US5488491A
Expired / Lapsed
US
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Image processing apparatus and method for eliminating background density in a designated image area
Assignee: Eastman Kodak Co
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Filing: 1993-07-06
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Granted: 1996-01-30
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Expires: 2013-07-06
Abstract
Abstract A reproduction apparatus such as one having an electronic electrophotographic marking engine includes an image scanning device for scanning and outputting signals representing image density data on a document. An area designating device such as a digitizing tablet is provided for generating signals representing information relative to a selected image area of the document containing both foreground and background density. A processor is responsive to the density and area signals for operating on the image data in the area to define clipping signals representing parameters for substantially eliminating the background density while substantially preserving information with foreground density.
Inventors
- 👤 James J. Steinkirchner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:33
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407; H04N1/403
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
226 words
An electrostatographic reproduction apparatus comprising: scanning means for scanning and outputting first signals representing intensity variations in an original image on a document sheet; designating means for generating second signals representing information relative to a determined image area of the document sheet containing both foreground information and background density; area operation means responsive to the first and second signals for generating third signals representing parameters for substantially eliminating the background density while substantially preserving information with foreground density; and an electrostatographic marking engine including means responsive to said third signals for reproducing a copy of the document sheet with the foreground information without the background density in the area corresponding to the determined area; and wherein the area operation means includes: means for generating a histogram of pixel densities and their frequencies for pixels residing within the determined image area; means for subjecting data in said histogram to a low pass filter and outputting filtered data; means for determining a slope of points in said filtered data; means for defining a geometric minimum within a predetermined amount of a statistical average of the histogram data; means for determining geometric maximums on each side of the geometric minimum; and means for comparing a maximum on one side with a maximum on the other side and defining said parameters if one particular maximum is greater than the other.
Claim 2
Dependent Claim
226 words
An electrostatographic reproduction apparatus comprising: scanning means for scanning and outputting first signals representing intensity variations in an original image on a document sheet; designating means for generating second signals representing information relative to a determined image area of the document sheet containing both foreground information and background density; area operation means responsive to the first and second signals for generating third signals representing parameters for substantially eliminating the background density while substantially preserving information with foreground density; and an electrostatographic marking engine including means responsive to said third signals for reproducing a copy of the document sheet with the foreground information without the background density in the area corresponding to the determined area; and wherein the area operation means includes: means for generating a histogram of pixel densities and their frequencies for pixels residing within the determined image area; means for subjecting data in said histogram to a low pass filter and outputting filtered data; means for determining a slope of points in said filtered data; means for defining a geometric minimum within a predetermined amount of a statistical average of the histogram data; means for determining geometric maximums on each side of the geometric minimum; and means for comparing a maximum on one side with a maximum on the other side and defining said parameters if one particular maximum is greater than the other.
Claim 3
Dependent Claim
19 words
The apparatus of claim 1 and wherein the third signals representing said parameters define a video clip look-up table.
Claim 4
Dependent Claim
19 words
The apparatus of claim 1 and wherein the third signals representing said parameters define a video shift look-up table.
Claim 5
Dependent Claim
28 words
The apparatus of claim 1 and including means responsive to said first signals, second signals and third signals for generating fourth signals for output to a marking engine.
Claim 6
Dependent Claim
21 words
The apparatus of claim 4 and wherein pixels not within said determined image area are not input to said memory means.
Claim 7
Dependent Claim
15 words
The apparatus of claim 5 and wherein the marking engine is an electrostatographic marking engine.
Claim 8
Dependent Claim
25 words
The apparatus of claim 6 and wherein the marking engine includes an electronic print source that modulates light with image data to record an image.
Claim 9
Dependent Claim
208 words
An image processing apparatus comprising: scanning means for scanning and outputting first signals representing image data as determined by sensing intensity variations in an original image; area designating means for generating second signals representing information relative to a determined image area of the document containing both foreground and background density; area operation means responsive to the first and second signals for operating on the image data in the area to define third signals representing parameters for substantially eliminating the background density while substantially preserving information with foreground density; and memory means for storing said third signals; and wherein the area operation means includes; means for generating a histogram of pixel densities and their frequencies for pixels residing within the determined image area; means for subjecting data in said histogram to a low pass filter and outputting filtered data; means for determining a slope of points in said filtered data; means for defining a geometric minimum within a predetermined amount of a statistical average of the histogram data; means for determining geometric maximums on each side of the geometric minimum; and means for comparing a maximum on one side with a maximum on the other side and defining said parameters if one particular maximum is greater than the other.
Claim 10
Dependent Claim
208 words
An image processing apparatus comprising: scanning means for scanning and outputting first signals representing image data as determined by sensing intensity variations in an original image; area designating means for generating second signals representing information relative to a determined image area of the document containing both foreground and background density; area operation means responsive to the first and second signals for operating on the image data in the area to define third signals representing parameters for substantially eliminating the background density while substantially preserving information with foreground density; and memory means for storing said third signals; and wherein the area operation means includes; means for generating a histogram of pixel densities and their frequencies for pixels residing within the determined image area; means for subjecting data in said histogram to a low pass filter and outputting filtered data; means for determining a slope of points in said filtered data; means for defining a geometric minimum within a predetermined amount of a statistical average of the histogram data; means for determining geometric maximums on each side of the geometric minimum; and means for comparing a maximum on one side with a maximum on the other side and defining said parameters if one particular maximum is greater than the other.
Claim 11
Dependent Claim
19 words
The apparatus of claim 8 and wherein the third signals representing said parameters define a video clip look-up table.
Claim 12
Dependent Claim
19 words
The apparatus of claim 8 and wherein the third signals representing said parameters define a video shift look-up table.
Claim 13
Dependent Claim
29 words
The apparatus of claim 8 and including means for responsive to said first signals, second signals and third signals for generating fourth signals for output to a marking engine.
Claim 14
Dependent Claim
21 words
The apparatus of claim 11 and wherein pixels not within said determined image area are not input to said memory means.
Claim 15
Dependent Claim
15 words
The apparatus of claim 12 and wherein the marking engine is an electrostatographic marking engine.
Claim 16
Dependent Claim
25 words
The apparatus of claim 13 and wherein the marking engine includes an electronic print source that modulates light with image data to record an image.
Claim 17
Dependent Claim
21 words
The apparatus of claim 8 and wherein pixels not within said determined image area are not input to electrostatographic marking engine.
Claim 18
Dependent Claim
203 words
An image processing method comprising: scanning image data on a document and outputting first signals representing intensity variations in an original image; designating an image area of the document containing both foreground and background density and generating second signals representing said area; in response to the first and second signals operating on the image data in the area to define third signals representing parameters for substantially eliminating the background density while substantially preserving information with foreground density and printing a reproduction of image data on the document with the foreground information reproduced but background density in the original of the designated area eliminated; and wherein the step of operating includes; generating a histogram of pixel densities and their frequencies for pixels residing within the determined image area; subjecting data in said histogram to a low pass filter and generating filtered data; determining a slope of points in said filtered data; defining a geometric minimum within a predetermined amount from a statistical average of the histogram data; determining geometric maximums one each side of the geometric minimum; and comparing a maximum on one side with a maximum on the other side and defining said parameters if one particular maximum is greater than the other.
Claim 19
Dependent Claim
203 words
An image processing method comprising: scanning image data on a document and outputting first signals representing intensity variations in an original image; designating an image area of the document containing both foreground and background density and generating second signals representing said area; in response to the first and second signals operating on the image data in the area to define third signals representing parameters for substantially eliminating the background density while substantially preserving information with foreground density and printing a reproduction of image data on the document with the foreground information reproduced but background density in the original of the designated area eliminated; and wherein the step of operating includes; generating a histogram of pixel densities and their frequencies for pixels residing within the determined image area; subjecting data in said histogram to a low pass filter and generating filtered data; determining a slope of points in said filtered data; defining a geometric minimum within a predetermined amount from a statistical average of the histogram data; determining geometric maximums one each side of the geometric minimum; and comparing a maximum on one side with a maximum on the other side and defining said parameters if one particular maximum is greater than the other.
Claim 20
Dependent Claim
21 words
The method of claim 20 and wherein the third signals representing said parameters are stored as a video clip look-up table.
Claim 21
Dependent Claim
21 words
The method of claim 20 and wherein the third signals representing said parameters are stored as a video shift look-up table.
Claim 22
Dependent Claim
21 words
The method of claim 16 and wherein the printing is done by a marking engine that is an electrostatographic marking engine.
Claim 23
Dependent Claim
25 words
The apparatus of claim 6 and wherein the marking engine includes an electronic print source that modulates light with image data to record an image.
Claim 24
Dependent Claim
31 words
The apparatus of claim 20 and wherein the marking engine is a grey level marking engine that forms pixels of varying grey levels in accordance with a multibit image data signal.
Claim 25
Dependent Claim
31 words
The method of claim 19 and wherein the marking engine is a grey level marking engine that forms pixels of varying grey levels in accordance with a multibit image data signal.
Claim 26
Dependent Claim
47 words
The method of claim 17 and wherein in response to said third signals and said first signals, a multibit signal is defined for each pixel to be printed by a grey level marking engine, and printing pixels of varying grey levels by said grey level marking engine.
Claim 27
Dependent Claim
47 words
The method of claim 18 and wherein in response to said third signals and said first signals, a multibit signal is defined for each pixel to be printed by a grey level marking engine, and printing pixels of varying grey levels by said grey level marking engine.
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) | 1999-01-29 | 1999-07-31 | 2000-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-29 | 2003-07-31 | 2004-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-29 | 2007-07-31 | 2008-01-30 | $7700.00 | Window Closed / Lapsed |