Calibration method and device, device for generating calibration data and a method thereof, and information providing medium

• US 6,377,701 B1
• Filed: 10/09/1998
• Issued: 04/23/2002
• Est. Priority Date: 10/17/1997
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ohki, Mitsuharu
• Primary Examiner(s): Mehta, Bhavesh
• Assistant Examiner(s): Bayat, Ali
• Application Number:
  US09/169,375
• Time in Patent Office: 1,292 Days
• Field of Search: 382/152, 382/154, 382/153, 382/284, 382/294, 382/285, 356/3, 356/14, 356/12, 356/631, 250/559.23, 250/559.31, 348/47, 348/50, 345/419, 345/629, 345/630
• US Class Current: 382/154
• CPC Class Codes: G01C 11/06 by comparison of two or more pictures of the same area
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06T 7/85 Stereo camera calibration
• CPC Class Codes: H04N 13/189 Recording image signals; Reproducing recorded image signals
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/246 Calibration of cameras
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

A plate 5 provided with a square lattice-work pattern thereupon is provided in the same space with two cameras 1 and 2 and a theodolite 4. This plate—unlike known plates, which have been around 4 meters by 3 meters in size and consequently so great as to make precise drawing of the square lattice-work pattern difficult, resulting in calibration with low precision—is about 1.5 meters by 1 meter in size, for example. As the plate is small, a precise square lattice-work pattern can be drawn thereupon. The theodolite 4 measures 3-dimensional coordinates for at least two set positions of the plate 5. Then, calibration is performed using the image data obtained by the two cameras 1 and 2 imaging the square lattice-work pattern and the 3-dimensional coordinates measured with the theodolite.

Claims

1. A calibration method for calibrating an imaging device for determining positional information of an object in a 3-dimensional space based on 2-dimensional images obtained from said imaging device,

wherein calibration of said imaging device is carried out based on:

at least two 3-dimensional coordinates positions of a reference object set within a 3-dimensional space corresponding to a range in which said imaging device performs imaging, each of the at least two positions corresponding to a respective covered portion of a screen of said imaging device; and

image data obtained by said imaging device performing imaging of said reference object at each set position.

2. A calibration method according to claim 1, wherein a group of points on the 3-dimensional space projected to each position of the screens of said imaging device is calculated, by means of finding the 3-dimensional coordinates position of a pattern on said reference object which is projected to each position of the screens of said imaging device.

3. A calibration method according to claim 2, wherein a square lattice-work pattern is drawn on said reference object.

4. A calibration method according to claim 2, wherein said group of points is a collection of points on a line.

5. A calibration method according to claim 1, wherein a theodolite is used as a 3-dimensional positional information measuring machine for measuring said 3-dimensional positions.

6. A calibration method according to claim 1, wherein a total station is used as a 3-dimensional positional information measuring machine for measuring said 3-dimensional positions.

7. A calibration device for calibrating an imaging device for determining positional information of an object in a 3-dimensional space based on 2-dimensional images obtained from said imaging device, said calibration device comprising:

a reference object set in a 3-dimensional space within a range in which said imaging device performs imaging of said object;

3-dimensional position information measuring means for measuring a 3-dimensional coordinate position of said reference object; and

control means for generating calibration information for said imaging device, based on at least two 3-dimensional coordinates positions of said reference object set within a 3-dimensional space corresponding to said range in which said imaging device performs imaging, each of the at least two positions corresponding to a respective covered portion of a screen of said imaging device; and

image data obtained by said imaging device performing imaging of said reference object at each set position.

8. A calibration device according to claim 7, wherein said control means calculates a group of points on the 3-dimensional space projected to each position of the screens of said imaging device, by means of finding the 3-dimensional coordinates position of a pattern on said reference object which is projected to each position of the screens of said imaging device.

9. A calibration device according to claim 8, wherein a square lattice-work pattern is drawn on said reference object.

10. A calibration device according to claim 8, wherein said group of points is a collection of points on a line.

11. A calibration device according to claim 8, wherein a theodolite is used as said 3-dimensional positional information measuring machine.

12. A calibration device according to claim 7, wherein a total station is used as said 3-dimensional positional information measuring machine.

13. A calibration data generating method for generating data for calibrating an imaging device which determines positional information of an object in a 3-dimensional space based on 2-dimensional images obtained from said imaging device, said method comprising the steps of:

receiving data indicating 3-dimensional position information of said reference object which has been measured multiple times by a 3-dimensional position information measuring device;

receiving image data of said reference object which has been measured multiple times by said imaging device; and

generating data for calibration for said imaging device, based on obtaining a 3-dimensional space position from at least two positions of said reference object set within a 3-dimensional space corresponding to portions of a screen of said imaging device which corresponds to a range in which said imaging device performs imaging, and image data obtained by said imaging device performing imaging of said reference object at each set position.

14. A calibration data generating method according to claim 13, wherein a theodolite is used as said 3-dimensional positional information measuring machine.

15. A calibration data generating method according to claim 13, wherein a total station is used as said 3-dimensional positional information measuring machine.

16. A calibration data generating method according to claim 13, wherein said calibration data on said 3-dimensional space is a collection of points on a line projected on each position of the screens of said imaging device.

17. A calibration data generating device for generating data for calibrating an imaging device which determines positional information of an object in a 3-dimensional space based on 2-dimensional images obtained from said imaging device, said calibration data generating device comprising;

a first receiving unit for receiving data indicating 3-dimensional position information of said reference object which has been measured multiple times by a 3-dimensional position information measuring device;

a second receiving unit for receiving image data of said reference object which has been measured multiple times by said imaging device; and

a control unit for generating data for calibration for said imaging device, based on obtaining a 3-dimensional space position from at least two positions of said reference object set within a 3-dimensional space corresponding to portions of a screen of said imaging device which corresponds to a range in which said imaging device performs imaging, and image data obtained by said imaging device performing imaging of said reference object at each set position.

18. A calibration data generating device according to claim 17, wherein a theodolite is used as said 3-dimensional positional information measuring machine.

19. A calibration data generating device according to claim 17, wherein a total station is used as said 3-dimensional positional information measuring machine.

20. A calibration data generating method according to claim 17, wherein said calibration data on said 3-dimensional space is a collection of points on a line projected on each position of the screens of said imaging device.

21. An information providing medium which provides control information for calibrating an imaging device for determining positional information of an object in a 3-dimensional space based on 2-dimensional images obtained from said imaging device,

wherein calibration of said imaging device is carried out based on:

at least two 3-dimensional coordinates positions of said reference object set within a 3-dimensional space corresponding to a range in which said imaging device performs imaging, each of the at least two positions corresponding to a respective covered portion of a screen of said imaging device; and

image data obtained by said imaging device performing imaging of said reference object at each set position.