APPARATUS AND METHOD FOR CAMERA CALIBRATION, AND VEHICLE

• US 20080186384A1
• Filed: 02/01/2008
• Published: 08/07/2008
• Est. Priority Date: 02/01/2007
• Status: Abandoned Application

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kano, Hiroshi, Ishii, Yohei, Okuda, Kozo, Asari, Keisuke
• Application Number:
  US12/024,716
• Publication Number:
  US 20080186384A1
• Time in Patent Office: Days
• US Class Current: 348/187
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
• CPC Class Codes: H04N 17/002 for television cameras

Abstract

A camera calibration apparatus has a parameter deriver adapted to find parameters for projecting an image shot with a camera onto a predetermined surface. The parameter deriver finds the parameters based on a shot-for-calibration image from the camera, and the shot-for-calibration image includes a plurality of calibration patterns of previously known shapes arranged at different positions within the shooting area of the camera.

Claims

1. A camera calibration apparatus comprising:

a parameter deriver adapted to find parameters for projecting an image shot with a camera onto a predetermined surface, wherein

the parameter deriver finds the parameters based on a shot-for-calibration image from the camera, and

the shot-for-calibration image includes a plurality of calibration patterns of previously known shapes arranged at different positions within a shooting area of the camera.

2. The camera calibration apparatus according to claim 1, wherein

the plurality of calibration patterns include a first calibration pattern and a second calibration pattern,

the parameter deriver

first finds initial parameters based on

coordinate information on the first calibration pattern on the shot-for-calibration image and

first previously known information on the shape of the first calibration pattern, and

then performs coordinate conversion on the second calibration pattern on the shot-for-calibration image by using the initial parameters and performs adjustment on the initial parameters based on

a shape of the second calibration pattern after the coordinate conversion and

second previously known information on this shape in order to find, through this adjustment, the parameters definitively.

3. The camera calibration apparatus according to claim 2, wherein

the first calibration pattern includes at least four characteristic points, and

the first previously known information identifies a positional relationship of the four characteristic points relative to one another.

5. A vehicle comprising:

a camera; and

an image processing apparatus, wherein

the image processing apparatus comprises the camera calibration apparatus according to claim 1.

4. A camera calibration apparatus comprising:

a parameter deriver adapted to find parameters for projecting an image shot with a camera onto a predetermined surface, wherein

the parameter deriver finds the parameters based on a shot-for-calibration image from the camera,

the shot-for-calibration image includes a calibration pattern of a previously known shape arranged inside a shooting area of the camera, and

the parameter deriver

performs coordinate conversion on the calibration pattern on the shot-for-calibration image by using initial parameters based on previously set information and

then performs adjustment on the initial parameters based on a shape of the calibration pattern after the coordinate conversion and previously known information on this shape

in order to find, through this adjustment, the parameters definitively.

6. A vehicle comprising:

a camera; and

an image processing apparatus, wherein

the image processing apparatus comprises the camera calibration apparatus according to claim 4.

7. A camera calibration method for finding parameters for projecting an image shot with a camera onto a predetermined surface, comprising:

a parameter derivation step of finding the parameters based on a shot-for-calibration image from the camera, wherein

the shot-for-calibration image includes a plurality of calibration patterns of previously known shapes arranged at different positions within a shooting area of the camera.

8. A camera calibration method for finding parameters for projecting an image shot with a camera onto a predetermined surface, comprising:

a parameter derivation step of finding the parameters based on a shot-for-calibration image from the camera, wherein

the shot-for-calibration image includes a calibration pattern of a previously known shape arranged inside a shooting area of the camera, and

the parameter derivation step comprises a parameter adjustment step in which

coordinate conversion is performed on the calibration pattern on the shot-for-calibration image by using initial parameters based on previously set information and then

adjustment is performed on the initial parameters based on a shape of the calibration pattern after the coordinate conversion and previously known information on this shape,

so that, through this adjustment, the parameters are definitively found.