US5621824A
Expired / Lapsed
US
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Shading correction method, and apparatus therefor
Assignee: Omron Corp
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Filing: 1991-11-29
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Granted: 1997-04-15
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Expires: 2011-11-29
Abstract
Abstract An image obtained by imaging an object having a solid shape, such as that of a circular column or prism, develops a distribution in brightness since the angle of each portion of the surface of the object with respect to a lighting device and image pick-up device differs depending upon the location. The distribution of brightness is substantially uniform along the longitudinal direction of the object but varies transversely of the object. One line is designated on the captured image of the object in a direction that cuts across the object, and the distribution of brightness on this line is obtained. A two-dimensional shading pattern is obtained by expanding this brightness distribution in the longitudinal direction of the object. The shading pattern represents the distribution of the brightness in the image of the surface of the object. Accordingly, a shading correction is performed by subtracting the shading pattern data from the image data of the object, and the distribution of brightness caused by the solid shape of the object is eliminated.
Inventors
- 👤 Takashi Ijiri
- 👤 Toshihiko Matsumoto
- 👤 Toshimichi Masaki
- 👤 Naoshi Awano
- 👤 Osamu Motooka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:03
CPC Classifications
G; G06; G06T; G06T5/00; G06T15/00; G06T15/50; G06T15/506; G06T15/80
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
150 words
A shading correction method comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a line on said image displayed by said display unit in a direction perpendicular to a longitudinal direction of said object; said designated line being one where there are no images, defects or other noisy images present and where a density level is uniform along said longitudinal direction on said line; extracting the image data along the designated line to form a density level distribution; repeatedly arranging the same said density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions; and performing a shading correction of the image data presenting the object by using said shading-pattern data.
Claim 2
Dependent Claim
150 words
A shading correction method comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a line on said image displayed by said display unit in a direction perpendicular to a longitudinal direction of said object; said designated line being one where there are no images, defects or other noisy images present and where a density level is uniform along said longitudinal direction on said line; extracting the image data along the designated line to form a density level distribution; repeatedly arranging the same said density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions; and performing a shading correction of the image data presenting the object by using said shading-pattern data.
Claim 3
Independent Claim
136 words
A method of creating a shading pattern, comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a line on said image displayed by said display unit in a direction perpendicular to a longitudinal direction of said object; said designated line being one where there are no images, defects or other noisy images present and where a density level is uniform along said longitudinal direction on said line; extracting the image data along the designated line to form a density level distribution; repeatedly arranging the same said density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions.
Claim 4
Independent Claim
136 words
A method of creating a shading pattern, comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a line on said image displayed by said display unit in a direction perpendicular to a longitudinal direction of said object; said designated line being one where there are no images, defects or other noisy images present and where a density level is uniform along said longitudinal direction on said line; extracting the image data along the designated line to form a density level distribution; repeatedly arranging the same said density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions.
Claim 5
Dependent Claim
151 words
A shading correction method comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a plurality of representative points on said image displayed by said display unit; said designated plurality of points being points which have uniform density levels in the vertical direction across the entire length of the object and which are located at portions having images, defects or other noisy images; extracting the image data along the designated points in the horizontal direction to form a density level distribution; repeatedly arranging the same density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions; and performing a shading correction of the image data representing the object by using said shading-pattern data.
Claim 6
Dependent Claim
151 words
A shading correction method comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a plurality of representative points on said image displayed by said display unit; said designated plurality of points being points which have uniform density levels in the vertical direction across the entire length of the object and which are located at portions having images, defects or other noisy images; extracting the image data along the designated points in the horizontal direction to form a density level distribution; repeatedly arranging the same density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions; and performing a shading correction of the image data representing the object by using said shading-pattern data.
Claim 7
Independent Claim
138 words
A method of creating a shading pattern, comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a plurality of representative points on said image displayed by said display unit; said designated plurality of points being points which have uniform density levels in the vertical direction across the entire length of the object and which are located at portions having images, defects or other noisy images; and extracting the image along the designated points in the horizontal direction to form a density level distribution; and repeatedly arranging the same density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions.
Claim 8
Independent Claim
138 words
A method of creating a shading pattern, comprising the steps of: imaging a columnar object using an image pick-up device to obtain image data representing the object; displaying the image represented by said image data on a display unit; designating a plurality of representative points on said image displayed by said display unit; said designated plurality of points being points which have uniform density levels in the vertical direction across the entire length of the object and which are located at portions having images, defects or other noisy images; and extracting the image along the designated points in the horizontal direction to form a density level distribution; and repeatedly arranging the same density level distribution in said longitudinal direction to form shading pattern data representing the distribution of brightness on the surface of the object in two dimensions.
Claim 9
Dependent Claim
24 words
A shading correction method according to claim 1, wherein said sample location is designated by the position of a line drawn on said image.
Claim 10
Dependent Claim
22 words
A shading correction method according to claim 1, wherein said sample location is designated by a slender window displayed on said image.
Claim 11
Dependent Claim
14 words
A shading correction method according to claim 1, wherein an operator performs said designation.
Claim 12
Dependent Claim
17 words
A method of creating a shading pattern according to claim 2, wherein an operator performs said designation.
Claim 13
Dependent Claim
14 words
A shading correction method according to claim 3, wherein an operator performs said designation.
Claim 14
Dependent Claim
17 words
A method of creating a shading pattern according to claim 4, wherein an operator performs said designation.
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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) | 2000-04-14 | 2000-10-14 | 2001-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-14 | 2004-10-14 | 2005-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-14 | 2008-10-14 | 2009-04-15 | $7700.00 | Window Closed / Lapsed |