EP0352016A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and system for enhancement of a digitized image
Assignee: 3M Co
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Filing: 1989-07-13
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Granted: —
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Expires: 2009-07-13
Abstract
Abstract A system and method of modifying pixels supplied to the system that a multiple level signals for a digitized image wherein a moving pixel window (16) with a center pixel, D c , is used from which the annular means, m a , of the center pixel (the mean of the 2 N pixel values of the window surrounding the center pixel, where N is an integer of 1 or more) is determined with the center pixel and selected pixels surrounding the center pixel, D c , are used to establish a modification gain, g, or determine a measure of deviation (center deviation, σ c ) of the center pixel relative to the center pixel that is used to obtain a modification gain, f(σ c ,C g ) of f,(σ,C g ). The center pixel, D c , its annular mean, m a , and its modification gain, g, f(σ c ,C g ) or f′(σ c ,C g ) are used to obtain a modified center pixel value, D c ′, in accordance with one of the following equations that are of the form for an algorithm for determining the unsharp masking filter value for an image pixel: D c ′ = [g x (D c - m a )] = m a ; or D c ′ = f(σ c ,C g ) x (D c - m a )] + m a ; or where n is an integer of 0 or greater.
Inventors
- 👤 Terrence H. C/O Minnesota Mining And Joyce
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 13:04
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/73; G06T5/75; G06T5/20
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
162 words
A system for modifying pixels supplied to the system that are multiple level signals for a digitized image wherein: a means (6, 12, 14) provides a moving pixel window (16) from pixels supplied to the system, said pixel window having a center pixel, D c , and at least 2 N pixels surrounding said center pixel, wherein N is an integer of 1 or more; a means (18) receives 2 N of said pixels surrounding said center pixel and provides the annular mean, m a , of said received 2 N pixels; and a means (20, 22, 24) receives said center pixel, D c , and selected pixels of said pixel window (16) surrounding said center pixel for providing a modification gain, g, and receives said annular means, m a , for providing a modified center pixel, D c ′, in accordance with the following equation: D c ′ = [g x (D c - m a )] + m a .
Claim 2
Independent Claim
162 words
A system for modifying pixels supplied to the system that are multiple level signals for a digitized image wherein: a means (6, 12, 14) provides a moving pixel window (16) from pixels supplied to the system, said pixel window having a center pixel, D c , and at least 2 N pixels surrounding said center pixel, wherein N is an integer of 1 or more; a means (18) receives 2 N of said pixels surrounding said center pixel and provides the annular mean, m a , of said received 2 N pixels; and a means (20, 22, 24) receives said center pixel, D c , and selected pixels of said pixel window (16) surrounding said center pixel for providing a modification gain, g, and receives said annular means, m a , for providing a modified center pixel, D c ′, in accordance with the following equation: D c ′ = [g x (D c - m a )] + m a .
Claim 3
Dependent Claim
132 words
A system according to claim 1 wherein said last-mentioned means includes: a means (20) receiving said center pixel and selected pixels of said pixel window surrounding said center pixel for providing an output (47) based on the center deviation σ c , for said center pixel; and a means (22) connected to said output (47) for obtaining a modification gain, f(σ c , C g ) as the modification gain, g; and a means (24) receiving said center pixel, D c , said annular means, m a , and said modification gain, f(σ c ,C g ) for providing a modified center pixel, D c ′, in accordance with the following equation: D c ′ = [f(σ c ,C g ) x (D c - m a )] + m a .
Claim 4
Dependent Claim
120 words
A system according to claim 1 wherein said last-mentioned means includes: a means (20) receiving said center pixel and selected pixels of said pixel windows surrounding said center pixel for providing an output (47) based on the center deviation σ c , for said center pixel; and a means (22′) connected to said output (47) for obtaining a modification gain, f′(σ c ,C g ) as the modification gain, g; and a means (24′) receiving said center pixel, D c , said annular means, m a , and said modification gain, f′(σ c ,C g ) for providing a modified center pixel, D c ′, in accordance with the following equation: where n is an integer of 0 or more.
Claim 5
Dependent Claim
26 words
A system according with claim 2 or 3 wherein said means (22, 22′) connected to said output (47) is a memory containing modification gain look-up tables.
Claim 6
Dependent Claim
30 words
A system according to claim 2 or 3 wherein said output (47) based on the center deviation is equal to the center deviation divided by the number of selected pixels.
Claim 7
Dependent Claim
37 words
A system according to claim 1, 2 or 3 further including: a background detection circuit portion (110) receiving said annular mean for providing an output that is a measure of the background for said modified center pixel;
Claim 8
Dependent Claim
103 words
means (111) connected to said output of said background detection circuit portion (110) for obtaining a threshold value; and a comparator (112) receiving said threshold value at one input of said comparator and said modified center pixel at a second input of said comparator for which a measure of its background is provided by said background detection circuit, said comparator (112) providing one output signal when said modified center pixel at said second input exceeds or is equal to said threshold value at said one input and providing a different output signal when said modified center pixel is less than said threshold value.
Claim 9
Dependent Claim
103 words
means (111) connected to said output of said background detection circuit portion (110) for obtaining a threshold value; and a comparator (112) receiving said threshold value at one input of said comparator and said modified center pixel at a second input of said comparator for which a measure of its background is provided by said background detection circuit, said comparator (112) providing one output signal when said modified center pixel at said second input exceeds or is equal to said threshold value at said one input and providing a different output signal when said modified center pixel is less than said threshold value.
Claim 10
Dependent Claim
23 words
A system according to claim 5 wherein said means (111) for obtaining a threshold value is a memory containing threshold value look-up tables.
Claim 11
Dependent Claim
101 words
A system according to claim 1 2 or 3 further including: a memory (118) containing look-up tables of half tone values; and a comparator (112) for receiving a half tone value from said memory at one input of said comparator and said modified center pixel at a second input of said comparator, said comparator providing one output signal when said modified center pixel at said input exceeds or is equal to said half tone value at said one input and providing a different output signal when said modified center pixel is less than said half tone value at said one input.
Claim 12
Independent Claim
145 words
A method for modifying pixels that are multiple level signals for a digitized image including the steps of: (a) establishing a moving pixel window from the pixels wherein said pixel window has a center pixel, D c and at least 2 N pixels surrounding said center pixel, where N is an integer of 1 or more; (b) determining the annular mean, m a , of 2 N pixels of said pixels surrounding said center pixel for each established pixel window; (c) establishing a modification gain, g, for each center pixel; and (d) processing the annular mean, m a , the center pixel, D c , and the modification gain, f(σ c ,C g ), to produce a modified center pixel, D c ′, in accordance with the following equation: D c ′ = [g X (D c - m a )] + m a .
Claim 13
Independent Claim
145 words
A method for modifying pixels that are multiple level signals for a digitized image including the steps of: (a) establishing a moving pixel window from the pixels wherein said pixel window has a center pixel, D c and at least 2 N pixels surrounding said center pixel, where N is an integer of 1 or more; (b) determining the annular mean, m a , of 2 N pixels of said pixels surrounding said center pixel for each established pixel window; (c) establishing a modification gain, g, for each center pixel; and (d) processing the annular mean, m a , the center pixel, D c , and the modification gain, f(σ c ,C g ), to produce a modified center pixel, D c ′, in accordance with the following equation: D c ′ = [g X (D c - m a )] + m a .
Claim 14
Dependent Claim
119 words
A method for modifying pixels that are multiple level signals for a digitized image according to claim 9 wherein a step is included determining the center deviation for the center pixel of each established window using selected pixels surrounding the center pixel and wherein the step of providing a modification gain, g, for each center pixel provides a modification gain, f(σ,C g ) for each center pixel that is based on the center deviation which when used in the processing of the last step results in a modified center pixel, D c ′, in accordance with the following equation: D c ′ = [f(σ c ,C g ) x (D c - m a )] + m a .
Claim 15
Dependent Claim
108 words
A method for modifying pixels that are multiple level signals for a digitized image according to claim 9 wherein a step is included determining the center deviation for the center pixel of each established window using selected pixels surrounding the center pixel and wherein the step of providing a modification gain, g, for each center pixel provides a modification gain f′(σ,C g ) for each center pixel that is based on the center deviation which when used in the processing of the last step results in a modified center pixel, D c ′, in accordance with the following equation: where n is an integer of 0 or more.
Claim 16
Dependent Claim
51 words
A method for modifying pixels that are multiple level signals for a digitized image according to claim 10 or 11 wherein the step of establishing the modification gain includes providing a memory containing modification gain look-up tables and using said center deviation for addressing said memory to establish the modification gain.
Claim 17
Dependent Claim
96 words
A method for modifying pixels that are multiple level signals for a digitized image according to claim 10, 11 or 12 including the additional steps of using the annular mean, m a , to provide a measure of the background for said modified center pixel; establishing a threshold value based on the said measure of the background; comparing said threshold value with said modified pixel and providing one signal if said modified pixel is greater or equal to the threshold value and providing a different signal if said modified pixel is less than said threshold value.
Claim 18
Dependent Claim
50 words
A method of modifying pixels that are multiple level signals for a digitized image according to claim 13 wherein the step establishing a threshold value includes providing a memory containing threshold value look-up tables and using said measure of the background for addressing said memory to establish said threshold value.
Claim 19
Dependent Claim
80 words
A method for modifying pixels that are multiple level signals for a digitized image according to claim 9, 10, 11 or 12 including the additional steps of providing a memory containing look-up tables of half tone values; and comparing a half tone value obtained from said memory and providing one signal if said modified pixel is greater or equal to said half tone value and providing a different signal if said modified pixel is less than said half tone value.
References Cited (Backward Citations)
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