Image processing method and apparatus for recognizing an arrangement of an object

• US 5,987,162 A
• Filed: 09/27/1996
• Issued: 11/16/1999
• Est. Priority Date: 03/27/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Nakata, Masafumi
• Primary Examiner(s): Lee, Thomas D.
• Assistant Examiner(s): Chen, Wenpeng
• Application Number:
  US08/722,643
• Time in Patent Office: 1,145 Days
• Field of Search: 382/152, 382/216, 382/289, 382/136, 382/151, 382/287, 382/141, 382/144, 382/209, 382/203, 382/291, 382/294, 382/293, 382/296, 358/488, 395/105
• US Class Current: 382/152
• CPC Class Codes: G06T 3/60 Rotation of whole images or parts thereof
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80

Abstract

An image processing method includes the steps of setting a predetermined concentric circular area of first and second image data as a workpiece image, dividing a plurality of pixels constituting the workpiece image in the concentric circular area into a concentric circuit arrangement and extracting the plurality of pixels, generating the plurality of pixels in the divided concentric circuit arrangement as a function of the central angular position of the concentric circle, computing the initial term resulting from subjecting the luminance of the plurality of pixels in the concentric circular arrangement to Fourier expansion together with the central angular position, computing the central angular position where the initial term of Fourier expansion is maximized as a function of a plurality of concentric radii, and comparing the function with the first and second image data so as to recognize the arrangement of an object to be detected.

Claims

1. An image processing apparatus for recognizing an arrangement of an object to be detected by comparing first image data obtained through imaging said object to be detected with pre-cataloged second image data concerning said object, said apparatus comprising:

workpiece image data cataloging means for setting a predetermined concentrically-shaped area of said first and second image data as a workpiece image, said concentrically-shaped area being of sufficient size to include the exterior edge the object;

luminance graph generating means for dividing into a concentric arrangement a plurality of pixels constituting the image data in the concentrically-shaped area set by said image data cataloging means and extracting the plurality of pixels so as to generate the luminance of the plurality of pixels thus divided into the concentric arrangement as a function of a central angular position with respect to said concentrically-shaped area;

characteristic value computing means for computing a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels generated by said luminance graph generating means together with the central angular position; and

central angular position pattern computing means for computing the central angular position living said characteristics of luminance computed by said characteristic value computing means as a function of the distance from the center of the plurality of the divided concentrically-arranged positions;

wherein the arrangement of said object is recognized by comparing said first and second image data with the relation between the central angular position giving said characteristics of luminance concerning the concentrically-arranged positions computed by said central angular position pattern computing means, and the distance from the center of the plurality of the divided concentrically-arranged positions; and

wherein said characteristic value computing means makes it a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels that the initial term of Fourier series is a maximum value, the initial term thereof being obtained by subjecting to Fourier expansion the luminance of the plurality of concentrically-arranged pixels as a function of the central angular position generated by said luminance graph generating means in terms of the central angular position.

4. An image processing apparatus as claimed in claim 1, wherein said luminance graph generating means extracts the plurality of concentrically-arranged pixels by thinning out the pixels at a predetermined thinning ratio and generates the luminance of the plurality of concentrically-arranged pixels thus extracted as a function of the concentrically-shaped central angular position.

5. An image processing apparatus as claimed in claim 1, wherein said characteristic value computing means makes a non-zero value a character representing the characteristics of the luminance, the non-zero value being selected from among values of the initial term of said Fourier series.

6. An image processing apparatus as claimed in claim 1, wherein when values of the initial term of said Fourier series are totally zero, said characteristic value computing means decides that said object has such a shape that its inclination from the reference line is unspecifiable.

2. An image processing apparatus for recognizing an arrangement of an object to be detected by comparing first image data obtained through imaging said object to be detected with pre-catalyzed second image data concerning said object, said apparatus comprising:

workpiece image data cataloging means for setting a predetermined concentrically-shaped area of said first and second image data as a workpiece image, said concentrically-shaped area being of sufficient size to include the exterior edge the object;

luminance graph generating means for dividing into a concentric arrangement a plurality of pixels constituting the image data in the concentrically-shaped area set by said image data cataloging means and extracting the plurality of pixels so as to generate the luminance of the plurality of pixels thus divided into the concentric arrangement as a function of a central angular position with respect to said concentrically-shaped area;

characteristic value computing means for computing a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels generated by said luminance graph generating means together with the central angular position; and

central annular position pattern computing means for computing the central angular position giving said characteristics of luminance computed by said characteristic value computing means as a function of the distance from the center of the plurality of the divided concentrically-arranged positions;

wherein the arrangement of said object is recognized by comparing said first and second image data with the relation between the central angular position giving said characteristics of luminance concerning the concentrically-arranged positions computed by said central angular position pattern computing means, and the distance from the center of the plurality of the divided concentrically-arranged positions; and

wherein said characteristic value computing means makes it a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels that the center of gravity is concerned with the central angular position of the luminance as a function of the central angular position generated by said luminance graph generating means.

3. An image processing apparatus for recognizing an arrangement of an object to be detected by comparing first image data obtained through imaging said object to be detected with pre-cataloged second image data concerning said object, said apparatus comprising:

workpiece image data cataloging means for setting a predetermined concentrically-shaped area of said first and second image data as a workpiece image, said concentrically-shaped area being of sufficient size to include the exterior edge the object;

luminance graph generating means for dividing into a concentric arrangement a plurality of pixels constituting the image data in the concentrically-shaped area set by said image data cataloging means and extracting the plurality of pixels so as to generate the luminance of the plurality of pixels thus divided into the concentric arrangement as a function of a central angular position with respect to said concentrically-shaped area;

characteristic value computing means for computing a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels generated by said luminance graph generating means together with the central angular position; and

central angular position pattern computing means for computing the central angular position giving said characteristics of luminance computed by said characteristic value computing means as a function of the distance from the center of the plurality of the divided concentrically-arranged positions;

wherein the arrangement of said object is recognized by comparing said first and second image data with the relation between the central angular position giving said characteristics of luminance concerning the concentrically-arranged positions computed by said central angular position pattern computing means, and the distance from the center of the plurality of the divided concentrically-arranged positions; and

wherein said characteristic value computing means makes it a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels that the luminance with respect to the central angular position of the luminance as a function of the central angular position generated by said luminance graph generating means is maximized.

7. An image processing method for recognizing an arrangement of an object to be detected by comparing first image data obtained through imaging said object with pre-cataloged second data concerning said object therefor, said method comprising the steps of:

setting a predetermined concentrically-shaped area of said first and second image data as a workpiece image, said concentrically-shaped area being of sufficient size to include the exterior edge the object;

dividing into a concentric arrangement a plurality of pixels constituting the image data in the concentrically-shaped area and extracting the plurality of pixels so as to generate the luminance of the plurality of pixels thus divided into the concentric arrangement as a function of a central angular position with respect to said concentrically-shaped area;

computing a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels to ether with the central angular position;

computing the central angular position giving said characteristics of luminance as a function of the distance from the center of the plurality of the divided concentrically-arranged positions; and

comparing said first and second image data with the relation between the central angular position giving said characteristics of luminance concerning the concentrically-arranged positions and the distance from the center of the plurality of the divided concentrically-arranged positions so as to recognize the arrangement of said object;

wherein a character representing the characteristics of the luminance of the plurality of concentrically-arranged pixels features that the initial term of Fourier series is a maximum value, the initial term thereof being obtained by subjecting to Fourier expansion the luminance of the plurality of concentrically-arranged pixels as a function of the central angular position generated in terms of the central angular position.