US4873651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for reconstructing three-dimensional surfaces from two-dimensional images
Assignee: Case Western Reserve University
•
Filing: 1987-04-21
•
Granted: 1989-10-10
•
Expires: 2007-04-21
Abstract
Abstract A method and apparatus for reconstructing the surface, i.e the third dimension, of a three-dimensional object from two-dimemsional information includes projecting radiant energy, such as light, from a substantially parallel ray source at said object at a number of different angles relative to a reference surface with respect to which the object is placed. The lengths and locations of shadows cast by the object are measured as a function of the angle of the light rays. The location of the surface of the object relative to the reference surface is determined from the shadow lengths and locations from the angles at which the respective shadow lengths are created. Preferably, the shadow lengths and locations are measured by an electronic camera that generates electrical signals indicative of the shadow image. These signals are preferably received by a computer that determines the location of the surface of the object relative to the reference surface. Preferably, the computer also controls the position of the energy source. The method is relatively insensitive to variations in measurement and signal processing conditions. The position information produced in applying the method may be used in many applications, for example, for positioning a robot gripper to retrieve a part from a bin.
Inventors
- 👤 Daniel Raviv
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:20
CPC Classifications
G; G06; G06T; G06T1/00; G06T1/0014
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
127 words
A method of reconstructing the third dimension of an object comprising: disposing said object in a fixed position relative to a reference surface; projecting substantially parallel rays of radiant energy at said object at a plurality of different angles relative to said reference surface; recording the relative locations and lengths of each of the shadows cast by the object at each of said angles, said shadows including portions thereof formed on the reference surface; and determining from the length and relative location of each of said shadows cast and from the angle, relative to the reference surface, of the radiant energy at which said shadow is cast, the position of at least one point on a surface of said object relative to another point on said object.
Claim 2
Independent Claim
127 words
A method of reconstructing the third dimension of an object comprising: disposing said object in a fixed position relative to a reference surface; projecting substantially parallel rays of radiant energy at said object at a plurality of different angles relative to said reference surface; recording the relative locations and lengths of each of the shadows cast by the object at each of said angles, said shadows including portions thereof formed on the reference surface; and determining from the length and relative location of each of said shadows cast and from the angle, relative to the reference surface, of the radiant energy at which said shadow is cast, the position of at least one point on a surface of said object relative to another point on said object.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein said radiant energy is light.
Claim 4
Dependent Claim
20 words
The method of claim 1 including determining the position of a plurality of points on said surface of said object.
Claim 5
Dependent Claim
35 words
The method of claim 3 including projecting said energy from each of a plurality of positions relative to said reference surface, all of said positions lying substantially in an azimuthal plane that intersects said object.
Claim 6
Dependent Claim
32 words
The method of claim 4 including recording said shadow lengths and locations in said azimuthal plane and wherein said determined points on a surface of said object lie within said azimuthal plane.
Claim 7
Dependent Claim
31 words
The method of claim 3 including projecting said energy from each of a plurality of positions relative to said reference surface, all of said positions lying substantially in an equatorial plane.
Claim 8
Dependent Claim
17 words
The method of claim 6 including determining said points by superposing at least two of said shadows.
Claim 9
Dependent Claim
22 words
The method of claim 1 including projecting said energy from a single source and moving said source relative to said reference surface.
Claim 10
Dependent Claim
27 words
The method of claim 1 including sequentially projecting said energy from each of a plurality of energy sources disposed at different orientations relative to said reference surface.
Claim 11
Dependent Claim
26 words
The method of claim 1 including projecting said energy from a single source and reflecting energy from said source of each of a plurality of mirrors.
Claim 12
Dependent Claim
26 words
The method of claim 1 including positioning a robot gripper in response to the determination of the position of at least one surface of said object.
Claim 13
Dependent Claim
25 words
The method of claim 1 including recording the location and length of each of said shadows by forming an image of each of said shadows.
Claim 14
Dependent Claim
27 words
The method of claim 12 including forming said images with an electronic camera to generate a plurality of electrical signals indicative of each of the shadow images.
Claim 15
Dependent Claim
27 words
The method of claim 13 including applying a threshold test to said plurality of signals and storing as a shadow each signal that falls below said threshold.
Claim 16
Dependent Claim
26 words
The method of claim 1 including disposing a wall higher than said object adjacent said object before projecting radiant energy and projecting energy over said wall.
Claim 17
Dependent Claim
40 words
The method of claim 1 including simultaneously projecting rays of radiant energy of at least two different wavelengths at said object and simultaneously and separately recording the relative locations and lengths of the shadows cast at each of said wavelengths.
Claim 18
Dependent Claim
29 words
The method of claim 1 wherein said shadow lengths and locations are recorded on a film in a camera and wherein said camera in open whenever energy is projected.
Claim 19
Independent Claim
130 words
An apparatus for reconstructing the third dimension of an object comprising: a reference surface with respect to which an object may be disposed; radiant energy source means for projecting substantially parallel rays of radiant energy from a plurality of different angles relative to said reference surface at a said object disposed relative to said reference surface; means for recording the relative locations and lengths of each of the shadows cast by said object at each of said plurality of different angles, said shadows including portions thereby formed on said reference surface; and means for determining the location of at least one point on a surface of said object relative to another point on said surface from the respective lengths and locations of said shadows cast and from the respective angles.
Claim 20
Independent Claim
130 words
An apparatus for reconstructing the third dimension of an object comprising: a reference surface with respect to which an object may be disposed; radiant energy source means for projecting substantially parallel rays of radiant energy from a plurality of different angles relative to said reference surface at a said object disposed relative to said reference surface; means for recording the relative locations and lengths of each of the shadows cast by said object at each of said plurality of different angles, said shadows including portions thereby formed on said reference surface; and means for determining the location of at least one point on a surface of said object relative to another point on said surface from the respective lengths and locations of said shadows cast and from the respective angles.
Claim 21
Dependent Claim
35 words
The apparatus of claim 18 wherein said energy source means comprises a source of substantially parallel rays of energy and means for positioning said source at a plurality of locations lying substantially in a plane.
Claim 22
Dependent Claim
24 words
The apparatus of claim 18 wherein said energy source means comprised a plurality of sources of substantially parallel rays disposed substantially within a plane.
Claim 23
Dependent Claim
33 words
The apparatus of claim 18 wherein said energy source means comprised a pivotally mounted source of substantially parallel rays of energy and a plurality of mirrors for reflecting energy received from said source.
Claim 24
Dependent Claim
35 words
The apparatus of claim 18 wherein said means for recording the location and length of each of said shadows comprises an electronic camera for generating a plurality of electrical signals indicative of a shadow image.
Claim 25
Dependent Claim
43 words
The apparatus of claim 19 wherein said means for determining comprises a computer for receiving from said means for recording length and location the recorded shadow lengths and locations and for determining the relative positions of at least one point on said surface.
Claim 26
Independent Claim
76 words
A method of reconstructing the third dimension of an object comprising: disposing said object in a fixed position relative to a reference surface; projecting substantially parallel rays of radiant energy at said object from a plurality of different equatorial positions relative to said reference surface; recording the shadows cast by the object from each of said positions; and determining from the recorded shadows the position of a plurality of points on a surface of said object.
Claim 27
Independent Claim
76 words
A method of reconstructing the third dimension of an object comprising: disposing said object in a fixed position relative to a reference surface; projecting substantially parallel rays of radiant energy at said object from a plurality of different equatorial positions relative to said reference surface; recording the shadows cast by the object from each of said positions; and determining from the recorded shadows the position of a plurality of points on a surface of said object.
Claim 28
Dependent Claim
17 words
The method of claim 24 including determining said points by superposing at least two of said shadows.
Claim 29
Dependent Claim
47 words
The method of claim 1 including determining the heights of different points on said surface of said object by computing the product of a function of the angle of the radiant energy and the difference between the locations of shadow edges at the angle of radiant energy.
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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |