Image processing apparatus

• US 6,647,146 B1
• Filed: 08/05/1998
• Issued: 11/11/2003
• Est. Priority Date: 08/05/1997
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Haslam, Jane, Lyons, Alexander Ralph, Davison, Allan Joseph, Taylor, Richard Ian, Rowe, Simon Michael
• Primary Examiner(s): Grant, II, Jerome
• Application Number:
  US09/129,080
• Time in Patent Office: 1,924 Days
• Field of Search: 382/48, 382/30, 382/294, 382/190, 382/192, 382/193, 382/202, 382/199, 382/266
• US Class Current: 382/199
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G06T 7/564 from contours

Abstract

In an apparatus and method for creating a three-dimensional model of an object, images of the object taken from different, unknown positions are processed to identify the points in the images which correspond to the same point on the actual object (that is “matching” points), the matching points are used to determine the relative positions from which the images were taken, and the matching points and calculated positions are used to calculate points in a three-dimensional space representing points on the object. A number of different techniques are used to identify the matching points, and a number of solutions are calculated and tested for the relative positions. Edges in an image are identified by first identifying corner points in the image and then identifying edges between the corner points on the basis of edge orientation values of pixels, the edges are processed in strength order to remove cross-overs, the images sub-divided into regions by connecting points at the ends of the edges on the basis of the edge strengths, and matching points within corresponding regions in two or more images are identified.

Claims

1. In an image processing apparatus having a processor for processing first input signals defining an image of an object and second input signals defining a plurality of points in the image, a method of processing the input signals to produce signals defining segments of the image, the method comprising:

determining whether an edge exists between each pair of points, together with an edge strength for each edge identified; and

connecting the points in dependence upon the edge strengths to form triangles, with any three points which have therebetween two edges each of which has a strength greater than a predetermined threshold being connected to form a triangle.

2. A method according to claim 1, wherein connections are made between the other points in order of increasing connection length.

3. A method according to claim 1, wherein the points defined by the second input signals comprise points matched with points in another image.

4. A method according to claim 1, wherein the points defined by the second input signals comprise corner points.

5. In an image processing apparatus having a processor for processing input signals defining first and second images of an object, a method of processing the input signals to produce signals defining segments of at least one of the images, the method comprising:

processing the input signals to identify matching points in the images;

determining a strength of any edges between identified points in at least one of the images; and

connecting the points in at least one of the images in dependence upon the edge strengths.

6. A method according to claim 5, wherein a strength of any edges between identified points in the first image is determined, a strength of any edges between identified points in the second image is determined, a combined strength measure is calculated for corresponding edges in the first and second images and the points in the at least one image are connected in dependence upon the combined strength measure.

7. A method according to claim 6, wherein the combined strength measure for corresponding edges is determined by calculating a mean of the strength of the edge in the first image and the strength of the corresponding edge in the second image.

8. In an image processing apparatus having a processor for processing first input signals defining an image of an object and second input signals defining a plurality of points in the image, a method of processing the input signals comprising:

determining whether an edge exists between each pair of points, together with an edge strength for each edge identified;

connecting the points in dependence upon the edge strengths to define segments of the image;

processing the segments to generate image data; and

displaying an image using the generated image data.

9. A method according to claim 8, wherein the generated image data comprises compressed image data.

10. An image processing apparatus for processing first input signals defining an image of an object and second input signals defining a plurality of points in the image, to produce signals defining segments of the image, comprising:

an edge processor for determining whether an edge exists between each pair of points, together with an edge strength for each edge identified; and

an image segmenter for connecting the points in dependence upon the edge strengths to form triangles, with any three points which have therebetween two edges each of which has a strength greater than a predetermined threshold being connected to form a triangle.

11. Apparatus according to claim 10, wherein the image segmenter is arranged to make connections between other points in order of increasing connection length.

12. Apparatus according to claim 10, wherein the points defined by the second input signals comprise points matched with points in another image.

13. Apparatus according to claim 10, wherein the points defined by the second input signals comprise corner points.

14. An image processing apparatus for processing input signals defining first and second images of an object to produce signals defining segments of at least one of the images, the apparatus comprising:

a point matcher for processing the input signals to identify matching points in the images;

a strength calculator for determining a strength of any edges between identified points in at least one of the images; and

an image segmenter for connecting the points in at least one of the images in dependence upon the edge strengths.

15. Apparatus according to claim 14, wherein the apparatus is arranged to determine a strength of any edges between identified points in the first image, to determine a strength of any edges between identified points in the second image, to calculate a combined strength measure for corresponding edges in the first and second images and to connect the points in the at least one image in dependence upon the combined strength measure.

16. Apparatus according to claim 15, wherein the apparatus is arranged to determine the combined strength measure for corresponding edges by calculating a mean of the strength of the edge in the first image and the strength of the corresponding edge in the second image.

17. An image processing apparatus for processing first input signals defining an image of an object and second input signals defining a plurality of points in the image, the apparatus comprising:

an edge processor for determining whether an edge exists between each pair of points, together with an edge strength for each edge identified;

an image segmenter for connecting the points in dependence upon the edge strengths to define segments of the image;

an image data generator to generate image data by processing the segments; and

a display to display an image using the generated image data.

18. Apparatus according to claim 17, wherein the generated image data comprises compressed image data.

19. An image processing apparatus for processing first input signals defining an image of an object and second input signals defining a plurality of points in the image, to produce signals defining segments of the image, comprising:

means for determining whether an edge exists between each pair of points, together with an edge strength for each edge identified; and

means for connecting the points in dependence upon the edge strengths to form triangles, with any three points which have therebetween two edges each of which has a strength greater than a predetermined threshold being connected to form a triangle.

20. An image processing apparatus for processing input signals defining first and second images of an object to produce signals defining segments of at least one of the images, the apparatus comprising:

means for processing the input signals to identify matching points in the images;

means for determining a strength of any edges between identified points in at least one of the images; and

means for connecting the points in at least one of the images in dependence upon the edge strengths.

21. An image processing apparatus for processing first input signals defining an image of an object and second input signals defining a plurality of points in the image, the apparatus comprising:

means for determining whether an edge exists between each pair of points, together with an edge strength for each edge identified;

means for connecting the points in dependence upon the edge strengths to define segments of the image;

means for generating image data by processing the segments; and

means for displaying an image using the generated image data.

22. A storage medium storing computer program instructions for programming a programmable processing apparatus to become operable to process first input signals defining an image of an object and second input signals defining a plurality of points in the image, to produce signals defining segments of the image, the instructions comprising instructions for programming the programmable processing apparatus to become operable to:

determine whether an edge exists between each pair of points, together with an edge strength for each edge identified; and

connect the points in dependence upon the edge strengths to form triangles, with any three points which have therebetween two edges each of which has a strength greater than a predetermined threshold being connected to form a triangle.

23. A storage medium storing computer program instructions for programming a programmable processing apparatus to become operable to process input signals defining first and second images of an object, to produce signals defining segments of at least one of the images, the instructions comprising instructions for programming the programmable processing apparatus to become operable to:

process the input signals to identify matching points in the images;

determine a strength of any edges between identified points in at least one of the images; and

connect the points in at least one of the images in dependence upon the edge strengths.

24. A storage medium storing computer program instructions for programming a programmable processing apparatus to become operable to process first input signals defining an image of an object and second input signals defining a plurality of points in the image, the instructions comprising instructions for programming the programmable processing apparatus to become operable to:

determine whether an edge exists between each pair of points, together with an edge strength for each edge identified;

connect the points in dependence upon the edge strengths to define segments of the image;

process the segments to generate image data; and

display an image using the generated image data.

25. A signal carrying computer program instructions for programming a programmable processing apparatus to become operable to process first input signals defining an image of an object and second input signals defining a plurality of points in the image, to produce signals defining segments of the image, the instructions comprising instructions for programming the programmable processing apparatus to become operable to:

determine whether an edge exists between each pair of points, together with an edge strength for each edge identified; and

connect the points in dependence upon the edge strengths to form triangles, with any three points which have therebetween two edges each of which has a strength greater than a predetermined threshold being connected to form a triangle.

26. A storage medium storing computer program instructions for programming a programmable processing apparatus to become operable to process input signals defining first and second images of an object, to produce signals defining segments of at least one of the images, the instructions comprising instructions for programming the programmable processing apparatus to become operable to:

process the input signals to identify matching points in the images;

determine a strength of any edges between identified points in at least one of the images; and

connect the points in at least one of the images in dependence upon the edge strengths.

27. A storage medium storing computer program instructions for programming a programmable processing apparatus to become operable to process first input signals defining an image of an object and second input signals defining a plurality of points in the image, the instructions comprising instructions for programming the programmable processing apparatus to become operable to:

determine whether an edge exists between each pair of points, together with an edge strength for each edge identified;

connect the points in dependence upon the edge strengths to define segments of the image;

process the segments to generate image data; and

display an image using the generated image data.