US5384648A
Expired / Lapsed
US
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Apparatus and method for descreening
Assignee: Kodak IL Ltd
•
Filing: 1994-01-06
•
Granted: 1995-01-24
•
Expires: 2014-01-06
Abstract
Abstract Apparatus and method for descreening and for performing resolution changes and correction of misregistration on a color half-tone image in order to produce a color continuous tone image. The apparatus includes filter apparatus for removing screen information from the half-tone image including a plurality of different filters each providing interpolation and screen removal functions and a controller for selecting per pixel of the continuous tone image and in accordance with sensed misregistration and as a function of desired resolution changes, one of the filters for operation on a neighborhood of the pixel.
Inventors
- 👤 Daniel Seidner
- 👤 Dan Eylon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:19
CPC Classifications
G; G06; G06T; G06T3/00; G06T3/40; G06T3/4007; H; H04; H04N; H04N1/00; H04N1/40; H04N1/40075; H04N1/46; H04N1/56; H04N1/58
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
90 words
Apparatus for descreening and for performing correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations comprising: means for sensing said misregistration; filter means for removing screen information from said half-tone image comprising a plurality of different filters each providing interpolation and screen removal functions; and a controller for selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration, one of said filters for operation on a neighborhood of said pixel.
Claim 2
Dependent Claim
90 words
Apparatus for descreening and for performing correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations comprising: means for sensing said misregistration; filter means for removing screen information from said half-tone image comprising a plurality of different filters each providing interpolation and screen removal functions; and a controller for selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration, one of said filters for operation on a neighborhood of said pixel.
Claim 3
Dependent Claim
20 words
Apparatus according to claim 1 and wherein said interpolation functions are provided by a plurality of frequency domain phase shifts.
Claim 4
Dependent Claim
19 words
Apparatus according to claim 1 and wherein said interpolation functions are provided by a plurality of sampled interpolation functions.
Claim 5
Dependent Claim
21 words
Apparatus according to claim 1 and wherein said controller includes means for performing resolution changes on each of said half-tone separations.
Claim 6
Dependent Claim
17 words
Apparatus according to claim 1 and wherein each of said filters is applied in a spatial domain.
Claim 7
Dependent Claim
39 words
Apparatus according to claim 1 and wherein said screen removal functions are provided by screen removal filter means for removing the entirety of frequencies at and above a predetermined frequency, wherein said frequency is a function of screen parameters.
Claim 8
Dependent Claim
26 words
Apparatus according to claim 1 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency and its harmonics.
Claim 9
Dependent Claim
24 words
Apparatus according to claim 1 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency only.
Claim 10
Dependent Claim
68 words
Apparatus according to claim 1 and wherein said controller comprises: means for calculating the location of a next pixel in said continuous tone image; means for choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image; and means for selecting one of said filters in accordance with said location on said predefined grid.
Claim 11
Independent Claim
94 words
A method for descreening and for performing correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations including the steps of: sensing said misregistration; and removing screen information from said half-tone image via a plurality of different filters each providing interpolation and screen removal functions; said step of removing including the step of selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration, one of said filters for operation on a neighborhood of said pixel.
Claim 12
Independent Claim
94 words
A method for descreening and for performing correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations including the steps of: sensing said misregistration; and removing screen information from said half-tone image via a plurality of different filters each providing interpolation and screen removal functions; said step of removing including the step of selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration, one of said filters for operation on a neighborhood of said pixel.
Claim 13
Dependent Claim
21 words
A method according to claim 10 and wherein said interpolation functions are provided by a plurality of frequency domain phase shifts.
Claim 14
Dependent Claim
20 words
A method according to claim 10 and wherein said interpolation functions are provided by a plurality of sampled interpolation functions.
Claim 15
Dependent Claim
20 words
A method according to claim 10 and wherein said step of removing screen information is performed in a spatial domain.
Claim 16
Dependent Claim
41 words
A method according to claim 10 and wherein said screen removal functions are provided by screen removal filter means for removing the entirety of frequencies at and above a predetermined frequency, wherein said frequency is a function of said screen frequency.
Claim 17
Dependent Claim
27 words
A method according to claim 10 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency and its harmonics.
Claim 18
Dependent Claim
25 words
A method according to claim 10 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency only.
Claim 19
Dependent Claim
68 words
A method according to claim 10 and wherein said step of selecting includes the steps of: calculating the location of a next pixel in said continuous tone image; choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image; and selecting one of said filters in accordance with said location on said predefined grid.
Claim 20
Dependent Claim
101 words
Apparatus for descreening and for performing resolution changes and correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations comprising: means for sensing said misregistration; filter means for removing screen information from said half-tone image comprising a plurality of different filters each providing interpolation and screen removal functions; and a controller for selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration and as a function of desired resolution changes, one of said filters for operation on a neighborhood of said pixel.
Claim 21
Dependent Claim
101 words
Apparatus for descreening and for performing resolution changes and correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations comprising: means for sensing said misregistration; filter means for removing screen information from said half-tone image comprising a plurality of different filters each providing interpolation and screen removal functions; and a controller for selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration and as a function of desired resolution changes, one of said filters for operation on a neighborhood of said pixel.
Claim 22
Dependent Claim
20 words
Apparatus according to claim 18 and wherein said interpolation functions are provided by a plurality of frequency domain phase shifts.
Claim 23
Dependent Claim
19 words
Apparatus according to claim 18 and wherein said interpolation functions are provided by a plurality of sampled interpolation functions.
Claim 24
Dependent Claim
17 words
Apparatus according to claim 18 and wherein each of said filters is applied in a spatial domain.
Claim 25
Dependent Claim
39 words
Apparatus according to claim 18 and wherein said screen removal functions are provided by screen removal filter means for removing the entirety of frequencies at and above a predetermined frequency, wherein said frequency is a function of screen parameters.
Claim 26
Dependent Claim
26 words
Apparatus according to claim 18 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency and its harmonics.
Claim 27
Dependent Claim
24 words
Apparatus according to claim 18 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency only.
Claim 28
Dependent Claim
68 words
Apparatus according to claim 18 and wherein said controller comprises: means for calculating the location of a next pixel in said continuous tone image; means for choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image; and means for selecting one of said filters in accordance with said location on said predefined grid.
Claim 29
Independent Claim
105 words
A method for descreening and for performing resolution changes and correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations including the steps of: sensing said misregistration; and removing screen information from said half-tone image via a plurality of different filters each providing interpolation and screen removal functions; said step of removing including the step of selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration and as a function of desired resolution changes, one of said filters for operation on a neighborhood of said pixel.
Claim 30
Independent Claim
105 words
A method for descreening and for performing resolution changes and correction of misregistration between at least two half-tone image separations in order to produce at least two continuous tone image separations including the steps of: sensing said misregistration; and removing screen information from said half-tone image via a plurality of different filters each providing interpolation and screen removal functions; said step of removing including the step of selecting, per pixel of each of said continuous tone image separations and in accordance with said sensed misregistration and as a function of desired resolution changes, one of said filters for operation on a neighborhood of said pixel.
Claim 31
Dependent Claim
21 words
A method according to claim 26 and wherein said interpolation functions are provided by a plurality of frequency domain phase shifts.
Claim 32
Dependent Claim
20 words
A method according to claim 26 and wherein said interpolation functions are provided by a plurality of sampled interpolation functions.
Claim 33
Dependent Claim
130 words
A method according to claim 26 and wherein said step of misregistration includes the steps of: prescanning at least one first portion of a first separation to provide a first digital representation; prescanning at least one second portion of a second separation to provide a second digital representation, said first and second portions being in the same location on said first and second separations; cross-correlating said first and second digital representations to provide a cross-correlation array; identifying a location of a maximum value of said cross-correlation array wherein said maximum value is a pixel-level maximum value; and from said pixel-level maximum value and from cross-correlation values of its neighbors, estimating a location of a sub-pixel maximum value between said location of said pixel-level maximum value and locations of its neighbors.
Claim 34
Dependent Claim
20 words
A method according to claim 26 and wherein said step of removing screen information is performed in a spatial domain.
Claim 35
Dependent Claim
41 words
A method according to claim 26 and wherein said screen removal functions are provided by screen removal filter means for removing the entirety of frequencies at and above a predetermined frequency, wherein said frequency is a function of said screen frequency.
Claim 36
Dependent Claim
27 words
A method according to claim 26 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency and its harmonics.
Claim 37
Dependent Claim
25 words
A method according to claim 26 and wherein said screen removal functions are provided by screen removal filter means for removing a screen frequency only.
Claim 38
Dependent Claim
68 words
A method according to claim 26 and wherein said step of selecting includes the steps of: calculating the location of a next pixel in said continuous tone image; choosing a location on a predefined grid closest to said location of said next pixel, said predefined grid being defined on said continuous tone image; and selecting one of said filters in accordance with said location on said predefined grid.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-23 | 1998-07-25 | 1999-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-23 | 2002-07-25 | 2003-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-23 | 2006-07-25 | 2007-01-24 | $7700.00 | Window Closed / Lapsed |