Imaging apparatus for detecting a face image and imaging method

• US 8,300,136 B2
• Filed: 06/24/2009
• Issued: 10/30/2012
• Est. Priority Date: 06/26/2008
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamasaki, Ryo
• Primary Examiner(s): CUTLER, ALBERT H
• Application Number:
  US12/490,315
• Publication Number:
  US 20090322935A1
• Time in Patent Office: 1,224 Days
• Field of Search: None
• US Class Current: 348/346
• CPC Class Codes: G02B 7/36 using image sharpness techniques , e.g. image processing techniques for generating autofocus signals image data processing per se G06T; in cameras having a solid state image sensor H04N23/67
• CPC Class Codes: G03B 13/36 Autofocus systems
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body

Abstract

An imaging apparatus includes an imaging unit configured to receive an optical image transmitted through a lens unit and configured to convert the image into image data, a target image detection unit configured to detect a target image satisfying a predetermined form from the image data converted by the imaging unit, and a focus control unit configured to move a focus position of the lens unit by a predetermined amount according to a result of the target image detected by the target image detection unit. The target image detection unit detects the target image from image data converted by the imaging unit in the moved focus position when the focus control unit moves the focus position of the lens unit by the predetermined amount according to the detected result of the target image.

Claims

1. An imaging apparatus comprising:

an imaging unit configured to receive an optical image transmitted through a lens unit and configured to convert the image into image data;

a face image detection unit configured to detect a face image from the image data converted by the imaging unit;

a size determination unit configured to determine whether the face image detected by the face image detection unit is larger than a predetermined size; and

a focus control unit configured to move a focus position of the lens unit by a predetermined amount,

wherein, in a case where the face image detection unit does not succeed in detecting the face image, the focus control unit moves the focus position of the lens unit by the predetermined amount and the face image detection unit detects the face image from image data converted by the imaging unit in the moved focus position,

wherein, in a case where the face image detection unit does succeed in detecting the face image but the size determination unit determines that the face image detected by the face image detection unit is not larger than the predetermined size, the focus control unit moves the focus position of the lens unit by the predetermined amount and the face image detection unit detects the face image from image data converted by the imaging unit in the moved focus position, and

wherein the focus control unit does not move the focus position of the lens unit by the predetermined amount and the face image detection unit ends detection of the face image, when the face image detection unit succeeds in detecting the face image and the size determination unit determines that the face image detected by the face image detection unit is larger than the predetermined size.

2. The imaging apparatus according to claim 1, wherein

the predetermined amount is decided based on a depth of field of the lens unit.

3. An imaging apparatus comprising:

an imaging unit configured to receive an optical image transmitted through a lens unit and to convert the image into image data;

a face image detection unit configured to detect a face image from the image data converted by the imaging unit;

a display unit configured to display a result of the face image detected by the face image detection unit;

a determination unit configured to determine whether a user has provided an instruction for moving the lens position;

a focus lens position calculation unit configure to determine a depth of field of the lens unit and calculate a plurality of focus positions of the lens unit corresponding to divided up steps in the determined depth of field; and

a focus control unit configured to move a focus position of the lens unit by a predetermined amount to a next focus position step when the determination unit determines that the user has provided the instruction for moving the lens position,

wherein in a case where the result of the face image detected by the face image detection unit is displayed on the display unit and the determination unit determines that a user has not provided the instruction for moving the lens position with a predetermined time after the display unit displays the result, the focus control unit does not move the focus position of the lens unit,

wherein in a case where the result of the face image detected by the face image detection unit is displayed on the display unit and the determination unit determines that the user has provided the instruction for moving the lens position with the predetermined time after the display unit displays the result, the focus control unit moves the focus position of the lens unit by the predetermined amount to the next focus lens position step, and

wherein the face image detection unit detects the face image from image data converted by the imaging unit in the moved focus position when the focus control unit moves the focus position of the lens unit by the predetermined amount.

4. The imaging apparatus according to claim 3, wherein

the focus control unit decides whether the focus position of the lens unit is moved to a closest distance side or an infinite distance side.

5. The imaging apparatus according to claim 3, wherein

the focus control unit automatically moves the focus position of the lens unit by a predetermined amount, and the face image detection unit detects the face image again from image data converted by the imaging unit in the moved focus position, when the face image detection unit cannot detect the face image, and

the focus control unit moves the focus position of the lens unit by a predetermined amount, and the face image detection unit detects the face image again from image data converted by the imaging unit in the moved focus position, when the face image detection unit detects the face image and the determination unit determines that the user has provided the instruction for moving the lens position.

6. An imaging method comprising:

detecting a face image from image data converted by an imaging unit configured to receive an optical image transmitted through a lens unit and to convert the image into the image data;

determining whether the face image detected from the image data is larger than a predetermined size; and

moving a focus position of the lens unit by a predetermined amount,

wherein, in a case where detection of the face image does not succeed, the focus position of the lens unit is moved by the predetermined amount and the face image is detected from the image data converted by the imaging unit in the moved focus position,

wherein, in a case where detection of the face image does succeed but it is determined that the detected face image is not larger than the predetermined size, the focus position of the lens unit is moved by the predetermined amount and the face image is detected from the image data converted by the imaging unit in the moved focus position, and

wherein the focus position of the lens unit is not moved by the predetermined amount and detection of the face image is ended, when the face image is detected and the detected face image is larger than the predetermined size.

7. An imaging method comprising:

detecting a face image from image data converted by an imaging unit configured to receive an optical image transmitted through a lens unit and to convert the image into the image data;

displaying a result of the detected face image;

determining whether a user has provided an instruction for moving the lens position;

determining a depth of field of the lens unit and calculating a plurality of focus positions of the lens unit corresponding to divided up steps in the determined depth of field; and

moving a focus position of the lens unit by a predetermined amount to a next focus position step when it is determined that the user has provided the instruction for moving the lens position;

wherein in a case where the result of the detected face image is displayed and it is determined that the user has not provided the instruction for moving the lens position within a predetermined time after the result is displayed, the focus position of the lens unit is not moved,

wherein in a case where the result of the detected face image is displayed and it is determined that the user has provided the instruction for moving the lens position with the predetermined time after the result is displayed, the focus position of the lens unit is moved by the predetermined amount to the next focus lens position step, and

wherein the face image is detected from the image data converted by the imaging unit in the moved focus position when the focus position of the lens unit is moved by the predetermined amount.