Object extraction method, and image sensing apparatus using the method

• US 6,993,184 B2
• Filed: 10/06/2003
• Issued: 01/31/2006
• Est. Priority Date: 11/01/1995
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Matsugu, Masakazu
• Primary Examiner(s): Ahmed, Samir
• Assistant Examiner(s): LE, BRIAN Q
• Application Number:
  US10/678,255
• Publication Number:
  US 20040066970A1
• Time in Patent Office: 848 Days
• Field of Search: 382164-165, 382170-171, 382/205, 382/209, 382217-220, 382/274, 382282- 83, 382/284, 382/312, 382215-216, 382/199, 348/231.3, 348/231.6, 348/129, 348/161, 348/225, 348/345, 348/352, 348/364, 348/365, 348/366, 348/370, 358/464, 358/453, 345/433, 345/434, 345/523
• US Class Current: 382/173
• CPC Class Codes: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60

Abstract

This invention provides an object extraction method for performing processing for extracting and cutting out a specific object from a sensed image at high speed, and an image sensing apparatus using the method. In this invention, in a method of extracting an object by comparing a sensed image and a standard image, a focusing signal, focal length data, visual axis direction data, and illumination conditions are detected, and the initial size, initial position, or initial color of the standard image is changed on the basis of the detection results, and extraction is started under optimal conditions. In a method of extracting a specific object from the background image, the background image is converted into an image having the same conditions as those of the object image. From a plurality of images obtained under different image sensing conditions, the contour of the object is accurately obtained at high speed. In an object extraction method using a template, the size of the template is determined on the basis of the object distance, object size, or the like.

Claims

1. An image extraction apparatus comprising:

image sensing means for sensing a plurality of images;

image sensing condition control means for controlling an image sensing condition when said image sensing means senses images;

image sensing condition recording/reproduction means for recording the image sensing condition when said image sensing means senses images, and reproducing and outputting the recorded image sensing condition;

image recording means for recording the plurality of images sensed by said image sensing means;

image data conversion means for converting image data of at least one of the plurality of images on the basis of the image sensing condition supplied from said image sensing condition recording/reproduction means;

image data comparison means for comparing the image data of the plurality of images converted by said image data conversion means; and

image cutting means for extracting an image in a specific image region on the basis of a comparison result output from said image data comparison means.

2. The apparatus according to claim 1, wherein said image recording means temporarily stores a background image and an image including an object, in which an image to be cut out is present in a background, and said image data comparison means extracts difference image data of the plurality of images reproduced and output from said image recording means.

3. The apparatus according to claim 2, wherein said image sensing condition recording/reproduction means records an image sensing condition when an image to be cut out in a predetermined background is sensed, and said image data conversion means converts image data of the background image on the basis of the image sensing condition reproduced and output from said image sensing condition recording/reproduction means.

4. The apparatus according to claim 3, wherein said image recording means encodes and records the image data in the specific image region obtained by said image cutting means.

5. The apparatus according to claim 4, wherein said image data conversion means performs a space shift operation to maximize similarity between the background image and the image including the object.

6. The apparatus according to claim 4, wherein the image sensing condition includes an exposure amount, a focusing state, and the presence/absence of flash emission.

7. The apparatus according to claim 4, wherein said image data conversion means converts an image size, luminance level, color component, and resolution.

8. The apparatus according to claim 3, wherein said image data conversion means performs a space shift operation to maximize similarity between the background image and the image including the object.

9. The apparatus according to claim 3, wherein the image sensing condition includes an exposure amount, a focusing state, and the presence/absence of flash emission.

10. The apparatus according to claim 3, wherein said image data conversion means converts an image size, luminance level, color component, and resolution.

11. The apparatus according to claim 2, wherein said image recording means encodes and records the image data in the specific image region obtained by said image cutting means.

12. The apparatus according to claim 11, wherein said image data conversion means performs a space shift operation to maximize similarity between the background image and the image including the object.

13. The apparatus according to claim 11, wherein the image sensing condition includes an exposure amount, a focusing state, and the presence/absence of flash emission.

14. The apparatus according to claim 11, wherein said image data conversion means converts an image size, luminance level, color component, and resolution.

15. The apparatus according to claim 2, wherein said image data conversion means performs a space shift operation to maximize similarity between the background image and the image including the object.

16. The apparatus according to claim 2, wherein the image sensing condition includes an exposure amount, a focusing state, and the presence/absence of flash emission.

17. The apparatus according to claim 2, wherein said image data conversion means converts an image size, luminance level, color component, and resolution.

18. The apparatus according to claim 1, wherein said image recording means encodes and records the image data in the specific image region obtained by said image cutting means.

19. The apparatus according to claim 18, wherein said image data conversion means performs a space shift operation to maximize similarity between the background image and the image including the object.

20. The apparatus according to claim 18, wherein the image sensing condition includes an exposure amount, a focusing state, and the presence/absence of flash emission.

21. The apparatus according to claim 18, wherein said image data conversion means converts an image size, luminance level, color component, and resolution.

22. The apparatus according to claim 1, wherein said image data conversion means performs a space shift operation to maximize similarity between the background image and the image including the object.

23. The apparatus according to claim 1, wherein the image sensing condition includes an exposure amount, a focusing state, and the presence/absence of flash emission.

24. The apparatus according to claim 1, wherein said image data conversion means converts an image size, luminance level, color component, and resolution.