US6697535B1
Expired / Lapsed
US
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Method for refining a parameter of a contour in an image
Assignee: Cognex Technology and Investment LLC
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Filing: 1999-11-24
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Granted: 2004-02-24
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Expires: 2019-11-24
Abstract
Abstract Methods and apparatuses are disclosed for refining groupings of edge points that represent contours in an image. The methods and apparatuses decrease data dispersion and data quantization effects. The methods and apparatuses are particularly useful for accurate and robust detection of straight line-segment features contained in noisy, cluttered imagery occurring in industrial machine vision applications. Additionally, a measurement criterion of the quality of the detected line segments is introduced.
Inventors
- 👤 Paul Dutta-Choudhury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:03
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/40; G06V10/48
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
204 words
A method for refining at least one contour parameter of a contour in an image, the method comprising: detecting edge points in the image; calculating a plurality of contour parameters for each of the edge points; filling a first parameter space with the plurality of contour parameters of the edge points, the first parameter space defined by a plurality of parameter axes having first bins, where each of the plurality of parameter axes represents one of the plurality of contour parameters, and where each non-null bin of the first parameter space represents a contour; filling a second parameter space with the plurality of contour parameters of edge points, the second parameter space defined by a plurality of parameter axes having second bins, where each of the plurality of parameter axes represents one of the plurality of contour parameters, and where each non-null bin of the second parameter space represents a contour, the second parameter space being fractionally offset from the first parameter space along at least one of the plurality of parameter axes; and merging the second parameter space and the first parameter space to create a hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space.
Claim 2
Independent Claim
204 words
A method for refining at least one contour parameter of a contour in an image, the method comprising: detecting edge points in the image; calculating a plurality of contour parameters for each of the edge points; filling a first parameter space with the plurality of contour parameters of the edge points, the first parameter space defined by a plurality of parameter axes having first bins, where each of the plurality of parameter axes represents one of the plurality of contour parameters, and where each non-null bin of the first parameter space represents a contour; filling a second parameter space with the plurality of contour parameters of edge points, the second parameter space defined by a plurality of parameter axes having second bins, where each of the plurality of parameter axes represents one of the plurality of contour parameters, and where each non-null bin of the second parameter space represents a contour, the second parameter space being fractionally offset from the first parameter space along at least one of the plurality of parameter axes; and merging the second parameter space and the first parameter space to create a hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space.
Claim 3
Dependent Claim
38 words
The method of claim 1 , wherein the contour is a line, the first parameter space and the second parameter space are Hough-line spaces, and the plurality of parameter axes include a distance-vector axis and a line-angle axis.
Claim 4
Dependent Claim
14 words
The method of claim 2 , wherein the offset is along the line-angle axis.
Claim 5
Dependent Claim
39 words
The method of claim 1 , wherein the edge points have features and wherein calculating the plurality of contour parameters of the edge points further includes: calculating the plurality of contour parameters of the edge points using the features.
Claim 6
Dependent Claim
132 words
The method of claim 1 , wherein each of the first bins and the second bins has a weight equal to a number of the edge points in each of the first bins and the second bins, respectively, and wherein the merging further includes: comparing the weight of the first bins of the first parameter space to the weight of the second bins of the second parameter space for each of the respective edge points to determine a greater-weight bin for each of the respective edge points; determining hybrid bins in both the first parameter space and the second parameter space having more than half of the edge points of each of the first bins and second bins being the greater-weight bin; and creating the hybrid-parameter space composed of the hybrid bins.
Claim 7
Dependent Claim
32 words
The method of claim 1 , wherein the hybrid-parameter space includes some of the first bins from the first parameter space and some of the second bins from the second parameter space.
Claim 8
Dependent Claim
55 words
The method of claim 1 , wherein the merging further includes: merging a subset of the second bins from the second parameter space and a subset of the first bins from the first parameter space to create the hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space.
Claim 9
Dependent Claim
27 words
The method of claim 1 , further comprising: filtering the edge points by peak detection before filling the first parameter space and the filling second parameter space.
Claim 10
Independent Claim
269 words
An apparatus for refining a contour parameter of a contour from an image, the apparatus comprising: an image having edge points, calculation means adapted to calculate a plurality of contour parameters for each of the edge points; a first parameter space, defined by a plurality of parameter axes, where each of the plurality of parameter axes represents one of the plurality of contour parameters, each of the parameter axes having first bins, the first bins being adapted to receive the edge points by the plurality of contour parameters, where each non-null first bin of the parameter space represents a contour; a second parameter space, defined by a plurality of parameter axes, where each of the plurality of parameter axes represents one of the plurality of contour parameters, each of the parameter axes having second bins, the second bins being adapted to receive the edge points by the plurality of contour parameters, where each non-null second bin of the second parameter space represents a contour, the second parameter space being fractionally offset from the first parameter space along one of the plurality of parameter axes; filling means, in communication with the calculation means, adapted to fill the first parameter space and the second parameter space according to the plurality of contour parameters of the edge points; a hybrid-parameter space adapted to receive a sub-set of the first bins and a sub-set of the second bins; and merging means, adapted to merge the second parameter space and the first parameter space to create the hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space.
Claim 11
Independent Claim
269 words
An apparatus for refining a contour parameter of a contour from an image, the apparatus comprising: an image having edge points, calculation means adapted to calculate a plurality of contour parameters for each of the edge points; a first parameter space, defined by a plurality of parameter axes, where each of the plurality of parameter axes represents one of the plurality of contour parameters, each of the parameter axes having first bins, the first bins being adapted to receive the edge points by the plurality of contour parameters, where each non-null first bin of the parameter space represents a contour; a second parameter space, defined by a plurality of parameter axes, where each of the plurality of parameter axes represents one of the plurality of contour parameters, each of the parameter axes having second bins, the second bins being adapted to receive the edge points by the plurality of contour parameters, where each non-null second bin of the second parameter space represents a contour, the second parameter space being fractionally offset from the first parameter space along one of the plurality of parameter axes; filling means, in communication with the calculation means, adapted to fill the first parameter space and the second parameter space according to the plurality of contour parameters of the edge points; a hybrid-parameter space adapted to receive a sub-set of the first bins and a sub-set of the second bins; and merging means, adapted to merge the second parameter space and the first parameter space to create the hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space.
Claim 12
Dependent Claim
32 words
The apparatus of claim 9 , wherein the contour is a line, the parameter spaces are Hough-line spaces, and the plurality of parameter axes are a distance-vector axis and a line-angle axis.
Claim 13
Dependent Claim
14 words
The apparatus of claim 10 , wherein the offset is along the line-angle axis.
Claim 14
Dependent Claim
33 words
The apparatus of claim 9 , wherein the edge points have features and wherein the calculation means is adapted to calculated the plurality of contour parameters of the edge points using the features.
Claim 15
Dependent Claim
34 words
The apparatus of claim 9 , wherein the hybrid space includes a subset of the second bins from the second parameter space and a subset of the first bins from the first parameter space.
Claim 16
Independent Claim
291 words
A method for refining at least one contour parameter of a contour comprised of edge points, the edge points having features, the method comprising: calculating a plurality of contour parameters for each of the edge points using at least a portion of the features; generating a first parameter space defined by a plurality of first parameter axes, where each of the plurality of first parameter axes represents one of the plurality of contour parameters, each of the plurality of first parameter axis divided into a first set of discrete bins, the bins adapted to receive edge points according to the plurality of contour parameters of each of the edge points; generating a second parameter space defined by a plurality of second parameter axes, where each of the plurality of second parameter axes represents one of the plurality of contour parameters, each of the plurality of second parameter axis divided into a second set of discrete bins; the bins adapted to receive edge points according to the plurality of contour parameters of each of the edge points, the second parameter space being fractionally offset from the first parameter space along at least one of the plurality of parameter axes; assigning the edge points to one of the bins in each of the first parameter space and the second parameter space according to the plurality of contour parameters of each of the edge points, where each non-null bin of the first parameter space and the second parameter space represents a contour; and merging the second parameter space and the first parameter space to create one hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space, thereby refining the at least one contour parameter of a contour.
Claim 17
Independent Claim
291 words
A method for refining at least one contour parameter of a contour comprised of edge points, the edge points having features, the method comprising: calculating a plurality of contour parameters for each of the edge points using at least a portion of the features; generating a first parameter space defined by a plurality of first parameter axes, where each of the plurality of first parameter axes represents one of the plurality of contour parameters, each of the plurality of first parameter axis divided into a first set of discrete bins, the bins adapted to receive edge points according to the plurality of contour parameters of each of the edge points; generating a second parameter space defined by a plurality of second parameter axes, where each of the plurality of second parameter axes represents one of the plurality of contour parameters, each of the plurality of second parameter axis divided into a second set of discrete bins; the bins adapted to receive edge points according to the plurality of contour parameters of each of the edge points, the second parameter space being fractionally offset from the first parameter space along at least one of the plurality of parameter axes; assigning the edge points to one of the bins in each of the first parameter space and the second parameter space according to the plurality of contour parameters of each of the edge points, where each non-null bin of the first parameter space and the second parameter space represents a contour; and merging the second parameter space and the first parameter space to create one hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space, thereby refining the at least one contour parameter of a contour.
Claim 18
Dependent Claim
32 words
The method of claim 14 , wherein the contour is a line, the parameter spaces are Hough-line spaces, and the plurality of parameter axes are a distance-vector axis and a line-angle axis.
Claim 19
Dependent Claim
14 words
The method of claim 15 , wherein the offset is along the line-angle axis.
Claim 20
Dependent Claim
26 words
The method of claim 14 , wherein the hybrid-parameter space includes some of the bins from both the first parameter space and the second parameter space.
Claim 21
Dependent Claim
30 words
The method of claim 14 , further comprising: filtering the edge points by peak detection before assigning the edge points to the first parameter space and the second parameter space.
Claim 22
Dependent Claim
55 words
The method of claim 14 , wherein the merging further includes: merging a subset of the second bins from the second parameter space and a subset of the first bins from the first parameter space to create the hybrid-parameter space such that each of the edge points is substantially represented once in the hybrid-parameter space.
References Cited (Backward Citations)
US3069654A
Cited
US4644583A
Cited
US4731858A
Cited
US5081689A
Cited
US5162994A
Cited
US5220621A
Cited
US5412742A
Cited
US5615319A
Cited
US5422962A
Cited
US5657403A
Cited
US5339367A
Cited
US5418892A
Cited
US6259809B1
Cited
US5960371A
Cited
US6222993B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-02-23 | 2007-08-25 | 2008-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-02-23 | 2011-08-25 | 2012-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-02-23 | 2015-08-25 | 2016-02-24 | $7700.00 | Window Closed / Lapsed |