Stereo camera apparatus with a main camera and a sub-camera where the sub-camera has a point of view difference from the point of view of the main camera

• US 7,106,365 B1
• Filed: 09/21/2000
• Issued: 09/12/2006
• Est. Priority Date: 09/22/1999
• Status: Expired due to Term

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Sogawa, Yoshiyuki
• Primary Examiner(s): Ometz, David
• Assistant Examiner(s): SELBY, GEVELL V
• Application Number:
  US09/667,424
• Time in Patent Office: 2,182 Days
• Field of Search: 348/373, 348/116, 348/333.06, 348/118, 348/148, 348/222.1, 348/207.99, 358/88, 358/229, 358/3, 358/209, 352/57, 382/106, 382/154, 356/3, 356/314, 356/12, 396/128
• US Class Current: 348/222.1
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: B60R 11/04 Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle
• CPC Class Codes: G03B 15/00 Special procedures for taking photographs; Apparatus therefor
• CPC Class Codes: G03B 35/08 by simultaneous recording
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• 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 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

A stereo camera unit 2 is constructed mainly of a main camera 4, a sub-camera 5 and a camera stay 3. The main camera 4 and the sub-camera 5 are assembled to the camera stay 3 in such a way that they are inclined toward the main camera 4 side with respect to a central axis of the vehicle.

Claims

1. A stereo camera apparatus comprising:

a main camera for taking a photograph of an object; and

a sub-camera for taking a photograph of said object from a point of view different from a point of view of said main camera, said main camera and said sub-camera being disposed with respect to each other by a predetermined spacing,

a shooting direction of said stereo camera is substantially perpendicular to said predetermined spacing in a baseline between the main camera and the sub-camera,

image processing means for calculating a three-dimensional distance distribution of said object based on a positional difference between a region in a reference image photographed by said main camera and a corresponding area in a comparative image photographed by said sub-camera to an image signal of said region,

wherein said corresponding area is searched in a striplike search area having a predetermined length which extends from a position substantially corresponding to said region, said positional difference is obtained from an area which is capable of setting said search area inside of said comparative image,

wherein optical axes of said main camera and said sub-camera are inclined toward the main camera side with a predetermined angle with respect to the shooting direction defined by each of the optical axes and the shooting direction,

wherein angles of inclination of said main camera and said sub-camera are set to be such angles that said three-dimensional distance distribution is substantially left-right symmetric with respect to the shooting directions

wherein angles of inclination of said main camera and said sub-camera are set to be angles such that said three-dimensional distance distribution is substantially left-right symmetric with respect to a central axis of a vehicle parallel to a forward direction of the vehicle, and the shooting direction being parallel to the central axis.

2. The stereo camera apparatus as recited in claim 1, further comprising:

a camera stay for mounting said cameras thereon, wherein a longitudinal direction of said camera stay is substantially perpendicular to the shooting direction.

3. The stereo camera apparatus as recited in claim 1, wherein each of said camera is a CCD camera.

4. The stereo camera apparatus as recited in claim 1, wherein said cameras are mounted in the vicinity of a rear-view mirror of a vehicle, said cameras taking photographs of views outside the vehicle.

5. The stereo camera apparatus as recited in claim 1,

wherein said predetermined length of said search area is longer than length of said region.

6. A stereo camera apparatus comprising:

a main camera for taking a photograph of an object; and

a sub-camera for taking a photograph of said object from a point of view different from a point of view of said main camera, said main camera and said sub-camera being disposed with respect to each other by a predetermined spacing,

a shooting direction of said stereo camera is substantially perpendicular to said predetermined spacing in a baseline between the main camera and the sub-camera,

image processing means for calculating a three-dimensional distance distribution of said object based on a positional difference between a region in a reference image photographed by said main camera and a corresponding area in a comparative image photographed by said sub-camera to an image signal of said region,

wherein said corresponding area is searched in a striplike area having a predetermined length which extends from a position substantially corresponding to said region,

said positional difference is obtained from an area which is capable of setting search area inside of said comparative image,

wherein said main camera and said sub-camera are inclined toward the main camera side with a predetermined angle with respect to the shooting direction defined by each of the optical axes and the shooting direction,

wherein angles of inclination of said main camera and said sub-camera are set to be such angles that said three-dimensional distance distribution is substantially left-right symmetric with respect to the shooting direction,

wherein the optical axis of said sub-camera is inclined toward said sub-camera side with respect to the optical axis of said main camera,

wherein the optical axis of said sub-camera is inclined toward said sub-camera side with respect to the optical axis of said main camera in order to provide a search margin in a comparative image photographed by said sub-camera to enable detection of an infinite distance corresponding point positioned at an end of said sub-camera side in a reference image taken by said main camera,

wherein angles of inclination of said main camera and said sub-camera are set to be angles such that said three-dimensional distance distribution being substantially left-right symmetric with respect to a central axis of a vehicle parallel to the forward direction of the vehicle and said shooting direction being parallel to the central axis.

7. The stereo camera apparatus as recited in claim 6, wherein the optical axis of said sub-camera is inclined toward said sub-camera side with respect to the optical axis of said main camera in order to provide a search margin in a comparative image photographed by said sub-camera to enable detection of an infinite distance corresponding point positioned at an end of said sub-camera side in a reference image taken by said main camera.

8. A stereo camera apparatus comprising:

a main camera for taking a photograph of an object; and

a sub-camera for taking a photograph of said object from a point of view different from a point of view of said main camera, said main camera and said sub-camera being disposed with respect to each other by a predetermined spacing,

a shooting direction of said stereo camera is substantially perpendicular to said predetermined spacing in a baseline between the main camera and the sub-camera,

image processing means for calculating a three-dimensional distance distribution of said object on a positional difference between a region in a reference image photographed by said main camera and a corresponding area in a comparative image photographed by said sub-camera to an image signal of said region,

wherein said corresponding area is searched in a striplike area having a predetermined length which extends from a position substantially corresponding to said region,

said positional difference is obtained from an area which is capable of setting search area inside of said comparative image,

wherein said main camera and said sub-camera are inclined toward the main camera side with a predetermined angle with respect to the shooting direction defined by each of the optical axes and the shooting direction,

wherein angles of inclination of said main camera and said sub-camera are set to be such angles that said three-dimensional distance distribution is substantially left-right symmetric with respect to the shooting direction,

wherein a first acute angle defined between said optical axis of said main camera and the baseline is smaller than a second acute angle defined between said optical axis of said sub-camera and the baseline;

wherein angles of inclination of said main camera and said sub-camera are set to be angles such that said three-dimensional distance distribution being substantially left-right symmetric with respect to a central axis of a vehicle parallel to the forward left-right symmetric with respect to a central axis of a vehicle parallel to the forward direction of the vehicle, and said shooting direction being parallel to the central axis.

9. The stereo camera apparatus as recited in claim 8,

wherein the first acute angle is smaller than the second acute angle in order to provide a search margin in a comparative image photographed by said sub-camera to enable detection of an infinite distance corresponding point positioned at an end of said sub-camera side in a reference image taken by said main camera.

10. A stereo camera apparatus comprising:

a main camera for taking a photograph of an object; and

a sub-camera for taking a photograph of said object from a point of view different from a point of view of said main camera, said main camera and said sub-camera being disposed with respect to each other by a predetermined spacing,

a shooting direction of said stereo camera is substantially perpendicular to said predetermined spacing in a baseline between the main camera and the sub-camera,

image processing means for calculating a three-dimensional distance distribution of said object based on a positional difference between a region in a reference image photographed by said main camera and a corresponding area in a comparative image photographed by said sub-camera to an image signal of said region,

wherein said corresponding area is searched in a striplike search area having a predetermined length which extends from a position substantially corresponding to said region, said positional difference is obtained from an area which is capable of setting said search area inside of said comparative image,

wherein optical axes of said main camera and said sub-camera are inclined toward the main camera side with a predetermined angle with respect to the shooting direction defined by each of the optical axes and the shooting direction,

wherein angles of inclination of said main camera and said sub-camera are set to be such angles that said three-dimensional distance distribution is substantially left-right symmetric with respect to the shooting direction,

wherein angles of inclination of said main camera and said sub-camera are set to be angles that said three-dimensional distance distribution being substantially left-right symmetric with respect to a central axis of a vehicle parallel to a forward direction of the vehicle, and the shooting direction being parallel to the central axis;

wherein said angles of inclination of said main camera and said sub-camera correspond to a displacement between a first line on said reference image and a second line on said reference image,

said first line is a line for setting a three-dimensional distance distribution, generating area on said reference image substantially symmetrical on left and right sides with respect to said first line in said reference image

said second line is a vertical line perpendicular to said optical axis of said main camera in said reference image.