Pattern-matching processing method and image processing apparatus

• US 7,386,192 B2
• Filed: 07/31/2003
• Issued: 06/10/2008
• Est. Priority Date: 07/31/2002
• Status: Expired due to Fees

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Oota, Akihiro
• Primary Examiner(s): Mehta; Bhavesh M.
• Assistant Examiner(s): Strege; John B
• Application Number:
  US10/632,583
• Publication Number:
  US 20040022418A1
• Time in Patent Office: 1,776 Days
• Field of Search: 382/106, 382/154, 382/300
• US Class Current: 382/300
• 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 interpolating step for generating an interpolation pixel between pixels of a plurality of pixels included respectively in the left area and the right area, wherein the pixel interpolating step includes performing a first pixel interpolation between two first adjacent pixels along a first direction in the left area and in the right area, and performing a second pixel interpolation between two second adjacent pixels along a second direction perpendicular to the first direction, wherein the second pixel interpolation includes calculating an average value of plural pixels surrounding a position to be interpolated, wherein the plural pixels include both interpolated pixels and non-interpolated pixels, and wherein in calculating the average value, the interpolated pixels among the plural pixels surrounding the position to be interpolated are assigned a weight less than the weight given to the non-interpolated pixels; and

a pattern matching step for performing pattern matching using the left area interpolated with the corresponding interpolation pixels and the right area interpolated with the corresponding interpolation pixels.

2. A pattern-matching processing method, as set forth in claim 1, wherein said first and second pixel interpolations are performed on said left area and said right area containing a number of pixels surrounding a matching position specified by the pattern matching step based on an original left area and an original right area.

5. A pattern-matching processing method, as set forth in claim 1, wherein said second pixel interpolation is performed starting from a pixel position at which a number of the pixels surrounding the position to be interpolated is largest, for which the average value is calculated.

3. 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 interpolating step for generating an interpolation pixel between pixels of a plurality of pixels included in either the left area or the right area, wherein the pixel interpolating step includes performing a first pixel interpolation between two first adjacent pixels along a first direction in the left area or in the right area, and performing a second pixel interpolation between two adjacent pixels along a second direction perpendicular to the first direction, wherein the second pixel interpolation includes calculating an average value of plural pixels surrounding a position to be interpolated, wherein the plural pixels include both interpolated pixels and non-interpolated pixels, and wherein in calculating the average value, the interpolated pixels among the plural pixels surrounding the position to be interpolated are assigned a weight less than the weight given to the non-interpolated pixels; and

a pattern matching step for performing pattern matching using the area interpolated with the corresponding interpolation pixel and the area without interpolation pixels.

4. A pattern-matching processing method, as set forth in claim 3, wherein said first and second interpolations are performed on said left area and said right area containing a number of pixels surrounding a matching position specified by the pattern matching step based on an original left area and an original right area.

10. A pattern-matching processing method, as set of forth in claim 3 or 4, wherein said second pixel interpolation is performed starting from a pixel position at which a number of the pixels surrounding a position to be interpolated is largest, for which the average value is calculated.

6. An image processing apparatus measuring a 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, comprising:

an area generating unit for generating a left area and a right area each having a fixed range from the left image;

a pixel interpolating unit for generating an interpolation pixel between pixels of a plurality of pixels included respectively in the left area and the right area, wherein the pixel interpolating step includes performing a first pixel interpolation between two first adjacent pixels along a first direction in the left area and in the right area, and performing a second pixel interpolation between two second adjacent pixels along a second direction perpendicular to the first direction, wherein the second pixel interpolation includes calculating an average value of plural pixels surrounding a position to be interpolated, wherein the plural pixels include both interpolated pixels and non-interpolated pixels, and wherein in calculating the average values, the interpolated pixels among the plural pixels surrounding the position to be interpolated are assigned a weight less than the weight given to the non-interpolated pixels; and

a pattern-matching processing unit having a pattern-matching unit performing pattern matching based on the left area interpolated with the corresponding interpolation pixels and the right area interpolated with the corresponding interpolation pixels, or based on one of the areas without pixel interpolation and the other area interpolated with the corresponding interpolation pixels.

7. An image processing apparatus, as set forth in claim 6, wherein said pixel interpolating unit performs pixel interpolation on the left area and the right area containing a number of pixels surrounding a matching position specified by the pattern matching step based on an original left area and an original right area.

8. An image processing apparatus, as set forth in claim 6, wherein said pixel interpolating unit performs pixel interpolation on the right area containing a number of pixels surrounding a matching position specified by the pattern matching step based on an original left area and an original right area.

9. An image processing apparatus, as set forth in claim 6, wherein said pixel interpolating unit performs pixel interpolation starting from a pixel position at which a number of the pixels surrounding the position to be interpolated is largest, for which the average value is calculated.

11. An image processing apparatus measuring a 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, comprising;

an area generating unit for generating a left area and a right area each having a fixed range from the left image;

a pixel interpolating unit for generating an interpolation pixel between pixels of a plurality of pixels included in respectively the left area and the right area, wherein the pixel interpolating step includes performing first pixel interpolation between two first adjacent pixels along a first direction in the left area and in the right area, and performing a second pixel interpolation between two second adjacent pixels along a second direction perpendicular to the first direction, wherein the second pixel interpolation includes calculating an average value of plural pixels surrounding a position to be interpolated, wherein the plural pixels include both interpolated pixels and non-interpolated pixels, and wherein in calculating the average value, the already interpolated pixels among the plural pixels surrounding the position to be interpolated are assigned a weight less than the weight given to the non-interpolated pixels; and

a pattern-matching processing unit having a pattern-matching unit performing pattern matching based on the left area interpolated with the corresponding interpolation pixels and the right area interpolated with the corresponding interpolation pixels, or based on one of the areas without pixel interpolation and the other area interpolated with the corresponding interpolation pixels; and

a distance measuring unit for calculating the distance from the difference in positions of the left image and the right image based on a matching position specified by performing pattern matching on the left area and the right area.