US6915008B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for multi-nodal, three-dimensional imaging
Assignee: Teledyne Flir Commercial Systems Inc
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Filing: 2002-03-08
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Granted: 2005-07-05
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Expires: 2022-03-08
Abstract
Abstract A system for localizing objects has two or more measurement units. Calibration methods provide transformations to a common reference frame by locating calibration features in local reference frames of the measurement units. A calibration target spanning measurement fields of the measurement units may be used. The measurement units may have overlapping measurement fields. The measurement units may comprise stereo vision units or other units capable of locating objects or object features.
Inventors
- 👤 Rod Barman
- 👤 Malcolm Steenburgh
- 👤 Don Murray
- 👤 Shyan Ku
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:17
CPC Classifications
G; G01; G01B; G01B11/00; G06; G06T; G06T7/00; G06T7/80; G06T7/85; H; H04; H04N; H04N13/00; H04N13/20; H04N13/204; H04N13/239; H04N13/243; H04N13/246; G06T2207/00; G06T2207/10; G06T2207/10004; G06T2207/10012; H04N2013/0074; H04N2013/0081
Claims Analysis
Total Claims: 67
Claim 1
Independent Claim
169 words
A method for calibrating a three-dimensional imaging system the method comprising: providing first and second measurement units, the first measurement unit configured to acquire information from which locations of object features within a first measurement field can be determined in a first local coordinate system, the second measurement unit configured to acquire information from which locations of object features within a second measurement field can be determined in a second local coordinate system; determining first locations in the first local coordinate system of a first plurality of calibration features located in the first measurement field, and, based on the first locations, determining locations in the first local coordinate system of a second plurality of calibration features located in the second measurement field; determining locations of the second plurality of features in the second local coordinate system; and, deriving a transformation between the local coordinate systems and a common coordinate system based upon the locations of the second plurality of calibration features in the first and second local coordinate systems.
Claim 2
Independent Claim
169 words
A method for calibrating a three-dimensional imaging system the method comprising: providing first and second measurement units, the first measurement unit configured to acquire information from which locations of object features within a first measurement field can be determined in a first local coordinate system, the second measurement unit configured to acquire information from which locations of object features within a second measurement field can be determined in a second local coordinate system; determining first locations in the first local coordinate system of a first plurality of calibration features located in the first measurement field, and, based on the first locations, determining locations in the first local coordinate system of a second plurality of calibration features located in the second measurement field; determining locations of the second plurality of features in the second local coordinate system; and, deriving a transformation between the local coordinate systems and a common coordinate system based upon the locations of the second plurality of calibration features in the first and second local coordinate systems.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein the first and second measurement fields overlap within an overlap region and the first and second pluralities of calibration features are located within the overlap region.
Claim 4
Dependent Claim
20 words
The method of claim 2 wherein the first and second pluralities of calibration features each comprise the same calibration features.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein the first and second pluralities of calibration features are rigidly connected to one another.
Claim 6
Dependent Claim
58 words
The method of claim 1 wherein determining the locations in the first local coordinate system of the second plurality of calibration features comprises determining locations of each of the first and second pluralities of calibration features relative to one another using one or more additional measurement units having measurement fields overlapping with the first and second measurement fields.
Claim 7
Independent Claim
118 words
A method for calibrating a three-dimensional imaging system the method comprising: providing first and second measurement units, the first measurement unit configured to determine locations of object features within a first measurement field in a first local coordinate system, the second measurement unit configured to determine locations of object features within a second measurement field in a second local coordinate system, the first and second measurement fields overlapping within an overlap region; determining locations of a plurality of calibration features located in the overlap region in each of the first and second local coordinate systems; deriving a transformation between the local coordinate systems and a common coordinate system based upon the locations of the plurality of calibration features.
Claim 8
Independent Claim
118 words
A method for calibrating a three-dimensional imaging system the method comprising: providing first and second measurement units, the first measurement unit configured to determine locations of object features within a first measurement field in a first local coordinate system, the second measurement unit configured to determine locations of object features within a second measurement field in a second local coordinate system, the first and second measurement fields overlapping within an overlap region; determining locations of a plurality of calibration features located in the overlap region in each of the first and second local coordinate systems; deriving a transformation between the local coordinate systems and a common coordinate system based upon the locations of the plurality of calibration features.
Claim 9
Dependent Claim
23 words
The method of claim 6 wherein the common coordinate system is the same as one of the first and second local coordinate systems.
Claim 10
Dependent Claim
25 words
The method of claim 6 wherein deriving a transformation between the local coordinate systems and a common coordinate system to comprises performing an iterative process.
Claim 11
Dependent Claim
49 words
The method of claim 8 wherein the iterative process comprises: obtaining an estimated transformation, applying the estimated transformation to the locations of the plurality of calibration features, determining an error in the estimated transformation, determining a correction based on the error, and applying the correction to the estimated transformation.
Claim 12
Dependent Claim
16 words
The method of claim 9 wherein the iterative process comprises performing steps in a least-squares algorithm.
Claim 13
Dependent Claim
17 words
The method of claim 9 wherein the iterative process comprises applying different weightings to different calibration features.
Claim 14
Dependent Claim
50 words
The method of claim 8 wherein the iterative process comprises: obtaining an estimated transformation; correcting the estimated transformation; identifying one or more redundant calibration features for which the estimated trasformations produces statistically outlying results; and, correcting the estimated transformation again without reference to the one or more redundant calibration features.
Claim 15
Dependent Claim
101 words
The method of claim 6 comprising: providing an additional measurement unit having a measurement field overlapping with one of the first and second measurement fields in an additional overlap region, the additional measurement unit configured to determine locations of object features within its measurement field in an additional local coordinate system; determining locations of a plurality of calibration features located in the additional overlap region in the additional local coordinate system; deriving a transformation between the additional local coordinate system and a common coordinate system based upon the locations of the plurality of calibration features located in the additional overlap region.
Claim 16
Dependent Claim
27 words
The method of claim 6 wherein determining locations of a plurality of calibration features comprises determining locations of a plurality of features of a known calibration object.
Claim 17
Dependent Claim
63 words
The method of claim 6 wherein determining locations of a plurality of calibration features comprises: determining a location of a calibration feature on a calibration object; moving the calibration object; determining a new location of the calibration feature; and, repeating moving the calibration object and determining a new location of the calibration feature until a desired number of new locations has been determined.
Claim 18
Dependent Claim
55 words
The method of claim 6 comprising determining in the common coordinate system a location of a first object feature located in the first measurement field and not located in the second measurement field and a location of a second object feature located in the second measurement field and not located in the first measurement field.
Claim 19
Dependent Claim
20 words
The method of claim 6 wherein the calibration features comprise a feature of a calibration target comprising a spherical object.
Claim 20
Dependent Claim
29 words
The method of claim 17 wherein determining locations of a plurality of calibration features comprises performing a circular Hough transform on image data from a plurality of imaging devices.
Claim 21
Dependent Claim
17 words
The method of claim 6 wherein the calibration features comprise a feature of a planar calibration target.
Claim 22
Dependent Claim
18 words
The method of claim 19 wherein the planar calibration target comprises a circular figure on a contrasting background.
Claim 23
Dependent Claim
29 words
The method of claim 20 wherein determining locations of a plurality of calibration features comprises performing a circular Hough transform on image data from a plurality of imaging devices.
Claim 24
Independent Claim
195 words
A method for calibrating a three-dimensional imaging system the method comprising: obtaining image data from a plurality of imaging devices of a first stereo measurement unit, the imaging devices having fields of view that overlap in a first stereo measurement field; obtaining image data from a plurality of imaging devices of a second stereo measurement unit, the imaging devices having fields of view that overlap in a second stereo measurement field, the first and second stereo measurement fields overlapping one another in an overlap region containing at least one calibration target; determining three-dimensional characteristics of at least one calibration target relative to the first stereo measurement unit using image data obtained from the imaging devices of the first stereo measurement unit; determining three-dimensional characteristics of at least one calibration target relative to the second stereo measurement unit using image data obtained from the imaging devices of the second stereo measurement unit; and, deriving calibration parameters from the three-dimensional characteristics of the calibration targets relative to the first and second stereo measurement units, the calibration parameters comprising information about a position and orientation of the first stereo measurement units relative to the second stereo measurement unit.
Claim 25
Independent Claim
195 words
A method for calibrating a three-dimensional imaging system the method comprising: obtaining image data from a plurality of imaging devices of a first stereo measurement unit, the imaging devices having fields of view that overlap in a first stereo measurement field; obtaining image data from a plurality of imaging devices of a second stereo measurement unit, the imaging devices having fields of view that overlap in a second stereo measurement field, the first and second stereo measurement fields overlapping one another in an overlap region containing at least one calibration target; determining three-dimensional characteristics of at least one calibration target relative to the first stereo measurement unit using image data obtained from the imaging devices of the first stereo measurement unit; determining three-dimensional characteristics of at least one calibration target relative to the second stereo measurement unit using image data obtained from the imaging devices of the second stereo measurement unit; and, deriving calibration parameters from the three-dimensional characteristics of the calibration targets relative to the first and second stereo measurement units, the calibration parameters comprising information about a position and orientation of the first stereo measurement units relative to the second stereo measurement unit.
Claim 26
Dependent Claim
37 words
A method according to claim 22 comprising deriving transformation functions based on the calibration parameters, the transformation functions providing a relationship between position data obtained from a pair of the imaging devices and a common coordinate system.
Claim 27
Dependent Claim
28 words
A method according to claim 23 , wherein determining the three-dimensional characteristics of at least one calibration target comprises determining three-dimensional characteristics of a plurality of calibration features.
Claim 28
Dependent Claim
36 words
A method according to claim 23 , wherein determining the three-dimensional characteristics of at least one calibration target comprises determining three-dimensional characteristics of at least one of: circles, spheres, lines, and corners of a calibration object.
Claim 29
Dependent Claim
65 words
A method according to claim 23 , comprising measuring three-dimensional characteristics of an object located in any of the first stereo measurement field and the second stereo measurement field using the calibration parameters and using image data obtained from at least two imaging devices selected from: the imaging devices of the first stereo measurement unit and the imaging devices of the second stereo measurement unit.
Claim 30
Dependent Claim
114 words
A method according to claim 23 , comprising: obtaining image data from a plurality of imaging devices of each of one or more additional stereo measurement units, the imaging devices of each additional stereo measurement unit having fields of view that overlap one another in additional stereo measurement fields, at least one of the additional stereo measurement fields connected to at least one of the first and second stereo measurement fields by overlapping regions; and, deriving, from the image data obtained from the plurality of imaging devices of the additional stereo measurement units, calibration parameters comprising information about a position and orientation of each additional stereo measurement unit relative to a common coordinate system.
Claim 31
Dependent Claim
52 words
A method according to claim 24 , wherein deriving each transformation function comprises starting with an estimated transformation function and then iteratively optimizing the transformation function to reduce differences between the three-dimensional characteristics of calibration targets in transformed image data and three-dimensional characteristics of the calibration targets in the common coordinate system.
Claim 32
Dependent Claim
26 words
A method according to claim 28 , wherein optimizing the transformation function comprises selectively weighing three-dimensional characteristics of some of the one or more calibration targets.
Claim 33
Dependent Claim
186 words
Apparatus for determining the locations of object features in three dimensions, the apparatus comprising: a first measurement unit configured to generate first data from which locations of object features in a first measurement field can be determined in a first local coordinate system; a second measurement unit configured to generate second data from which locations of object features in a second measurement field can be determined in a second local coordinate system; and, a processor configured to: receive the first and second data; extract from the first data information about a first plurality of calibration features in the first measurement field; and, based on the calibration information, determine locations in the first local coordinate system of a second plurality of calibration features in the second measurement field; determine from the second data locations of the second plurality of calibration features in the second local coordinate system; and, based on the locations of the second plurality of calibration features in the first and second local coordinate systems, generate a transformation which, when applied to the second data, expresses locations of object features in a common coordinate system.
Claim 34
Dependent Claim
186 words
Apparatus for determining the locations of object features in three dimensions, the apparatus comprising: a first measurement unit configured to generate first data from which locations of object features in a first measurement field can be determined in a first local coordinate system; a second measurement unit configured to generate second data from which locations of object features in a second measurement field can be determined in a second local coordinate system; and, a processor configured to: receive the first and second data; extract from the first data information about a first plurality of calibration features in the first measurement field; and, based on the calibration information, determine locations in the first local coordinate system of a second plurality of calibration features in the second measurement field; determine from the second data locations of the second plurality of calibration features in the second local coordinate system; and, based on the locations of the second plurality of calibration features in the first and second local coordinate systems, generate a transformation which, when applied to the second data, expresses locations of object features in a common coordinate system.
Claim 35
Dependent Claim
29 words
The apparatus of claim 30 wherein the first and second measurement fields overlap in an overlap region and the second plurality of calibration features is in the overlap region.
Claim 36
Dependent Claim
20 words
The apparatus of claim 30 wherein the first and second pluralities of calibration features each comprise the same calibration features.
Claim 37
Dependent Claim
155 words
Apparatus for determining the locations of object features in three dimensions, the apparatus comprising: a first measurement unit configured to generate first data from which locations of object features in a first measurement field can be determined in a first local coordinate system; a second measurement unit configured to generate second data from which locations of object features in a second measurement field can be determined in a second local coordinate system, the second measurement unit located so that the first and second measurement fields overlap in an overlap region; and, a processor configured to: receive the first and second data; extract from each of the first and second data calibration information about a plurality of calibration features of one or more calibration objects located in the overlap region; and, based on the calibration information, generate a transformation which, when applied to the second data expresses locations of object features in a common coordinate system.
Claim 38
Dependent Claim
155 words
Apparatus for determining the locations of object features in three dimensions, the apparatus comprising: a first measurement unit configured to generate first data from which locations of object features in a first measurement field can be determined in a first local coordinate system; a second measurement unit configured to generate second data from which locations of object features in a second measurement field can be determined in a second local coordinate system, the second measurement unit located so that the first and second measurement fields overlap in an overlap region; and, a processor configured to: receive the first and second data; extract from each of the first and second data calibration information about a plurality of calibration features of one or more calibration objects located in the overlap region; and, based on the calibration information, generate a transformation which, when applied to the second data expresses locations of object features in a common coordinate system.
Claim 39
Dependent Claim
18 words
The apparatus of claim 33 wherein the first and second measurement fields have substantially parallel axes of symmetry.
Claim 40
Dependent Claim
18 words
The apparatus of claim 33 wherein the first and second measurement fields cross one another at an angle.
Claim 41
Dependent Claim
42 words
The apparatus of claim 33 wherein each of the measurement units comprises two or more spaced-apart imaging devices and the imaging devices of each of the measurement units have fields of view which overlap with one another in the corresponding measurement field.
Claim 42
Dependent Claim
31 words
The apparatus of claim 36 wherein each of the imaging devices has an optical axis and the optical axes of the plurality of imaging devices are substantially parallel to one another.
Claim 43
Dependent Claim
22 words
The apparatus of claim 33 wherein the processor is configured to perform a model-based recognition algorithm on the first and second data.
Claim 44
Dependent Claim
29 words
The apparatus of claim 33 wherein the processor is configured to perform a circular Hough transform on the first and second data to locate features of circular calibration targets.
Claim 45
Dependent Claim
45 words
The apparatus of claim 33 comprising a plurality of additional measurement units having corresponding additional measurement fields each connected to at least one of: the first measurement field, the second measurement field and another additional measurement field, by way of one or more overlapping regions.
Claim 46
Dependent Claim
169 words
Apparatus for determining the locations of object features in three dimensions, the apparatus comprising: a first stereo measurement unit comprising a plurality of imaging devices, the imaging devices having fields of view that overlap in a first stereo measurement field; a second stereo measurement unit comprising a plurality of imaging devices, the imaging devices having fields of view that overlap in a second stereo measurement field, the first and second stereo measurement fields overlapping one another in an overlap region; and, a processor, configured to: receive image data from individual imaging devices in the fist and second stereo measurement units; derive calibration parameters related to relative positions and orientations of the first and second stereo measurement units, such that image data received from the first and second stereo vision units may be transformed to a common reference coordinate system, using the calibration parameters, and, locate features of objects in the first or second stereo measurement field in a common coordinate system using the image data and the calibration parameters.
Claim 47
Dependent Claim
169 words
Apparatus for determining the locations of object features in three dimensions, the apparatus comprising: a first stereo measurement unit comprising a plurality of imaging devices, the imaging devices having fields of view that overlap in a first stereo measurement field; a second stereo measurement unit comprising a plurality of imaging devices, the imaging devices having fields of view that overlap in a second stereo measurement field, the first and second stereo measurement fields overlapping one another in an overlap region; and, a processor, configured to: receive image data from individual imaging devices in the fist and second stereo measurement units; derive calibration parameters related to relative positions and orientations of the first and second stereo measurement units, such that image data received from the first and second stereo vision units may be transformed to a common reference coordinate system, using the calibration parameters, and, locate features of objects in the first or second stereo measurement field in a common coordinate system using the image data and the calibration parameters.
Claim 48
Dependent Claim
26 words
An apparatus according to claim 41 , wherein the imaging devices comprise at least one of: digital cameras, analog cameras, acoustic sensors and laser range finders.
Claim 49
Dependent Claim
84 words
An apparatus according to claim 41 , wherein the processor is one of: a computer executing a program; an embedded processor that is part of at least one of the first and second stereo measurement units and that is configured to execute instructions contained in memory accessible to the embedded processor; and a detachable processor that is attachable to, and detachable from, the first and second stereo measurement units and that is configured to execute instructions contained in memory accessible to the detachable processor.
Claim 50
Independent Claim
139 words
An apparatus for determining locations of object features, the apparatus comprising: means for obtaining first data representing locations of object features in a first measurement field in a first local coordinate system; means for obtaining second data representing locations of object features in a second measurement field in a second local coordinate system; means for locating in the first data a first plurality of calibration features in the first measurement field and determining based on the first plurality of calibration features, locations of a second plurality of calibration features in the second measurement field; means for locating in the second data the plurality of calibration features; means for determining calibration parameters based on the calibration features located in the first and second data; and, means for locating object features relative to a common coordinate system using the calibration parameters.
Claim 51
Independent Claim
139 words
An apparatus for determining locations of object features, the apparatus comprising: means for obtaining first data representing locations of object features in a first measurement field in a first local coordinate system; means for obtaining second data representing locations of object features in a second measurement field in a second local coordinate system; means for locating in the first data a first plurality of calibration features in the first measurement field and determining based on the first plurality of calibration features, locations of a second plurality of calibration features in the second measurement field; means for locating in the second data the plurality of calibration features; means for determining calibration parameters based on the calibration features located in the first and second data; and, means for locating object features relative to a common coordinate system using the calibration parameters.
Claim 52
Dependent Claim
17 words
The apparatus of claim 44 wherein the first and second measurement fields overlap in an overlap region.
Claim 53
Dependent Claim
28 words
The apparatus of claim 44 wherein the means for determining calibration parameters comprises a means for deriving one or more transformation functions from the first and second data.
Claim 54
Independent Claim
47 words
The apparatus of clam 45 wherein the transformation functions are adapted to provide as outputs the locations of object features in a common coordinate system when the transformation functions are used in processing the first data or the second data or both the first and second data.
Claim 55
Independent Claim
47 words
The apparatus of clam 45 wherein the transformation functions are adapted to provide as outputs the locations of object features in a common coordinate system when the transformation functions are used in processing the first data or the second data or both the first and second data.
Claim 56
Dependent Claim
50 words
An apparatus according to claim 46 wherein the first data comprises image data from two or more imaging devices and the apparatus comprises means for locating object features in the image data from each of two or more imaging devices and determining a position of the object features by triangulation.
Claim 57
Dependent Claim
29 words
An apparatus according to claim 44 wherein the first and second data respectively comprise coordinates in the first and second local coordinate systems of points in a point cloud.
Claim 58
Dependent Claim
143 words
Processing apparatus for use in determining locations of object features detected by one of a plurality of measurement in units, the processing apparatus comprising: an input for receiving first data from which locations of object features in a first measurement field can be determined in a first local coordinate system and second data from which locations of object features in a second measurement field can be determined in a second local coordinate system, the first and second measurement fields overlapping in an overlap region; and, a processor configured to: extract from each of the first and second data calibration information about a plurality of calibration features of one or more calibration objects located in the overlap region; and, based on the calibration information, generate a transformation which, when applied to the second data expresses locations of object features in a common coordinate system.
Claim 59
Dependent Claim
143 words
Processing apparatus for use in determining locations of object features detected by one of a plurality of measurement in units, the processing apparatus comprising: an input for receiving first data from which locations of object features in a first measurement field can be determined in a first local coordinate system and second data from which locations of object features in a second measurement field can be determined in a second local coordinate system, the first and second measurement fields overlapping in an overlap region; and, a processor configured to: extract from each of the first and second data calibration information about a plurality of calibration features of one or more calibration objects located in the overlap region; and, based on the calibration information, generate a transformation which, when applied to the second data expresses locations of object features in a common coordinate system.
Claim 60
Dependent Claim
155 words
A machine readable medium carrying a set of instructions which, when executed by a data processor cause the data processor to perform a method for calibrating a three-dimensional imaging system, comprising; receiving first image data from a plurality of first imaging devices of a first measurement unit, the first imaging devices having fields of view that overlap in a first measurement field and second image data from a plurality of second imaging devices of a second measurement unit, the second imaging devices having fields of view that overlap in a second measurement field, the first and second stereo measurement fields overlapping one another in an overlap region; locating a plurality of calibration features in each of the first and second image data; determining, from the locations in the first and second data of the calibration features, information characterizing a position and orientation of the second stereo measurement unit relative to the first stereo measurement unit.
Claim 61
Dependent Claim
155 words
A machine readable medium carrying a set of instructions which, when executed by a data processor cause the data processor to perform a method for calibrating a three-dimensional imaging system, comprising; receiving first image data from a plurality of first imaging devices of a first measurement unit, the first imaging devices having fields of view that overlap in a first measurement field and second image data from a plurality of second imaging devices of a second measurement unit, the second imaging devices having fields of view that overlap in a second measurement field, the first and second stereo measurement fields overlapping one another in an overlap region; locating a plurality of calibration features in each of the first and second image data; determining, from the locations in the first and second data of the calibration features, information characterizing a position and orientation of the second stereo measurement unit relative to the first stereo measurement unit.
Claim 62
Independent Claim
125 words
A method of calibrating a three-dimensional imaging system comprising a plurality of measurement units each having a local coordinate system, the method comprising: a step for acquiring locations of a plurality of calibration features in a first local coordinate system of a first measurement unit; a step for acquiring locations of the plurality of calibration features in each of one or more additional local coordinate systems; and, a step for creating a transformation from one or more of the local coordinate systems to a common coordinate system based on the locations of the plurality of calibration features in the first local coordinate system and the locations of the plurality of calibration features in at least one of the one or more additional local coordinate systems.
Claim 63
Independent Claim
125 words
A method of calibrating a three-dimensional imaging system comprising a plurality of measurement units each having a local coordinate system, the method comprising: a step for acquiring locations of a plurality of calibration features in a first local coordinate system of a first measurement unit; a step for acquiring locations of the plurality of calibration features in each of one or more additional local coordinate systems; and, a step for creating a transformation from one or more of the local coordinate systems to a common coordinate system based on the locations of the plurality of calibration features in the first local coordinate system and the locations of the plurality of calibration features in at least one of the one or more additional local coordinate systems.
Claim 64
Independent Claim
155 words
A method for calibrating a three-dimensional imaging system comprising: providing first and second measurement units, the first measurement unit configured to determine locations in a first local coordinate system of object features within a first measurement field, the second measurement unit configured to determine in a second local coordinate system locations of object features within a second measurement field; determining locations of a first plurality of calibration features in the first local coordinate system, the first plurality of calibration features located in the first measurement field; determining locations of a second plurality of calibration features in the second local coordinate system the second plurality of calibration features located in the second measurement field, first plurality of features having a fixed location relative to the second plurality of features; and, deriving a transformation between the local coordinate systems and a common coordinate system based upon the locations of the first and second pluralities of calibration features.
Claim 65
Independent Claim
155 words
A method for calibrating a three-dimensional imaging system comprising: providing first and second measurement units, the first measurement unit configured to determine locations in a first local coordinate system of object features within a first measurement field, the second measurement unit configured to determine in a second local coordinate system locations of object features within a second measurement field; determining locations of a first plurality of calibration features in the first local coordinate system, the first plurality of calibration features located in the first measurement field; determining locations of a second plurality of calibration features in the second local coordinate system the second plurality of calibration features located in the second measurement field, first plurality of features having a fixed location relative to the second plurality of features; and, deriving a transformation between the local coordinate systems and a common coordinate system based upon the locations of the first and second pluralities of calibration features.
Claim 66
Dependent Claim
34 words
A method according to claim 53 , wherein said first and second stereo measurement fields overlap within an overlap region and the first and second pluralities of features are located in the overlap region.
Claim 67
Dependent Claim
40 words
A method according to claim 54 , wherein determining locations of a first plurality of calibration features in the first local coordinate system also determines the locations of the second plurality of calibration features in the first local coordinate system.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 2008-07-04 | 2009-01-03 | 2009-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-07-04 | 2013-01-03 | 2013-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-07-04 | 2017-01-03 | 2017-07-05 | $7700.00 | Window Closed / Lapsed |