Apparatus and method for stereoscopic image processing

• US 6,381,360 B1
• Filed: 09/21/2000
• Issued: 04/30/2002
• 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): Johns, Andrew W.
• Assistant Examiner(s): AZARIAN, SEYED H
• Application Number:
  US09/665,947
• Time in Patent Office: 586 Days
• Field of Search: 382/154, 382/153, 382/151, 382/294, 382/278, 348/113, 348/116, 348/118, 348/117, 348/122, 348/127, 348/143, 348/148
• US Class Current: 382/154
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60
• CPC Class Codes: G06V 2201/12 Acquisition of 3D measurements of objects

Abstract

After processing images photographed by a stereo camera apparatus, parallaxes are detected by stereo matching. Influence of a difference in the focal lengths of lenses and distortion of the lenses, and of relative variations in shooting directions of two cameras constituting the stereo camera apparatus is excluded to achieve an improvement in the accuracy of distance by correcting parallax data using a view angle correction ratio table 29 produced by previously measuring data on a small actual view angle of each specific region in a comparative image.

Claims

1. A stereoscopic image processing apparatus comprising:

a search unit for searching a corresponding small region in a comparative image corresponding to a small region in a reference image, the comparative image and the reference image being photographed with a stereo camera apparatus;

a parallax calculating unit for obtaining a parallax data of the small regions; and

a parallax correcting unit for correcting the parallax data based on ratios of view angles, the ratio of view angles being a ratio of a small actual view angle of each predetermined region in the comparative image to an ideal view angle of the each predetermined region when optical position of the stereo camera apparatus is in an ideal state.

2. The stereoscopic image processing apparatus as recited in claim 1, wherein said parallax correcting unit corrects the parallax data on the basis of the ratio of view angles corresponding to a matching point in the comparative image where the corresponding small region matches with the small region in the reference image, and the ratio of view angles corresponding to an infinite distance corresponding point for the small region.

3. The stereoscopic image processing apparatus as recited in claim 1, wherein said parallax correcting unit has a correction data table based on the ratio of view angles, and corrects the parallax data in reference to correction data of said correction data table.

4. The stereoscopic image processing apparatus as recited in claim 3, wherein said correction data table includes a first table to be referenced at matching points in the comparative image where the corresponding small regions match with the small regions in the reference image and a second table to be referenced at infinite distance corresponding points.

5. The stereoscopic image processing apparatus as recited in claim 1, wherein said parallax correction unit corrects the parallax data based on integrated values obtained by integrating the ratio of the view angles from an side edge of the comparative image.

6. The stereoscopic image processing apparatus as recited in claim 3, wherein correction data of said correction data table are integrated values obtained by integrating the ratio of the view angles from a side edge of the comparative image.

7. The stereoscopic image processing apparatus as recited in claim 4, wherein correction data of the first table and the second table are integrated values obtained by integrating the ratio of the view angles from a side edge of the comparative image.

8. A stereoscopic image processing method comprising:

searching a corresponding small region in a comparative image corresponding to a small region in a reference image, the comparative image and the reference image being photographed with a stereo camera apparatus;

obtaining a parallax data of the small regions; and

correcting the parallax data based on a ratio of view angles, the ratio of view angles being a ratio of a small actual view angle of each predetermined region in the comparative image to an ideal view angle of the each predetermined region when optical position of the stereo camera apparatus is in an ideal state.

9. The stereoscopic image processing method as recited in claim 8, wherein said step of correcting the parallax corrects the parallax data on the basis of the ratio of view angles corresponding to a matching point in the comparative image where the corresponding small region matches with the small region in the reference image, and the ratio of view angles corresponding to an infinite distance corresponding point.

10. The stereoscopic image processing method as recited in claim 8, wherein said step of correcting the parallax comprises:

preparing a correction data table based on the ratio of view angles; and

correcting the parallax based on correction data of the correction data table.

11. The stereoscopic image processing method as recited in claim 10, wherein said step of preparing correction data table prepares a first table to be referenced at matching points in the comparative image where the corresponding small regions match with the small regions in the reference image and a second table to be referenced at infinite distance corresponding points.

12. The stereoscopic image processing method as recited in claim 8, wherein said step of correction the parallax corrects the parallax data based on integrated values obtained by integrating the ratio of the view angles from an side edge of the comparative image.

13. The stereoscopic image processing method as recited in claim 10, wherein said step of correction the parallax prepares the correction data table based on integrated values obtained by integrating the ratio of the view angles from an side edge of the comparative image.

14. The stereoscopic image processing method as recited in claim 11, wherein said step of correction the parallax prepares the first table and the second table based on integrated values obtained by integrating the ratio of the view angles from an side edge of the comparative image.