Patent US6515768B1 successfully refreshed from Google Patents.
US6515768B1
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US
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Frequency modulation halfstone screen and method for making the same
Assignee: Agfa NV
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Filing: 1997-09-18
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Granted: 2003-02-04
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Expires: 2017-09-18
Abstract
Abstract A frequency-modulation halftone screen and method for making same, utilizing local randomization of a deterministic screen. The deterministic screen optimizes uniformity of the halftone dot distribution, while the local randomization suppresses artifacts due to subject moiré.
Inventors
- 👤 Frank A. Deschuytere
- 👤 Paul A. Delabastita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:41
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4051
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
46 words
A frequency-modulation halftone screen having a plurality of halftone dots, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen, said deterministic frequency-modulation screen for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level.
Claim 2
Dependent Claim
46 words
A frequency-modulation halftone screen having a plurality of halftone dots, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen, said deterministic frequency-modulation screen for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level.
Claim 3
Dependent Claim
38 words
The frequency-modulation halftone screen of claim 1 wherein the halftone dots lie on a grid, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 4
Dependent Claim
18 words
The frequency-modulation halftone screen of claim 1 wherein the halftone dots can take on more than two values.
Claim 5
Dependent Claim
17 words
The frequency-modulation halftone screen of claim 1 wherein the halftone dots can have more than one size.
Claim 6
Dependent Claim
41 words
A frequency-modulation halftone screen having a screen function that is a locally-randomized deterministic frequency-modulation screen function, said deterministic frequency-modulation screen function for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level.
Claim 7
Dependent Claim
41 words
A frequency-modulation halftone screen having a screen function that is a locally-randomized deterministic frequency-modulation screen function, said deterministic frequency-modulation screen function for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level.
Claim 8
Dependent Claim
17 words
The frequency-modulation halftone screen of claim 5 wherein the frequency-modulation screen function is a Bayer dither matrix.
Claim 9
Dependent Claim
39 words
The frequency-modulation halftone screen of claim 5 wherein the screen function values lie on a grid, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 10
Dependent Claim
19 words
The frequency-modulation halftone screen of claim 5 wherein the screen function values can take on more than two values.
Claim 11
Dependent Claim
18 words
The frequency-modulation halftone screen of claim 5 wherein the screen function values can have more than one size.
Claim 12
Dependent Claim
53 words
A frequency-modulation halftone screen having a plurality of halftone dots and a locally-randomized frequency-modulation screen that produces at any tone level a maximum uniformity of the halftone dot distribution with the screen, wherein said halftone dots have a fixed dot size and have a distance between halftone dots, modulated according to tone level.
Claim 13
Dependent Claim
53 words
A frequency-modulation halftone screen having a plurality of halftone dots and a locally-randomized frequency-modulation screen that produces at any tone level a maximum uniformity of the halftone dot distribution with the screen, wherein said halftone dots have a fixed dot size and have a distance between halftone dots, modulated according to tone level.
Claim 14
Dependent Claim
38 words
The frequency-modulation halftone screen of claim 10 wherein the halftone dots lie on a grid, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 15
Dependent Claim
18 words
The frequency-modulation halftone screen of claim 10 wherein the halftone dots can take on more than two values.
Claim 16
Dependent Claim
17 words
The frequency-modulation halftone screen of claim 10 wherein the halftone dots can have more than one size.
Claim 17
Independent Claim
62 words
A method for producing a frequency-modulation halftone screen comprising the steps of: (A) generating a deterministic frequency-modulation screen function for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level; (B) locally randomizing said deterministic frequency-modulation screen function; and, (C) utilizing said locally-randomized deterministic frequency-modulation screen function to produce the frequency-modulation halftone screen.
Claim 18
Independent Claim
62 words
A method for producing a frequency-modulation halftone screen comprising the steps of: (A) generating a deterministic frequency-modulation screen function for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level; (B) locally randomizing said deterministic frequency-modulation screen function; and, (C) utilizing said locally-randomized deterministic frequency-modulation screen function to produce the frequency-modulation halftone screen.
Claim 19
Dependent Claim
17 words
The method of claim 14 wherein the generated deterministic frequency-modulation screen function is a Bayer dither matrix.
Claim 20
Dependent Claim
55 words
The method of claim 14 wherein the local randomization of the deterministic frequency-modulation screen function is obtained by subdividing the frequency-modulation screen function into a plurality of parcels with each of said parcels having a plurality of screen function values, and then permuting the positions of said screen function values within each of said parcels.
Claim 21
Dependent Claim
75 words
The method of claim 14 wherein the local randomization comprises the following steps: (A) subdividing the deterministic frequency-modulation screen function into a plurality of parcels each having a plurality of screen function values; (B) subdividing each of said plurality of parcels into subparcels; (C) randomly permuting the positions of said subparcels within said parcels; and, (D) repeating steps (B) and (C) recursively for each subparcel until a subparcel comprises only a single screen function element.
Claim 22
Dependent Claim
17 words
The method of claim 14 wherein the screen function values can take on more than two values.
Claim 23
Dependent Claim
38 words
(Amended) The method of claim 14 wherein the screen function values lie on a grid, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 24
Dependent Claim
16 words
The method of claim 14 wherein the screen function values can have more than one size.
Claim 25
Independent Claim
59 words
A method for producing a frequency-modulation halftone screen comprising the steps of: (A) generating a deterministic frequency-modulation screen for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level; (B) locally randomizing said deterministic frequency-modulation screen; and, (C) utilizing said locally-randomized deterministic frequency-modulation screen to produce the frequency-modulation halftone screen.
Claim 26
Independent Claim
59 words
A method for producing a frequency-modulation halftone screen comprising the steps of: (A) generating a deterministic frequency-modulation screen for producing halftone dots with a fixed dot size and a distance between halftone dots, modulated according to tone level; (B) locally randomizing said deterministic frequency-modulation screen; and, (C) utilizing said locally-randomized deterministic frequency-modulation screen to produce the frequency-modulation halftone screen.
Claim 27
Dependent Claim
18 words
The method of claim 21 wherein the generated deterministic frequency-modulation screen is obtained from a Bayer dither matrix.
Claim 28
Dependent Claim
51 words
The method of claim 21 wherein the local randomization of the deterministic frequency-modulation screen is obtained by subdividing the frequency-modulation screen into a plurality of parcels with each of said parcels having a plurality of halftone dots, and then permuting the positions of said halftone dots within each of said parcels.
Claim 29
Dependent Claim
71 words
The method of claim 21 wherein the local randomization comprises the following steps: (A) subdividing the deterministic frequency-modulation screen into a plurality of parcels each having a plurality of halftone dots; (B) subdividing each of said plurality of parcels into subparcels; (C) randomly permuting the positions of said subparcels within said parcels; and, (D) repeating steps (B) and (C) recursively for each subparcel until a subparcel comprises only a halftone dot.
Claim 30
Dependent Claim
49 words
A frequency-modulation halftone screen having a plurality of halftone dots lying on a grid, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 31
Dependent Claim
49 words
A frequency-modulation halftone screen having a plurality of halftone dots lying on a grid, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 32
Dependent Claim
30 words
A frequency-modulation halftone screen having a plurality of halftone dots which can take on more than two values, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen.
Claim 33
Dependent Claim
30 words
A frequency-modulation halftone screen having a plurality of halftone dots which can take on more than two values, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen.
Claim 34
Dependent Claim
29 words
A frequency-modulation halftone screen having a plurality of halftone dots which can have more than one size, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen.
Claim 35
Dependent Claim
29 words
A frequency-modulation halftone screen having a plurality of halftone dots which can have more than one size, said halftone dots being obtained by locally randomizing a deterministic frequency-modulation screen.
Claim 36
Dependent Claim
25 words
A frequency-modulation halftone screen having a screen function that is a locally-randomized deterministic frequency-modulation screen function, wherein the screen function is a Bayer dither matrix.
Claim 37
Dependent Claim
25 words
A frequency-modulation halftone screen having a screen function that is a locally-randomized deterministic frequency-modulation screen function, wherein the screen function is a Bayer dither matrix.
Claim 38
Dependent Claim
49 words
A frequency-modulation halftone screen having a screen function that is a locally-randomized deterministic frequency-modulation screen function, the screen function having values which lie on a grid, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 39
Dependent Claim
49 words
A frequency-modulation halftone screen having a screen function that is a locally-randomized deterministic frequency-modulation screen function, the screen function having values which lie on a grid, wherein the grid is selected from the group consisting of a square grid, a rectangular grid, a hexagonal grid, and a non-periodic grid.
Claim 40
Independent Claim
51 words
A method for producing a frequency-modulation halftone screen comprising the steps of: (A) generating a deterministic frequency-modulation screen function, wherein the screen function is a Bayer dither matrix; (B) locally randomizing said deterministic frequency-modulation screen function; and, (C) utilizing said locally-randomized deterministic frequency-modulation screen function to produce the frequency-modulation halftone screen.
Claim 41
Independent Claim
51 words
A method for producing a frequency-modulation halftone screen comprising the steps of: (A) generating a deterministic frequency-modulation screen function, wherein the screen function is a Bayer dither matrix; (B) locally randomizing said deterministic frequency-modulation screen function; and, (C) utilizing said locally-randomized deterministic frequency-modulation screen function to produce the frequency-modulation halftone screen.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2006-02-03 | 2006-08-05 | 2007-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-02-03 | 2010-08-05 | 2011-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-02-03 | 2014-08-05 | 2015-02-04 | $7700.00 | Window Closed / Lapsed |