Calibration Apparatus of On-Vehicle Camera, Program, and Car Navigation System

• US 20080007619A1
• Filed: 06/28/2007
• Published: 01/10/2008
• Est. Priority Date: 06/29/2006
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Shima, Takeshi, Otsuka, Yuji, Muramatsu, Shoji, Monji, Tatsuhiko, Irie, Kota
• Granted Patent: US 8,212,878 B2
• Time in Patent Office: Days
• US Class Current: 348/118
• 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

Abstract

An on-vehicle camera calibration apparatus includes: an on-vehicle camera; a camera parameter calculation unit configured to calculate camera parameters from a characteristic amount of a road surface sign photographed by the on-vehicle camera and recognized by an image processing and to output the camera parameters, wherein the camera parameters include an installation height and installation angle of the on-vehicle camera in photographing; and a camera parameter calibration unit configured to perform optical axis calibration control of the on-vehicle camera by the camera parameters output from the camera parameter calculation unit.

Claims

1. An on-vehicle camera calibration apparatus comprising:

an on-vehicle camera;

a camera parameter calculation unit configured to calculate camera parameters from a characteristic amount of a road surface sign photographed by the on-vehicle camera and recognized by an image processing and to output the camera parameters, wherein the camera parameters include an installation height and installation angle of the on-vehicle camera in photographing; and

a camera parameter calibration unit configured to perform optical axis calibration control of the on-vehicle camera by the camera parameters output by the camera parameter calculation unit.

2. The on-vehicle camera calibration apparatus according to claim 1, wherein when the road surface sign is different in any one of a dimension and a shape according to an area, the camera parameter calculation unit identifies the area based on vehicle position information acquired from outside, acquires a reference characteristic amount of the road surface sign matching with the dimension and the shape, and calculates the camera parameters.

3. The on-vehicle camera calibration apparatus according to claim 1, wherein the camera parameter calibration unit determines whether or not a user'"'"'s own vehicle is in a state being suitable for a calibration of the on-vehicle camera, and wherein when the user'"'"'s own vehicle is not in the state being suitable for the calibration, the camera parameter calibration unit keeps the on-vehicle camera from photographing an image.

4. The on-vehicle camera calibration apparatus according to claim 1, wherein the camera parameter calibration unit further compares thresholds on the installation height and the installation angle memorized in a memory device in advance with the calculated camera parameters, and wherein when at least of the calculated camera parameters is determined to exceed the threshold, the camera parameter calibration unit outputs the determination result outside.

5. A program used for an on-vehicle camera calibration apparatus configured to perform an optical axis calibration of an on-vehicle camera by an image processing device, the program making a computer execute the steps of:

calculating camera parameters from a characteristic amount of a road surface sign photographed by the on-vehicle camera and recognized by an image processing and outputting the camera parameters, wherein the camera parameters include an installation height and installation angle of the on-vehicle camera in photographing; and

performing optical axis calibration control of the on-vehicle camera by the calculated and output the camera parameters.

6. A car navigation system comprising:

an on-vehicle camera;

an image processing device configured to calculate camera parameters from a characteristic amount of a road surface sign photographed by the on-vehicle camera and recognized by an image processing and to perform optical axis calibration control of the on-vehicle camera, wherein the camera parameter, include an installation height and installation angle of the on-vehicle camera in photographing; and

an ITS (Intelligent Transportation System) configured to perform a current position calibration of a user'"'"'s own vehicle, using a distance from the user'"'"'s own vehicle to the photographed and recognized road surface sign calculated by the image processing device.