigning threshold values to each element of a 6 by 6 element halftone matrix comprising the steps of: determining a set of 36 numerically ascending or descending threshold values, numbering the elements of said matrix, row by row, as follows: 21, 33, 13, 23, 35, 15, 9, 1, 25, 11, 3, 27, 29, 17, 5, 31, 19, 7, 24, 36, 16, 22, 34, 14, 12, 4, 28, 10, 2, 26, 32, 20, 8, 30, 18, 6 and assigning said set of threshold values to said matrix in numerical order.
Claim 5
Independent Claim
44 words
The method of assigning threshold values to each element of a three by three element halftone matrix comprising the steps of: determining a set of nine numerically ascending or descending threshold values, and assigning these values to said matrix in a knight tour pattern.
Claim 6
Independent Claim
44 words
The method of assigning threshold values to each element of a three by three element halftone matrix comprising the steps of: determining a set of nine numerically ascending or descending threshold values, and assigning these values to said matrix in a knight tour pattern.
Claim 7
Independent Claim
45 words
The method of assigning threshold values to each element of a six by six element halftone matrix comprising the steps of: determining a set of thirty-six numerically ascending or descending threshold values, and assigning these values to said matrix in a knight ordered dither pattern.
Claim 8
Independent Claim
45 words
The method of assigning threshold values to each element of a six by six element halftone matrix comprising the steps of: determining a set of thirty-six numerically ascending or descending threshold values, and assigning these values to said matrix in a knight ordered dither pattern.
Claim 9
Independent Claim
47 words
The method of assigning threshold values to each element of a nine by nine element halftone matrix comprising the steps of: determining a set of eighty-one numerically ascending or descending threshold values, and assigning these values to said matrix in a two level nested knight tour pattern.
Claim 10
Independent Claim
47 words
The method of assigning threshold values to each element of a nine by nine element halftone matrix comprising the steps of: determining a set of eighty-one numerically ascending or descending threshold values, and assigning these values to said matrix in a two level nested knight tour pattern.
References Cited (Backward Citations)
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