Positional deviation adjusting apparatus of stereo image

• US 6,552,742 B1
• Filed: 09/14/2000
• Issued: 04/22/2003
• Est. Priority Date: 09/16/1999
• Status: Expired due to Term

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Inventors: Seta, Itaru
• Primary Examiner(s): DIEP, NHON THANH
• Application Number:
  US09/661,790
• Time in Patent Office: 950 Days
• Field of Search: H04/N 1.302, H04/N 1.300, H04/N 1.500, 348/42, 348/47, 348/43, 353/7, 352/57, 376/322, 376/324, 376/325
• US Class Current: 348/42
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/85 Stereo camera calibration
• CPC Class Codes: H04N 13/111 Transformation of image signals corresponding to virtual viewpoints, e.g. spatial image interpolation
• CPC Class Codes: H04N 13/167 Synchronising or controlling image signals
• 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 13/25 using two or more image sensors with different characteristics other than in their location or field of view, e.g. having different resolutions or colour pickup characteristics; using image signals from one sensor to control the characteristics of another sensor
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals
• CPC Class Codes: H04N 2013/0096 Synchronisation or controlling aspects

Abstract

A positional deviation adjusting apparatus of a stereoscopic camera includes a correction circuit for transforming images geometrically according to transformation parameters and a calculating section. A plurality of reference areas are established on a reference line of one image and a reference point is established for every reference area. The calculating section identifies correlation points having a correlation with the respective reference points in the other image. Further, the calculating section calculates an approximation line based on the correlation points and corrects the transformation parameters in such a manner that the approximation line coincides with the reference line.

Claims

1. A positional deviation adjusting apparatus of a stereoscopic camera for adjusting a positional deviation of a first image with respect to a second image, comprising:

image correcting means for transforming said first and second images geometrically according to transformation parameter, respectively;

reference area establishing means for establishing a plurality of reference areas in said first image transformed by said image correcting means;

reference point establishing means for establishing a reference point in each of said reference areas;

reference line establishing means for establishing a reference line passing through each said reference point;

searching area establishing means for establishing a searching area corresponding to said reference areas in said second image;

correlation point identifying means for identifying a correlation point having a correlation with said reference point for each of said searching areas;

approximation line calculating means for calculating an approximation line based on said correlation point; and

parameter correcting means for correcting said transformation parameter such that said approximation line coincides with said reference line.

5. The apparatus according to claim 1, wherein said transformation parameter is at least either a transformation parameter representing a rotation of said second image or a transformation parameter representing a vertical movement of said second image.

7. The apparatus according to claim 1, wherein said reference areas are established in the horizontal direction of said first image and the number of said reference areas is at least 3.

2. A positional deviation adjusting apparatus of a stereoscopic camera for adjusting a positional deviation of a first image with respect to a second image, comprising:

image correcting means for transforming said first and second images geometrically according to transformation parameter, respectively;

stereo calculating means for calculating a distance data based on a brightness correlation between said first image and said second image;

reference area establishing means for establishing a plurality of reference areas in said first image transformed by said image correcting means;

reference point establishing means for establishing a reference point in each of said reference areas;

reference line establishing means for establishing a reference line passing through each said reference point;

searching area establishing means for establishing a searching area corresponding to said reference areas in said second image according to said distance data;

correlation point identifying means for identifying a correlation point having a correlation with said reference point for each of said searching areas;

approximation line calculating means for calculating an approximation line based on said correlation point; and

parameter correcting means for correcting said transformation parameter such that said approximation line coincides with said reference line.

3. The apparatus according to claim 2, wherein said searching area is established based on distance data in said reference area so as to include an area having a brightness correlation with said reference area.

4. The apparatus according to claim 2, wherein said searching area is established based on a distance value most frequently observed among distance data.

6. The apparatus according to claim 2, wherein said transformation parameter is at least either a transformation parameter representing a rotation of said second image or a transformation parameter representing a vertical movement of said second image.

8. The apparatus according to claim 2, wherein said reference areas are established in the horizontal direction of said first image and the number of said reference areas is at least 3.

9. The apparatus according to claim 2, wherein said correlation point is identified when distance data is larger than a specified value.

10. The apparatus according to claim 2, wherein said correlation point is identified when distance data is within a specified range.

11. The apparatus according to claim 2, wherein said correlation point is identified when the number of said brightness edges is larger than a first threshold value specifying a minimum value of the number of brightness edges.

12. The apparatus according to claim 2, wherein the apparatus counts brightness edges having brightness differences in said reference area, and said correlation point is identified when the number of said brightness edges is smaller than a second threshold value specifying a maximum value of the number of brightness edges.

13. A positional deviation adjusting apparatus of a stereoscopic camera for adjusting a positional deviation of a first image with respect to a second image, comprising:

image correcting means for transforming said first and second images geometrically according to transformation parameter, respectively;

reference area establishing means for establishing a plurality of reference areas in said first image transformed by said image correcting means, said reference areas being established so as to align on a straight line;

searching area establishing means for establishing a search area corresponding to said reference areas and said second image;

correlation point identifying means for identifying a correlation point having a correlation with said reference point for each of said searching areas;

approximation line calculating means for calculating an approximation line based on said correlation point; and

parameter correcting means for correcting said transformation parameter according to deviations between said straight line and said approximation line.