Pattern-matching processing method and image processing apparatus

• US 20040022418A1
• Filed: 07/31/2003
• Published: 02/05/2004
• Est. Priority Date: 07/31/2002
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Oota, Akihiro
• Granted Patent: US 7,386,192 B2
• Time in Patent Office: Days
• US Class Current: 382/106
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06V 10/24 Aligning, centring, orientation detection or correction of the image

Abstract

The present invention relates to a pattern-matching processing method based on left and right images of an object photographed in stereo. A left area and a right area are generated, each having a fixed pattern containing plural pixels extracted from the left and right images, respectively, and in the left area, a reference image is generated by calculating an interpolation pixel value to be used between two transversely adjacent pixels based on the average of the two pixel values, and by calculating an interpolation pixel value to be used between two vertically adjacent pixels based on the average of the plural pixel values surrounding the relating position. Similarly, in the right area, interpolation pixel values are calculated and a comparison image is generated. Then pattern matching is performed between the reference image and the comparison images generated sequentially by shifting the right original image pixel by pixel.

Claims

1. A pattern-matching processing method, comprising an area generating step for generating a left area and a right area each having a given range from a left image and a right image photographed in stereo, a pixel generating step for generating an interpolation pixel between pixels contained in the left area or the right area, and a pattern-matching step for performing pattern matching using the left area and the right area.

2. A pattern-matching processing method, as set forth in claim 1, wherein pattern matching is performed based on said left area and said right area containing the interpolation pixel, in said pattern-matching step.

3. A pattern-matching processing method, as set forth in claim 1, wherein pattern matching is performed based on said left area and said right area interpolated with the interpolation pixel, in said pattern-matching step.

4. A pattern-matching processing method, as set forth in claim 1, wherein pixel interpolation is performed on a left area and a right area containing a pixel at the center, the matching position of which has been specified by pattern matching based on the left area and the right area, in said pixel generating step.

5. A pattern-matching processing method, as set forth in claim 1, wherein pixel interpolation is performed on a right area containing a pixel at the center, the matching position of which has been specified by pattern matching based on the left area and the right area, in said pixel generating step.

6. A pattern-matching processing method, as set forth in claim 1 wherein, after pixel interpolation is performed between two transversely adjacent pixels in said left area or said right area, pixel interpolation is performed between two vertically adjacent pixels relating to the position to be interpolated, in said pixel generating step.

7. A pattern-matching processing method, as set forth in claim 1 wherein, after pixel interpolation is performed between two transversely adjacent pixels in said left area or said right area, pixel interpolation is performed between two vertically adjacent pixels based on the average value of plural pixels surrounding the position to be interpolated, in said pixel generating step.

8. A pattern-matching processing method, as set forth in claim 7, wherein the plural pixels surrounding the position to be interpolated are weighted when the average value is calculated, in said pixel generating step.

9. A pattern-matching processing method, as set forth in claim 7, wherein pixel interpolation is performed starting from the pixel position at which the number of pixels surrounding the position to be interpolated is largest, which is the target for which the average value is calculated, in said pixel generating step.

10. A pattern-matching processing method, as set forth in claim 7, wherein said average value is calculated after weighting a value less than 1 to the already interpolated pixels among the plural pixels surrounding the position to be interpolated, in said pixel generating step.

11. A pattern-matching processing method, as set forth in claim 1, wherein pixel interpolation is performed based on two pixels adjacent to each other only in the transverse direction in said left area and said right area, in said pixel generating step.

12. An image processing apparatus measuring the distance to an object that is photographed as images, by performing pattern-matching processing based on left and right images photographed by a stereo camera, and comprising a pixel generating unit for generating a left area and a right area each having a fixed range from the left image and the right image and for generating interpolation pixels between pixels contained in the left area or the right area, a pattern-matching processing unit having a pattern-matching unit performing pattern matching on the left area and the right area, and a distance measuring unit for calculating the distance from the difference in positions of the left image and the right image based on the matching position specified by performing pattern matching on the left area and the right area.

13. An image processing apparatus, as set forth in claim 12, wherein said pattern-matching processing unit performs pattern matching based on said left area and said right area containing the interpolation pixel.

14. An image processing apparatus, as set forth in claim 12, wherein said pattern-matching processing unit performs pattern matching based on said left area and said right area interpolated with the interpolation pixel.

15. An image processing apparatus, as set forth in claim 12, wherein said pixel generating unit performs pixel interpolation on a left area and a right area containing a pixel at the center, the matching position of which has been specified by pattern matching based on said left area and said right area.

16. An image processing apparatus, as set forth in claim 12, wherein said pixel generating unit performs pixel interpolation on a right area containing a pixel at the center, the matching position of which has been specified by pattern matching based on said left area and said right area.

17. An image processing apparatus, as set forth in claim 12 wherein, after the pixel interpolation between two transversely adjacent pixels in said left area or said right area, said pixel generating unit performs pixel interpolation between two vertically adjacent pixels relating to the position to be interpolated.

18. An image processing apparatus, as set forth in claim 12 wherein, after the pixel interpolation between two transversely adjacent pixels in said left area or said right area, said pixel generating unit performs pixel interpolation between two vertically adjacent pixels based on the average value of plural pixels surrounding the position to be interpolated.

19. An image processing apparatus, as set forth in claim 18, wherein said pixel generating unit weights the plural pixels surrounding the position to be interpolated when the average value is calculated.

20. An image processing apparatus, as set forth in claim 18, wherein said pixel generating unit performs pixel interpolation starting from the pixel position at which the number of pixels surrounding the position to be interpolated is largest, which is the target for which the average value is calculated.

21. An image processing apparatus, as set forth in claim 18, wherein said pixel generating unit calculates the average value after giving weight of a value less than 1 to the already interpolated pixels among the plural pixels surrounding the position to be interpolated.

22. An image processing apparatus, as set forth in claim 18, wherein said pixel generating unit performs pixel interpolation based on two pixels adjacent to each other only in the transverse direction in said left area and said right area.