Photographing apparatus and method for controlling target tracking

• US 20080101655A1
• Filed: 06/04/2007
• Published: 05/01/2008
• Est. Priority Date: 10/25/2006
• Status: Active Grant

• Current Assignee: Hanwha Vision Company Limited (Hanwha Corporation)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Seo, Jin-keun, Lee, Suk-ho, Woo, Hyun-gun, Noh, Seung-in
• Granted Patent: US 8,050,455 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06V 10/255 Detecting or recognising potential candidate objects based on visual cues, e.g. shapes
• CPC Class Codes: G06V 10/62 relating to a temporal dimension, e.g. time-based feature extraction; Pattern tracking

Abstract

A photographing apparatus and a method for controlling target tracking are provided. The photographing apparatus includes a target extractor for extracting target information in a present frame based on the difference between a pixel value of one pixel among previous pixels constituting the target of the previous frame in an area adjacent to the present pixel constituting the present frame and a pixel value of the present pixel, and a tracking controller for controlling automatic tracking for the target based on the target information. Accordingly, the target can be extracted more precisely.

Claims

1. A photographing apparatus comprising:

a target extractor for extracting target information in a present frame based on information regarding a difference between a pixel value of one pixel among previous pixels constituting the target of the previous frame in an area adjacent to the present pixel constituting the present frame and a pixel value of the present pixel; and

a tracking controller for controlling automatic tracking for the target based on the target information.

2. The photographing apparatus of claim 1, wherein the target extractor comprises a target-difference image generator for generating a target-difference image by modifying the pixel value of the present pixel to the difference between the pixel value of the present pixel and a pixel value most similar to the pixel value of the present pixel among the pixel values of the previous pixels constituting the target of the previous frame in the area adjacent to the present pixel, and

the target extractor extracts target information in the present frame based on the target-difference image.

3. The photographing apparatus of claim 2, wherein the target-difference image generator generates the target-difference image by modifying the pixel value of the target-difference image for the present pixel to a preset pixel value, if the target of the previous frame is not in the area adjacent to the present pixel.

4. The photographing apparatus of claim 2, wherein the target extractor further comprises a target-difference image divider for generating a target-segment by dividing an area from the target-difference image based on the size of the pixel values of the pixels constituting the target-difference image, and

the target extractor extracts the target information in the present frame based on the target-segment.

5. The photographing apparatus of claim 4, wherein the target-difference image divider generates the target-segment by dividing pixels comprising a pixel value less than a first pixel value from the target-difference image.

6. The photographing apparatus of claim 5, wherein the target-difference image divider regenerates the target-segment by dividing pixels comprising a pixel value less than a second pixel value from the pixels constituting the target-segment.

7. The photographing apparatus of claim 2, wherein the target extractor comprises a background-difference image generator for generating a background-difference image by modifying the pixel value of the present pixel to the difference between the pixel value of the present pixel and a pixel value most similar to the pixel value of the present pixel among the pixel values of the previous pixels constituting the background of the previous frame in the area adjacent to the present pixel, and

the target extractor extracts the target information in the present frame based on the target-difference image and the background-difference image.

8. The photographing apparatus of claim 7, wherein the target extractor further comprises:

a target-difference image divider for generating a target-segment by dividing an area from the target-difference image based on the size of the pixel values of the pixels constituting the target-difference image;

a background-difference image divider for generating a background-segment by dividing an area from the background-difference image based on the size of the pixel values of the pixels constituting the background-difference image; and

a target reconstructor for outputting the target information by excluding the pixels constituting the background-segment from the pixels constituting the target-segment.

9. A method for controlling target tracking, comprising:

extracting target information in a present frame based on a difference between a pixel value of one pixel among previous pixels constituting the target of the previous frame in an area adjacent to the present pixel constituting the present frame and a pixel value of the present pixel; and

controlling automatic tracking for the target based on the target information.

10. The method of claim 9, wherein extracting the target information comprises generating a target-difference image by modifying the pixel value of the present pixel to the difference between the pixel value of the present pixel and a pixel value most similar to the pixel value of the present pixel among the pixel values of the previous pixels constituting the target of the previous frame in the area adjacent to the present pixel, and

in extracting the target information, the target information in the present frame is extracted based on the target-difference image.

11. The method of claim 10, wherein in generating the target-difference image, the target-difference image is generated by modifying the pixel value of the target-difference image for the present pixel to a preset pixel value, if the target of the previous frame is not in the area adjacent to the present pixel.

12. The method of claim 10, wherein extracting the target information further comprises generating a target-segment by dividing an area from the target-difference image based on the size of the pixel values of the pixels constituting the target-difference image, and

in extracting the target information, the target information in the present frame is extracted based on the target-segment.

13. The method of claim 12, wherein in generating the target-segment, the target-segment is generated by dividing pixels comprising a pixel value less than a first pixel value from the target-difference image.

14. The method of claim 13, wherein in generating the target-segment, the target-segment is regenerated by dividing pixels comprising a pixel value less than a second pixel value from the pixels constituting the target-segment.

15. The method of claim 10, wherein extracting the target information comprises generating a background-difference image by modifying the pixel value of the present pixel to the difference between the pixel value of the present pixel and a pixel value most similar to the pixel value of the present pixel among the pixel values of the previous pixels constituting the background of the previous frame in the area adjacent to the present pixel, and

in extracting the target information, the target information in the present frame is extracted based on the target-difference image and the background-difference image.

16. The method of claim 15, wherein extracting the target information further comprises:

generating a target-segment by dividing an area from the target-difference image based on the size of the pixel values of the pixels constituting the target-difference image;

generating a background-segment by dividing an area from the background-difference image based on the size of the pixel values of the pixels constituting the background-difference image; and

outputting the target information by excluding the pixels constituting the background-segment from the pixels constituting the target-segment.

17. A photographing apparatus comprising:

a target extractor for extracting target information in a present frame based on a similarity between a pixel value of a pixel constituting the present frame and a pixel value of a pixel among pixels constituting a target of a previous frame; and

a tracking controller for controlling automatic tracking for the target based on the target information.

18. The photographing apparatus of claim 17, wherein the target extractor comprises a first divider for generating a target-segment by dividing an area from the present frame based on the similarity between a pixel value of a pixel constituting the present frame and a pixel value of a pixel among pixels constituting a target of a previous frame, and

the target extractor extracts the target information based on the target-segment.

19. The photographing apparatus of claim 18, wherein the target extractor further comprises a second divider for generating a background-segment by dividing another area from the present frame based on the similarity between the pixel value of the pixel constituting the present frame and the pixel value of the pixel among pixels constituting the target of the previous frame;

and

the target extractor extracts the target information based on the target-segment and the background-segment.

20. The photographing apparatus of claim 19, wherein the target extractor further comprises a target reconstructor for outputting the target information by excluding the pixels constituting the background-segment from the pixels constituting the target-segment.

21. A method for controlling target tracking, comprising:

extracting target information in a present frame based on a similarity between a pixel value of a pixel constituting the present frame and a pixel value of a pixel among pixels constituting a target of a previous frame; and

controlling automatic tracking for the target based on the target information.

22. The method of claim 21, wherein extracting the target information comprises generating a target-segment by dividing an area from the present frame based on the similarity between a pixel value of a pixel constituting the present frame and a pixel value of a pixel among pixels constituting a target of a previous frame, and

the target information is extracted based on the target-segment.

23. The method of claim 22, wherein extracting the target information further comprises generating a background-segment by dividing another area from the present frame based on the similarity between the pixel value of the pixel constituting the present frame and the pixel value of the pixel among pixels constituting the target of the previous frame;

and

the target information is extracted based on the target-segment and the background-segment.

24. The method of claim 23, wherein extracting the target information further comprises outputting the target information by excluding the pixels constituting the background-segment from the pixels constituting the target-segment.

25. A photographing apparatus comprising:

a target extractor for extracting target information in a present frame by determining a target and a background in the present frame and excluding pixels determined to be the background from pixels determined to be the target; and

a tracking controller for controlling automatic tracking for the target based on the target information.

26. A method for controlling target tracking, comprising:

extracting target information in a present frame by determining a target and a background in the present frame and excluding pixels determined to be the background from pixels determined to be the target; and

controlling automatic tracking for the target based on the target information.

27. A computer-readable medium having embodied thereon a computer program for executing the method of controlling target tracking, the method comprising:

extracting target information in a present frame based on a difference between a pixel value of one pixel among previous pixels constituting the target of the previous frame in an area adjacent to the present pixel constituting the present frame and a pixel value of the present pixel; and

controlling automatic tracking for the target based on the target information.

28. A computer-readable medium having embodied thereon a computer program for executing the method of controlling target tracking, the method comprising:

extracting target information in a present frame based on a similarity between a pixel value of a pixel constituting the present frame and a pixel value of a pixel among pixels constituting a target of a previous frame; and

controlling automatic tracking for the target based on the target information.