Face detection device, imaging apparatus and face detection method

• US 9,495,578 B2
• Filed: 01/05/2012
• Issued: 11/15/2016
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Okada, Miyuki, Nakajima, Ken
• Primary Examiner(s): Park, Chan
• Assistant Examiner(s): RICE, ELISA M
• Application Number:
  US13/344,191
• Publication Number:
  US 20120114179A1
• Time in Patent Office: 1,776 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06V 40/161 Detection; Localisation; Normalisation
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body

Abstract

A face detection device for detecting the face of a person in an input image may include the following elements: a face detection circuit including a hardware circuit configured to detect a face in an input image; a signal processing circuit configured to perform signal processing based on an input image signal in accordance with a rewritable program including a face detection program for detecting a face in an input image; and a controller configured to allow the face detection circuit and the signal processing circuit to perform face detection on an image of a frame or on respective images of adjacent frames among consecutive frames, and to control face detection by the signal processing circuit on the basis of a face detection result obtained by the face detection circuit.

Claims

1. An image processing apparatus, comprising:

a controller configured to set a detection parameter;

a face detection circuit including a dedicated hardware configured to detect first face information in an input image based on the detection parameter, wherein the first face information indicates a face detection range; and

a programmable signal processing circuit configured to detect second face information based on the first face information, wherein the controller is configured to update the detection parameter based on the second face information in accordance with a rewritable program including a face detection program for detecting the second face information in the input image.

2. The image processing apparatus according to claim 1, wherein the input image is captured by an imaging unit of the image processing apparatus.

3. The image processing apparatus according to claim 1, wherein the first face information is a detection result of the face detection circuit and the second face information is a detection result of the programmable signal processing circuit.

4. The image processing apparatus according to claim 1, wherein the first face information includes at least one of:

coordinates of a face area of a face detected in the input image by the face detection circuit, size of the face area and a face search angle indicative of a tilt of the image processing apparatus.

5. The image processing apparatus according to claim 1, wherein the second face information includes at least one of:

a direction of a detected face in the input image, a tilt of the detected face, an evaluation value of the detected face and detection error information.

6. The image processing apparatus according to claim 5, wherein the evaluation value of the detected face is a correlation value obtained by face template matching.

7. The image processing apparatus according to claim 5, wherein the detection error information indicates that a face does not exist in the face area detected by the face detection circuit.

8. The image processing apparatus according to claim 4, wherein the tilt of the imaging apparatus is detected by a sensor.

9. The image processing apparatus according to claim 4, wherein the face search angle is set according to at least one of:

a user input, and

frequency information of the face search angle set previously.

10. An image processing method, comprising:

in an image processing apparatus;

setting a detection parameter;

detecting, by a face detection circuit including a dedicated hardware, first face information in an input image based on the detection parameter, wherein the first face information indicates a face detection range; and

detecting, by a programmable signal processing circuit, second face information based on the detected first face information, wherein the detection parameter is updated based on the second face information in accordance with a rewritable program including a face detection program for detecting the second face information in the input image.

11. The image processing method according to claim 10, wherein the input image is captured by an imaging unit of the image processing apparatus.

12. The image processing method according to claim 10, wherein the first face information is a detection result of the face detection circuit of the image processing apparatus and the second face information is a detection result of the programmable signal processing circuit of the image processing apparatus.

13. The image processing method according to claim 10, wherein the first face information includes at least one of:

coordinates of a face area of a face detected in the input image, size of the face area and a face search angle indicative of a tilt of the image processing apparatus.

14. The image processing method according to claim 10, wherein the second face information includes at least one of:

a direction of a detected face in the input image, a tilt of the detected face, an evaluation value of the detected face and detection error information.

15. The image processing method according to claim 14, wherein the evaluation value of the detected face is a correlation value obtained by face template matching.

16. The image processing method according to claim 14, wherein the detection error information indicates that a face does not exist in the face area detected by the face detection circuit.

17. The image processing method according to claim 13, wherein the tilt of the imaging apparatus is detected by a sensor.

18. The image processing method according to claim 13, wherein the face search angle is set according to at least one of:

a user input, and

frequency information of the face search angle set previously.

19. A non-transitory computer readable medium having stored thereon, a set of computer-executable instructions for causing a computer to perform steps comprising:

setting a detection parameter;

detecting, by a face detection circuit including a dedicated hardware, first face information in an input image based on the detection parameter, wherein the first face information indicates a face detection range; and

detecting, by a programmable signal processing circuit, second face information based on the detected first face information, wherein the detection parameter is updated based on the second face information in accordance with a rewritable program including a face detection program for detecting the second face information in the input image.

20. An image processing apparatus, comprising:

a face detection circuit including a dedicated hardware circuit configured to detect a face in an input image based on a detection parameter;

a programmable signal processing circuit configured to perform signal processing based on an input image signal in accordance with a program including a face detection program; and

a controller configured to control face detection by the programmable signal processing circuit based on a face detection result obtained by the face detection circuit,

wherein the controller is configured to update the detection parameter based on the input image signal in accordance with a rewritable program including the face detection program for detecting the second face information in the input image,

wherein a face detection speed of the face detection circuit is greater than a face detection speed of the signal processing circuit,

wherein the controller sets a face detection area including a face area detected by the face detection circuit, and

wherein the signal processing circuit performs face detection only in the face detection area of the input image set by the controller.

21. An image processing apparatus, comprising:

a controller configured to set a detection parameter;

a face detection circuit including a dedicated hardware configured to detect first face information in an input image based on the detection parameter, wherein the first face information indicates a face detection range; and

a programmable signal processing circuit configured to detect second face information based on the detected first face information,

wherein the controller is configured to update the detection parameter based on the second face information in accordance with a rewritable program including a face detection program for detecting the second face information in the input image, and

wherein a face detection speed of the face detection circuit is greater than a face detection speed of the signal processing circuit.