Device, method, and computer-readable medium for detecting changes in objects in images and their features

• US 20020051572A1
• Filed: 10/31/2001
• Published: 05/02/2002
• Est. Priority Date: 10/31/2000
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ida, Takashi, Matsumoto, Nobuyuki
• Application Number:
  US09/984,688
• Publication Number:
  US 20020051572A1
• Time in Patent Office: Days
• US Class Current: 382/190
• CPC Class Codes: G06T 2207/20164 Salient point detection; Corner detection
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/174 involving the use of two or more images
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: G06V 10/44 Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components
• CPC Class Codes: G06V 10/752 Contour matching

Abstract

A feature pattern (e.g., contours of an object) of an input image to be processed is extracted. A feature pattern (e.g., contours of an object) of a reference image corresponding to the input image is extracted. A comparison is made between the extracted feature patterns of the input and reference images. Their difference is output as the result of the comparison.

Claims

1. An image processing method comprising:

extracting a feature pattern from an input image that depicts an object;

extracting a feature pattern from a reference image corresponding to the input image, the reference image being generated in advance of the input image; and

comparing the extracted feature pattern of the input image and the extracted feature pattern of the reference image to detect a change in the object.

3. The image processing method according to claim 1, wherein at least one of contours and corners of the object in the input and reference images is extracted as the feature pattern.

2. An image processing method comprising:

extracting a feature pattern from an input image that depicts an object;

extracting a feature pattern from a reference image corresponding to the input image, the reference image being generated in advance of the input image;

computing the relative displacement of the extracted feature pattern of the input image and the extracted feature pattern of the reference image;

correcting the relative position of the extracted feature pattern of the input image and the extracted feature pattern of the reference image on the basis of the computed displacement; and

comparing the extracted feature pattern of the input image and the extracted feature pattern of the reference image after the relative position has been corrected to detect a change in the object.

4. An image processing method comprising:

extracting a first feature pattern and a second feature pattern from an input image that depicts an object;

extracting a third feature pattern and a fourth feature pattern from a reference image corresponding to the input image, the reference image being generated in advance of the input image;

computing the relative displacement of the extracted first feature pattern of the input image and the extracted third feature pattern of the reference image;

correcting the relative position of the extracted second feature pattern of the input image and the extracted fourth feature pattern of the reference image on the basis of the computed displacement; and

comparing the extracted second feature pattern of the input image and the extracted fourth feature pattern of the reference image after the relative position has been corrected to detect a change in the object.

5. An image processing device comprising:

a first feature pattern extraction device configured to extract a feature pattern from an input image that depicts an object;

a second feature pattern extraction device configured to extract a feature pattern from a reference image corresponding to the input image, the reference image being generated in advance of the input image; and

a comparing device configured to compare the extracted feature pattern of the input image and the extracted feature pattern of the reference image to detect a change in the object.

6. An image processing device comprising:

a feature pattern extraction device configured to extract a feature pattern from an input image that depicts an object;

a storage to store a feature pattern extracted from a reference image corresponding to the input image, the reference image being generated in advance of the input image; and

a comparing device configured to compare the extracted feature pattern of the input image and the stored feature pattern of the reference image.

7. A method of detecting one point from a set of points forming the shape of an object included in an input image to be processed as a feature point representing the feature of the shape, comprising:

placing a rectangular region of interest containing at least one portion of the object onto the input image;

searching for a similar region which is in a similarity relationship with the rectangular region of interest through operations using image data from at least one portion of the object;

calculating a map from the similar region to the rectangular region of interest or the rectangular region of interest to the similar region; and

detecting a fixed point in the map as the feature point.

8. The method according to claim 7, wherein the similar region is identical in aspect ratio to the rectangular region of interest.

9. The method according to claim 7, wherein the similar region is different in aspect ratio from the rectangular region of interest.

10. The method according to claim 7, wherein the similar region is larger in width and smaller in height than the rectangular region of interest.

11. The method according to claim 7, wherein the similar region is smaller in width and larger in height than the rectangular region of interest.

12. The method according to claim 7, wherein the similar region includes an oblique rectangle.

13. The method according to claim 7, wherein the similar region is tilted relative to the rectangular region of interest.

14. The method according to claim 7, wherein the similar region is tilted relative to and the same size as the rectangular region of interest.

15. The method according to claim 7, wherein the similar region is equal in height to and different in width from the rectangular region of interest.

16. A position specification supporting method used in specifying a feature point representing the feature of the shape of an object in an input image to be processed through the use of position specifying device, comprising:

specifying a point in the vicinity of the feature point through the use of the position specifying device;

placing a rectangular region of interest containing at least one portion of the object with the point specified by the position specifying device as the center;

searching for a similar region which is in a similarity relationship with the rectangular region of interest through operations using image data from the at least one portion of the object;

calculating a map from the similar region to the rectangular region of interest or the rectangular region of interest to the similar region;

detecting a fixed point in the map as the feature point; and

shifting the specified point to the position of the detected feature point.

17. A computer-readable medium having a computer program embodied thereon, the computer program comprising:

a code segment that extracts a feature pattern from an input image that depicts an object;

a code segment that extracts a feature pattern from a reference image corresponding to the input image, the reference image being generated in advance of the input image; and

a code segment that compares the extracted feature pattern of the input image and the extracted feature pattern of the reference image to detect a change in the object.

18. A computer-readable medium having a computer program embodied thereon, the computer program comprising:

a code segment that extracts a feature pattern from an input image that depicts an object;

a code segment that extracts a feature pattern from a reference image corresponding to the input image, the reference image being generated in advance of the input image;

a code segment that computes the relative displacement of the extracted feature pattern of the input image and the extracted feature pattern of the reference image;

a code segment that corrects the relative position of the extracted feature pattern of the input image and the extracted feature pattern of the reference image on the basis of the computed displacement; and

a code segment that compares the extracted feature pattern of the input image and the extracted feature pattern of the reference image after the relative position has been corrected to detect a change in the object.

19. A computer-readable medium having a computer program embodied thereon for causing a point in a set of points forming the shape of an object to be detected as a feature point representing the feature of the shape of the object from an input image to be processed, the computer program comprising:

a code segment that places a rectangular region of interest containing at least one portion of the object onto the input image;

a code segment that searches for a similar region which is in a similarity relationship with the rectangular region of interest through operations using image data from at least one portion of the object;

a code segment that calculates a map from the similar region to the rectangular region of interest or the rectangular region of interest to the similar region; and

a code segment that detects a fixed point in the map as the feature point.

20. A computer-readable medium having a computer program embodied thereon, the computer program being used in specifying a feature point representing the feature of the shape of an object in an input image to be processed through the use of a position specifying device and comprising:

a code segment that places a rectangular region of interest containing at least one portion of the object with a point specified by the position specifying device as the center;

a code segment that searches for a similar region which is in a similarity relationship with the rectangular region of interest through operations using image data from the at least one portion of the object;

a code segment that calculates a map from the similar region to the rectangular region of interest or the rectangular region of interest to the similar region;

a code segment that detects a fixed point in the map as the feature point; and

a code segment that shifts the specified point to the position of the detected feature point.