Distance measurement apparatus, distance measurement method, and distance measurement program

• US 20040233280A1
• Filed: 05/05/2004
• Published: 11/25/2004
• Est. Priority Date: 05/19/2003
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Aoyama, Chiaki
• Granted Patent: US 7,659,921 B2
• Time in Patent Office: Days
• US Class Current: 348/135
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06T 7/85 Stereo camera calibration
• 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 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 2013/0096 Synchronisation or controlling aspects
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

Captured images taken by cameras are corrected in accordance with characteristics of the lens system of the cameras to produce corrected images. A pixel position detector then obtains the pixel position of the object on each corrected image. With reference to calibration tables, each of which correlates one of a pixel position on a coordinate system of each corrected image and information having a predetermined relation to the pixel position with information specifying a direction and a position of incident light traveling to the pixel position, the direction and the position of the incident light are obtained. Based on the direction and the position of the incident light, the distance to the object OB can be calculated.

Claims

1. A distance measurement apparatus for measuring a distance to an object based on captured images taken by a plurality of cameras, comprising:

a plurality of cameras;

a distortion correction executing means which corrects distortion of the captured images according to characteristics of an optical system used for each camera and produces corrected images;

a calibration information storage means which stores calibration information correlating one of a pixel position on a coordinate system of each corrected image and information having a predetermined relation to the pixel position with information specifying a direction and a position of incident light traveling to the pixel position;

a pixel position detecting means which detects a pixel position of the object on each corrected image; and

a distance calculating means which obtains a direction and a position of the incident light traveling to the pixel position of the object on each corrected image by referring to the calibration information, and calculates the distance to the object based on the direction and the position of the incident light.

2. A distance measurement apparatus according to claim 1, wherein information specifying the direction and the position of the incident light contains a direction of the incident light and a displacement amount from a reference position to the incident light.

3. A distance measurement apparatus according to claim 1, wherein information specifying the direction and the position of the incident light is coordinates of two points positioned on the incident light.

4. A method of measuring a distance to an object based on captured images taken by a plurality of cameras and with the use of calibration information, which correlates one of a pixel position on each corrected image that is prepared by correcting distortion of the captured images taken by the cameras and information having a predetermined relation to the pixel position with information specifying a direction and a position of incident light traveling to the pixel position, the method comprising:

a distortion correction executing step of correcting distortion of the captured images according to characteristics of an optical system used for each camera and producing corrected images;

a pixel position detecting step of detecting a pixel position of the object on each corrected image; and

a distance calculating step of obtaining a direction and a position of incident light traveling to the pixel position of the object on each corrected image by referring to the calibration information and calculating the distance to the object from the direction and the position of the incident light.

6. A distance measurement method according to claim 4, wherein information specifying the direction and the position of the incident light contains a direction of the incident light and a displacement amount from a reference position to the incident light.

7. A distance measurement method according to claim 4, wherein information specifying the direction and the position of the incident light is coordinates of two points positioned on the incident light.

5. A distance measurement program for measuring a distance to an object based on captured images taken by a plurality of cameras with the use of calibration information, which correlates one of a pixel position on each corrected image that is prepared by correcting distortion of the captured images taken by the cameras and information having a predetermined relation to the pixel position with information specifying a direction and a position of incident light traveling to the pixel position, the distance measurement program being configured to cause a computer to operate as:

a distortion correction executing means for producing corrected images by correcting distortion of the captured images according to characteristics of an optical system used for each camera;

a pixel position detecting means for detecting a pixel position of the object on each corrected image; and

a distance calculating means for obtaining a direction and a position of incident light traveling to the pixel position of the object on each corrected image by referring to the calibration information and calculating the distance to the object from the direction and the position of the incident light.

8. A distance measurement program according to claim 5, wherein information specifying the direction and the position of the incident light contains a direction of the incident light and a displacement amount from a reference position to the incident light.

9. A distance measurement program according to claim 5, wherein information specifying the direction and the position of the incident light is coordinates of two points positioned on the incident light.