Face imaging system and method for controlling the face imaging system

• US 8,767,062 B2
• Filed: 01/24/2012
• Issued: 07/01/2014
• Est. Priority Date: 01/25/2011
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Omi, Takuhiro, Watanabe, Taito
• Primary Examiner(s): Kelley, Christopher S
• Assistant Examiner(s): Retallick, Kaitlin A
• Application Number:
  US13/356,988
• Publication Number:
  US 20120188355A1
• Time in Patent Office: 889 Days
• Field of Search: None
• US Class Current: 348/77
• CPC Class Codes: A61B 2503/22 Motor vehicles operators, e.g. drivers, pilots, captains
• CPC Class Codes: A61B 2562/0257 Proximity sensors
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/1114 Tracking parts of the body
• CPC Class Codes: A61B 5/1128 using image analysis A61B5/1127 takes precedence
• CPC Class Codes: A61B 5/163 by tracking eye movement, gaze, or pupil change
• CPC Class Codes: A61B 5/18 for vehicle drivers or machine operators
• CPC Class Codes: A61B 5/6893 Cars
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 20/59 inside of a vehicle, e.g. relating to seat occupancy, driver state or inner lighting conditions
• CPC Class Codes: G06V 20/597 Recognising the driver's state or behaviour, e.g. attention or drowsiness
• CPC Class Codes: G06V 40/16 Human faces, e.g. facial parts, sketches or expressions

Abstract

A projection unit projects light to a predetermined projection region in which a user'"'"'s face is supposed to be located. An imaging unit images a region including the projection region projected with light from the projection unit. A proximity detection unit detects that the user'"'"'s face approaches the projection unit. A first projection control unit causes the projection unit to stop or dim projection of light when the proximity detection unit detects the approach of the user'"'"'s face.

Claims

1. A face imaging system comprising:

a projection unit configured to project light to a predetermined projection region in which a user'"'"'s face is supposed to be located;

an imaging unit configured to image a region including the projection region projected with the light from the projection unit;

a proximity detection unit configured to detect approach of the user'"'"'s face, according to an image captured with the imaging unit, relative to the projection unit; and

a first projection control unit configured to cause the projection unit to stop or dim projection of the light when the proximity detection unit detects the approach of the user'"'"'s face, wherein

the imaging unit has a lens structure configured to cause blur in a region corresponding to an object in the image when the object approaches the projection unit,

the proximity detection unit includes;

an edge extraction unit configured to extract edge information from the image, the edge information reflecting a feature of an edge in the image, and

an edge determination unit configured to determine whether the edge information extracted with the edge extraction unit has blur,

the imaging unit is further configured to image the projection region to include a surrounding structure being constant in position relative to the imaging unit,

the edge determination unit is further configured to make a comparison between the edge information on a background region corresponding to the surrounding structure in the image and the edge information on an unfixed region other than the background region, thereby to determine whether the edge information on the unfixed region has blur; and

the face imaging system further comprises;

a blooming region detection unit configured to detect that;

a blooming region occurs entirely in pixels around a center of the image;

or

pixel values of the pixels entirely around the center of the image become greater than or equal to a blooming threshold, which is a predetermined large value representing the blooming region, wherein

the proximity detection unit is further configured to determine that the user'"'"'s face approaches the projection unit when the blooming region detection unit detects the blooming region or detects that the pixel values become greater than or equal to the blooming threshold.

4. The face imaging system according to claim 1, further comprising:

a face recognition unit configured to detect a face region corresponding to the user'"'"'s face in the image, wherein

the proximity detection unit is further configured to detect the approach of the user'"'"'s face according to a size of the face region when the face recognition unit detects the face region.

5. The face imaging system according to claim 1, wherein

the proximity detection unit includes a distance detection unit configured to detect a distance of the object in the projection region, and

the proximity detection unit is further configured to detect approach of the object relative to the projection unit according to the distance detected with the distance detection unit.

6. The face imaging system according to claim 1, wherein

the approach of the user'"'"'s face is approach of an eye of the user.

2. A face imaging system comprising:

a projection unit configured to project light to a predetermined projection region in which a user'"'"'s face is supposed to be located;

an imaging unit configured to image a region including the projection region projected with the light from the projection unit;

a proximity detection unit configured to detect approach of the user'"'"'s face, according to an image captured with the imaging unit, relative to the projection unit;

a first projection control unit configured to cause the projection unit to stop or dim projection of the light when the proximity detection unit detects the approach of the user'"'"'s face;

an imaging control unit configured to control an exposure condition of the imaging unit;

a second projection control unit configured to control a projection timing of the light from the projection unit according to an exposure timing of the imaging unit; and

a concealment detection unit configured to detect concealment of the imaging unit with an obstacle according to the image, wherein

when the concealment detection unit detects the concealment of the imaging unit;

the imaging control unit increases an exposure interval of the imaging unit; and

/or

the first projection control unit causes the projection unit to stop projection of the light or to dim the projection of the light; and

the face imaging system further comprises;

a blooming region detection unit configured to detect that;

a blooming region occurs entirely in pixels around a center of the image;

or

pixel values of the pixels entirely around the center of the image become greater than or equal to a blooming threshold, which is a predetermined large value representing the blooming region, wherein

the proximity detection unit is further configured to determine that the user'"'"'s face approaches the projection unit when the blooming region detection unit detects the blooming region or detects that the pixel values become greater than or equal to the blooming threshold.

7. The face imaging system according to claim 2, further comprising:

a face recognition unit configured to detect a face region corresponding to the user'"'"'s face in the image, wherein

the proximity detection unit is further configured to detect the approach of the user'"'"'s face according to a size of the face region when the face recognition unit detects the face region.

8. The face imaging system according to claim 2, wherein

the proximity detection unit includes a distance detection unit configured to detect a distance of an object in the projection region, and

the proximity detection unit is further configured to detect approach of the object relative to the projection unit according to the distance detected with the distance detection unit.

3. A face imaging system comprising:

a projection unit configured to project light to a predetermined projection region in which a user'"'"'s face is supposed to be located;

an imaging unit configured to image a region including the projection region projected with the light from the projection unit;

a proximity detection unit configured to detect approach of the user'"'"'s face, according to an image captured with the imaging unit, relative to the projection unit;

a first projection control unit configured to cause the projection unit to stop or dim projection of the light when the proximity detection unit detects the approach of the user'"'"'s face; and

a black crushing detection unit configured to detect that;

black crushing occurs entirely in pixels around a center of the image;

or

pixel values of the pixels entirely around the center of the image become less than or equal to a black crushing threshold, which is a predetermined small value representing the black crushing, wherein

the proximity detection unit is further configured to determine that the user'"'"'s face approaches the projection unit when the black crushing detection unit detects the black crushing or detects that the pixel values become less than or equal to the black crushing threshold.

9. The face imaging system according to claim 3, further comprising:

a face recognition unit configured to detect a face region corresponding to the user'"'"'s face in the image, wherein

the proximity detection unit is further configured to detect the approach of the user'"'"'s face according to a size of the face region when the face recognition unit detects the face region.

10. The face imaging system according to claim 3, wherein

the proximity detection unit includes a distance detection unit configured to detect a distance of an object in the projection region, and

the proximity detection unit is further configured to detect approach of the object relative to the projection unit according to the distance detected with the distance detection unit.

11. The face imaging system according to claim 3, further comprising:

a blooming region detection unit configured to detect that;

blooming region occurs entirely in pixels around a center of the image;

or

pixel values of the pixels entirely around the center of the image become greater than or equal to a blooming threshold, which is a predetermined large value representing the blooming region, wherein

the proximity detection unit is further configured to determine that the user'"'"'s face approaches the projection unit when the blooming region detection unit detects the blooming region or detects that the pixel values become greater than or equal to the blooming threshold.