CAMERA HAVING A FOCUS ADJUSTING SYSTEM AND A FACE RECOGNITION FUNCTION

• US 20080136958A1
• Filed: 12/10/2007
• Published: 06/12/2008
• Est. Priority Date: 12/11/2006
• Status: Abandoned Application

• Current Assignee: Pentax Corporation (Hoya Corporation)
• Original Assignee: Pentax Corporation (Hoya Corporation)
• Inventors: NAKAHARA, Naoto
• Application Number:
  US11/953,311
• Publication Number:
  US 20080136958A1
• Time in Patent Office: Days
• US Class Current: 348/345
• CPC Class Codes: G06V 40/166 using acquisition arrangements
• CPC Class Codes: H04N 23/61 based on recognised objects
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body
• CPC Class Codes: H04N 23/635 Region indicators; Field of view indicators
• CPC Class Codes: H04N 23/673 based on contrast or high frequency components of image signals, e.g. hill climbing method
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements

Abstract

A camera includes an image pickup device; a focus adjusting device which captures an object image at different positions while the focusing lens group is moved to detect an in-focus lens position, based on image signals of the object images, and the focusing lens group is moved to this in-focus lens position; and a face recognition device for recognizing a face image based on the image signals. When the face recognition device recognizes the face image, the focus adjusting device performs the focus search process toward the near extremity if the area size of the face image is smaller than a predetermined threshold value, and the focusing lens group moves toward the far extremity if the area size of the face image is equal to or greater than the predetermined threshold value.

Claims

1. A camera having a focus adjusting system and a face recognition function, comprising:

an image pickup device for capturing an object image formed via a photographing optical system including a focusing lens group movable along an optical axis;

a focus adjusting device which performs a focus search process, wherein said image pickup device is activated to capture an object image at each of a plurality of different positions of said focusing lens group in said optical axis direction while said focusing lens group is moved along said optical axis to detect an in-focus lens position of said focusing lens group in said optical axis direction, based on image signals of said object images obtained at said plurality of different positions of said focusing lens group, and wherein said focusing lens group is moved to said in-focus lens position detected by said focus search process; and

a face recognition device for recognizing a face image based on said image signals,

wherein, when said face recognition device recognizes said face image, said focus adjusting device performs said focus search process so that said focusing lens group moves toward a near extremity in the case where the area size of said face image is smaller than a predetermined threshold value, and so that said focusing lens group moves toward a far extremity in the case where said area size of said face image is one of equal to and greater than said predetermined threshold value.

2. The camera having a focus adjusting system and a face recognition function according to claim 1, wherein, when said face recognition device recognizes said face image, said focus adjusting device detects said in-focus lens position of said focusing lens group as a position at which an in-focus state is achieved on said face image recognized by said face recognition device.

3. The camera having a focus adjusting system and a face recognition function according to claim 1, wherein, when said face recognition device recognizes said face image, said focus adjusting device sets an image area which includes said face image to serve as a focus detection area, and detects said in-focus lens position of said focusing lens group based on an image signal of said face image formed in said focus detection area.

4. The camera having a focus adjusting system and a face recognition function according to claim 3, wherein the size of said focus detection area remains unchanged regardless of the size of said image area.

5. The camera having a focus adjusting system and a face recognition function according to claim 3, wherein said focus adjusting device detects said in-focus lens position of said focusing lens group as a position thereof in said optical axis direction at which a peak contrast value in said image signal of said face image formed in said focus detection area is obtained.

6. The camera having a focus adjusting system and a face recognition function according to claim 5, wherein, upon said peak contrast value being obtained during said focus search process, said focus adjusting device terminates said focus search process and moves said focusing lens group to said position at which said peak contrast value is obtained.

7. The camera having a focus adjusting system and a face recognition function according to claim 1, wherein said photographing optical system comprises a zoom lens, and

wherein said predetermined threshold value is determined based on a currently-set focal length of said zoom lens.

8. The camera having a contrast-detection focus adjusting system according to claim 1, further comprising a monitor which displays said object image captured by said image pickup device,

wherein, when said face recognition device recognizes said face image while said focus adjusting device performs said focus search process, an image signal of an object image which is formed in an image area including said face image is extracted from among said image signals of said object images captured at said plurality of different positions of said focusing lens group to indicate a zoom-in image of said face image on said monitor.

9. The camera having a focus adjusting system a face recognition function according to claim 8, wherein said object image captured by said image pickup device is displayed on said monitor after said focusing lens group is moved to said in-focus lens position following termination of said focus search process.

10. The camera having a focus adjusting system a face recognition function according to claim 8, wherein, upon focus being achieved on said image area including said face image, an identification indication which visually identifies said image area including said face image is indicated on said monitor.

11. The camera having a focus adjusting system and a face recognition function according to claim 10, wherein said identification indication comprises a highlighted frame which surrounds said face image.

12. The camera having a contrast-detection focus adjusting system according to claim 1, further comprising a monitor which displays said object image captured by said image pickup device,

wherein, when said face recognition device recognizes said face image while said focus adjusting device performs said focus search process, the manner of indication of said monitor is switched to a zoom-in indication manner in which an image of the image signal obtained from an area of said recognized face image is zoomed in to be indicated on said monitor as a zoom-in image, while said focus adjusting device performs said focus search process.

13. The camera having a focus adjusting system a face recognition function according to claim 12, wherein the manner of indication of said monitor is switched back to the aforementioned normal manner upon completion of the focusing drive process, when said focus search process is terminated.

14. A camera having a focus adjusting system and a face recognition function, comprising:

an image pickup device for capturing an object image formed via a photographing optical system including a focusing lens group movable along an optical axis;

a focus adjusting device which performs a focus search process, wherein said image pickup device is activated to capture an object image at each of a plurality of different positions of said focusing lens group in said optical axis direction while said focusing lens group is moved along said optical axis between a near extremity thereof and a far extremity thereof to detect an in-focus lens position of said focusing lens group in said optical axis direction, based on image signals of said object images obtained at said plurality of different positions of said focusing lens group, and wherein said focusing lens group is moved to said in-focus lens position detected by said focus search process; and

a face recognition device for recognizing a face image based on said image signals,

wherein, when said face recognition device recognizes said face image, said focus adjusting device performs said focus search process so that said focusing lens group moves from said far extremity toward said near extremity in the case where the area size of said face image is smaller than a predetermined threshold value, and so that said focusing lens group moves from said near extremity toward said far extremity in the case where said area size of said face image is one of equal to and greater than said predetermined threshold value.

15. A camera having a focus adjusting system and face recognition function, comprising:

an image pickup device for capturing an object image formed via a photographing optical system including a focusing lens group which is movable along an optical axis;

a face recognition device for recognizing face images based on said image signals;

a focus adjusting device which performs a focus search process, wherein said image pickup device is activated to capture said object image at each of a plurality of different positions of said focusing lens group in said optical axis direction while said focusing lens group is moved along said optical axis to detect a focus state based on image signals of said object images obtained at said plurality of different positions of said focusing lens group; and

a controller which determines an average value of areas of said face images recognized by said face recognition device, and controls said focus adjusting device so as to perform said focus search process so that said focusing lens group moves from a near extremity thereof toward a far extremity thereof in the case where said average value is one of equal to and greater than a predetermined value and so that said focusing lens group moves from said far extremity toward said near extremity if said average value is smaller than said predetermined value, when said face recognition device recognizes said face images.

16. The camera having a focus adjusting system and face recognition function according to claim 15, wherein, when said face recognition device recognizes said face images, said controller controls said focus adjusting device so as to detect a focus state on each of said areas of said face images recognized by said face recognition device to determine in-focus lens positions of said focusing lens group at which an in-focus state is achieved on said face images recognized by said face recognition device, respectively, and controls said image pickup device to as to perform an image capturing operation at each of said in-focus lens positions by moving said focusing lens group sequentially to said in-focus lens positions.

17. The camera having a focus adjusting system and face recognition function according to claim 16, wherein said controller controls said image pickup device so as to perform said image capturing operation on said recognized face images in a sequential order, starting from an in-focus lens position among said in-focus lens positions which is the closest to a stop position of the focusing lens group at a termination of said focus search process, and controls said image pickup device so as to perform said image capturing operation at each of said in-focus lens positions by moving said focusing lens group sequentially to said in-focus lens positions.

18. The camera having a focus adjusting system and face recognition function according to claim 16, wherein said predetermined value is determined in accordance with a focal length of said photographing optical system to become greater as said focal length of said photographing optical system becomes longer.

19. The camera having a focus adjusting system and face recognition function according to claim 15, wherein, when said face recognition device recognizes no face image, said focus detecting device performs said focus search process based on an image signal of a face image formed in a predetermined focus detection area.

20. The camera having a focus adjusting system and face recognition function according to claim 15, further comprising a monitor which displays said object image captured by said image pickup device,

wherein said controller sets focus detection areas to correspond to said face images recognized by said face recognition device, respectively, and

wherein said monitor displays square brackets which visually indicate said focus detection areas, said square brackets being superimposed on said face images, respectively.

21. The camera having a focus adjusting system and face recognition function according to claim 20, wherein, when said image pickup device performs said image capturing operation at each of said in-focus lens positions while said focus detecting device moves said focusing lens group sequentially to said in-focus lens positions, said controller makes said monitor indicate in-focus frames which visually identify face images on which an in-focus state is achieved, respectively, every time said image pickup device performs said image capturing operation.

22. The camera having a contrast-detection focus adjusting system according to claim 15, further comprising a monitor which displays said object image captured by said image pickup device,

wherein, when said face recognition device recognizes said face image while said focus adjusting device performs said focus search process, the manner of indication of said monitor is switched to a zoom-in indication manner in which an image of the image signal obtained from an area of said recognized face image is zoomed in to be indicated on said monitor as a zoom-in image, while said focus adjusting device performs said focus search process.

23. The camera having a focus adjusting system a face recognition function according to claim 22, wherein the manner of indication of said monitor is switched back to the aforementioned normal manner upon completion of the focusing drive process, when said focus search process is terminated.