Apparatus for detecting a movement vector or an image by detecting a change amount of an image density value

• US 5,734,441 A
• Filed: 03/13/1995
• Issued: 03/31/1998
• Est. Priority Date: 11/30/1990
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sekine, Masayoshi, Kondo, Toshiaki
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US08/402,990
• Time in Patent Office: 1,114 Days
• Field of Search: 348/208, 348/699-701, 348/135, 348/143, 348/152, 348/169, 382/107, 382/103
• US Class Current: 348/700
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/683 performed by a processor, e.g. controlling the readout of an image memory
• CPC Class Codes: H04N 23/686 with a variable apex prism
• CPC Class Codes: H04N 5/145 Movement estimation for video coding H04N19/51

Abstract

A movement vector detection apparatus includes a detecting circuit for detecting a movement vector of an image in accordance with the amount of change in an image density value over a determined time at an arbitrary position of an image and a space gradient of an image signal at the arbitrary position, and a setting circuit for suitably setting a dimension and a shape of a unit operation area to output the movement vector in response to a space frequency of the input image.

Claims

1. A movement vector detection apparatus comprising:

means for forming a plurality of movement vector detection blocks in an input image by determining a dimension and/or a shape of each of the vector detection blocks in the input image;

controlling means for adaptively changing a dimension and/or shape of each of the blocks formed by said forming means in accordance with a spatial frequency of the input image; and

detection means for detecting a movement vector on the basis of a relation between the amount of change in an image density value in a predetermined time and a space gradient of an image signal of each of the plurality of blocks.

2. A movement vector detection apparatus according to claim 1, where said for forming means is arranged to determine a boundary of the areas by using the spatial gradient of the input image.

3. A movement vector detection apparatus according to claim 1, where said means for forming is arranged to determine a boundary of the areas by using a density different between chronologically sequential images.

4. An apparatus for detecting a movement vector for an image signal of an input image, comprising:

means for defining a plurality of movement vector detection blocks in an input image, each of said plurality of blocks having a dimension and/or a shape;

controlling means for adaptively changing a dimension and/or a shape of each of said plurality of areas on the basis of a spatial frequency of the input image; and

movement vector detecting means for detecting the movement vector in each of said plurality of blocks by effecting a correlation function operation or a matching operation between time-serial sequential images in said blocks.

5. A movement vector detection apparatus according to claim 4, where said means for dividing is arranged to determine a boundary of said plurality of areas based on a spatial gradient of image.

6. A movement vector detection apparatus according to claim 4, where said means for dividing is arranged to determine a boundary of said plurality of areas based on a time gradient represented by a density difference between chronologically sequential images.

7. An image pickup apparatus comprising:

image pickup means for photoelectrically converting an image focused on an image pickup plane, into an image pickup signal;

movement vector detection area setting means for setting a plurality of movement vector detection areas on said image pickup plane, wherein a dimension of each of said plurality of movement vector detection areas can be variably set;

control means for controlling said area setting means according to a spatial frequency of said image pickup signal output from said image pickup means so as to change and set the dimension of each of said plurality of movement vector detection areas according to said spatial frequency;

movement vector processing means for providing a movement vector by extracting an image signal in each of said plurality of movement vector detection areas; and

output means for outputting movement information representative of relative movement between said apparatus and said image, according to said movement vector provided by said movement vector processing means.

8. An apparatus according to claim 7, wherein said control means sets the dimension of the movement vector detection area to be smaller when the spatial frequency of the image signal of that area is high, and sets the dimension of the movement vector detection area to be larger when the spatial frequency of the image signal of that area is low.

9. An apparatus according to claim 8, wherein said control means determines boundaries of said plurality of movement vector detection areas on the basis of a spatial gradient in said image pickup signal.

10. An apparatus according to claim 9, wherein said control means determines a point where the value of the spatial gradient in said image pickup signal is substantially zero, as boundaries of said plurality of movement vector detection areas.

11. An apparatus according to claim 8, wherein said control means determines a boundary of said plurality of movement vector detection areas based on a time gradient of said image pickup signal.

12. An apparatus according to claim 11, wherein said control means determines a point where the value of the time gradient in said image pickup signal is substantially zero, as boundaries of said plurality of movement vector detection areas.

13. An apparatus according to claim 12, further comprising movement correction means for offsetting a relative movement between said apparatus and said image based on said movement vector.

14. An apparatus according to claim 13, wherein said movement correction means comprises optical correction means.

15. An apparatus according to claim 14, wherein said movement correction means comprises a variable vertical angle prism.

16. An apparatus according to claim 13, wherein said movement correction means comprises electronic correction means for electronically correcting said relative movement.

17. An apparatus according to claim 16, wherein said movement correction means comprises (i) an image memory for storing an image of one picture, and (ii) a memory control circuit for shifting a read-out range of said image memory on the basis of said movement vector.

18. An apparatus according to claim 17, wherein said read-out range is set to be smaller than one picture area, and wherein said apparatus further comprises expansion means for expanding image information which is read out of said image memory into one picture.

19. An apparatus according to claim 7, wherein said movement vector processing means provides the movement vector based on (i) a time gradient which is representative of a change of images in pictures of a plurality of fields, and (ii) a spatial gradient representative of a difference of density in the image of one picture.

20. An apparatus according to claim 19, further comprising movement correction means for offsetting a relative movement between said apparatus and said image based on said movement vector.

21. An apparatus according to claim 20, wherein said movement correction means comprises optical correction means.

22. An apparatus according to claim 21, wherein said movement correction means comprises a variable vertical angle prism.

23. An apparatus according to claim 20, wherein said movement correction means comprises electronic correction means for electronically offsetting said relative movement.

24. An apparatus according to claim 23, wherein said movement correction means comprises (i) an image memory for storing an image of one picture, and (ii) a memory control circuit for shifting a read-out range of said image memory on the basis of said movement vector.

25. An apparatus according to claim 24, wherein said read-out range is set to be smaller than one picture area, and wherein said apparatus further comprises expansion means for expanding image information which is read out, into one picture.

26. An image processing apparatus for processing image signals output from an image pickup device, comprising:

area setting means for setting a plurality of movement vector detection areas on a picture, wherein a dimension and/or a shape of each of said plurality of movement vector detection areas can be variably set;

control means for controlling said area setting means on the basis of a spatial frequency of image signals in each of said plurality of movement vector detection areas so as to change and set the dimension of each of said plurality of detection areas on the basis of said spatial frequency;

movement vector processing means for providing a movement vector by processing the image signal in each of said plurality of movement vector detection areas; and

movement correction means for correcting a movement of the picture on the basis of the movement vector provided by said movement vector operation means.

27. An apparatus according to claim 26, wherein said control means sets the dimension of the movement vector detection area to be smaller when the spatial frequency of the image signal of that area is high, and sets the dimension of the movement vector detection area to be larger when the spatial frequency of the image signal of that area is low.

28. An apparatus according to claim 27, wherein said control means determines boundaries of said plurality of movement vector detection areas on the basis of a spatial gradient of said image signals.

29. An apparatus according to claim 28, wherein said control means determines a point where the value of spatial gradient in said image signal is substantially zero, as a boundary of said plurality of movement vector detection area.

30. An apparatus according to claim 29, wherein said spatial gradient represents a difference between densities of adjacent pixels in one picture.

31. An apparatus according to claim 27, wherein said control means determines boundaries of said plurality of detection areas on the basis of a time gradient of said image signals.

32. An apparatus according to claim 31, wherein said control means determines a point where the time gradient in said image signal is substantially zero, as a boundary of the movement vector detection areas.

33. An apparatus according to claim 32, wherein said time gradient represents a difference between densities of images of a plurality of pictures.

34. An apparatus according to claim 26, wherein said movement vector processing means generates the movement vector utilizing a representation point matching method.

35. An apparatus according to claim 26, wherein said movement correction means comprises a variable vertical angle prism.

36. An apparatus according to claim 26, wherein said movement correction means comprises (i) an image memory for storing an image of one picture, (ii) a memory control circuit for shifting a read-out range of said image memory, which range is smaller than one picture, on the basis of said movement vector, and (iii) expansion means for expanding an image in the read-out range into one picture.