Method, apparatus, computer program, computer system, and computer-readable storage medium for representing and searching for an object in an image

• US 7,356,203 B2
• Filed: 11/08/2006
• Issued: 04/08/2008
• Est. Priority Date: 07/05/1999
• Status: Expired due to Term

• Current Assignee: Rakuten Group, Inc.
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Bober, Miroslaw Z.
• Primary Examiner(s): MARIAM, DANIEL G
• Application Number:
  US11/557,836
• Publication Number:
  US 20070065016A1
• Time in Patent Office: 517 Days
• Field of Search: 382/103, 382/181, 382/190, 382/199, 382/266, 382/268, 382/305, 382/316, 358/3.27, 358/403
• US Class Current: 382/305
• CPC Class Codes: G06F 16/5854 using shape and object relationship
• CPC Class Codes: G06V 10/46 Descriptors for shape, contour or point-related descriptors, e.g. scale invariant feature transform [SIFT] or bags of words [BoW]; Salient regional features colour feature extraction G06V10/56
• CPC Class Codes: G06V 10/752 Contour matching

Abstract

A method of representing an object appearing in a still or video image, by processing signals corresponding to the image, comprises deriving a plurality of numerical values associated with features appearing on the outline of an object starting from an arbitrary point on the outline and applying a predetermined ordering to said values to arrive at a representative of the outline.

Claims

1. A method of representing an object appearing in an image or a sequence of images, by processing signals corresponding to the image or images, the method comprising deriving a curvature scale space (CSS) representation of an original outline of an object starting from an arbitrary point on the outline, by smoothing the outline in a plurality of stages using a smoothing parameter, resulting in a plurality of outline curves, using values for points of inflection of each outline curve to derive characteristic curves which are characteristic of the original outline, and selecting the co-ordinates of peaks of said characteristic curves, the method further comprising ordering the co-ordinate values of the CSS representation by placing the co-ordinate values with the highest peak co-ordinate value, corresponding the smoothing parameter, first.

2. A method as claimed in claim 1, wherein the peak co-ordinate values are ordered on the basis of the peak height values, corresponding to the smoothing parameter.

3. A method as claimed in claim 2, wherein the values are ordered in decreasing size.

4. A method of searching for an object in a still or video image by processing signals corresponding to images, the method comprising inputting a query in the form of a two-dimensional outline, deriving a descriptor of said outline using a method as claimed in claim 1, obtaining a descriptor of objects in stored images derived using a method as claimed in claim 1 and comparing said query descriptor with each descriptor for a stored object, and selecting and displaying at least one result corresponding to an image containing an object for which the comparison indicates a degree of similarity between the query and said object.

5. An apparatus configured to implement a method as claimed in claim 4.

6. A computer system programmed to operate according to a method as claimed in claim 4.

7. A computer-readable storage medium storing computer-executable process steps for implementing a method as claimed in claim 4.

8. A method as claimed in claim 4 wherein the step of obtaining a descriptor of objects in stored images comprises forming an object descriptor from the ordered co-ordinate values of the CSS representation with the co-ordinate values with the highest peak co-ordinate value first.

9. A method as claimed in claim 8 wherein the object descriptor has the highest peak co-ordinate value first, irrespective of orientation of the original outline of the object.

10. An apparatus configured to implement a method as claimed in claim 1.

11. A computer system programmed to operate according to a method as claimed in claim 1.

12. A computer-readable storage medium storing computer-executable process steps for implementing a method as claimed in claim 1.

13. A method as claimed in claim 1 further comprising an object descriptor from the ordered co-ordinate values of the CSS representation with the co-ordinate values with the highest peak co-ordinate value first.

14. A method as claimed in claim 13 wherein the object descriptor has the highest peak co-ordinate value first, irrespective of orientation of the original outline of the object.

15. A method as claimed in claim 13 wherein the object descriptor is used or usable for searching or matching.