US4706077A
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Halftoning implementation for interactive image editing
Assignee: Xerox Corp
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Filing: 1981-09-08
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Granted: 1987-11-10
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Expires: 2001-09-08
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
- 👤 Zoltan Stroll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:35
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/4051
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
57 words
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
Independent Claim
57 words
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
58 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
58 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.
Claim 11
Dependent Claim
43 words
A three by three element halftone matrix comprising: a set of nine numerically ascending or descending threshold values, the elements of said matrix numbered, row by row, as follows: 6, 9,4,3,1,7,8,5,2, said set of threshold values assigned to said matrix in numerical order.
Claim 12
Dependent Claim
43 words
A three by three element halftone matrix comprising: a set of nine numerically ascending or descending threshold values, the elements of said matrix numbered, row by row, as follows: 6, 9,4,3,1,7,8,5,2, said set of threshold values assigned to said matrix in numerical order.
Claim 13
Dependent Claim
45 words
A six by six element halftone matrix comprising a set of 36 numerically ascending or descending values, the elements of said matrix numbered, 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, and 6, said set of threshold values assigned to said matrix in numerical order.
Claim 14
Dependent Claim
45 words
A six by six element halftone matrix comprising a set of 36 numerically ascending or descending values, the elements of said matrix numbered, 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, and 6, said set of threshold values assigned to said matrix in numerical order.
Claim 15
Dependent Claim
23 words
A three by three element halftone matrix comprising numerically ascending or descending threshold values assigned to said matrix in a knight tour pattern.
Claim 16
Dependent Claim
23 words
A three by three element halftone matrix comprising numerically ascending or descending threshold values assigned to said matrix in a knight tour pattern.
Claim 17
Dependent Claim
28 words
A six by six element halftone matrix comprising a set of thirty-six numerically ascending or descending threshold values assigned to said matrix in a knight ordered dither pattern.
Claim 18
Dependent Claim
28 words
A six by six element halftone matrix comprising a set of thirty-six numerically ascending or descending threshold values assigned to said matrix in a knight ordered dither pattern.
Claim 19
Dependent Claim
30 words
A nine by nine element halftone matrix comprising a set of eighty-one numerically ascending or descending threshold values, assigned to said matrix in a two level nested knight tour pattern.
Claim 20
Dependent Claim
30 words
A nine by nine element halftone matrix comprising a set of eighty-one numerically ascending or descending threshold values, assigned to said matrix in a two level nested knight tour pattern.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |