Digital image processing using face detection and skin tone information

• US 8,908,932 B2
• Filed: 01/23/2013
• Issued: 12/09/2014
• Est. Priority Date: 06/26/2003
• Status: Expired due to Term

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: DigitalOptics Corporation Europe Limited (Adeia Inc.)
• Inventors: Corcoran, Peter, Barcovschi, Igor, Steinberg, Eran, Prilutsky, Yury, Bigioi, Petronel
• Primary Examiner(s): Seth, Manav
• Application Number:
  US13/748,462
• Publication Number:
  US 20130236052A1
• Time in Patent Office: 685 Days
• Field of Search: 348/61, 348/68, 348 77- 78, 348/143, 348/152, 348/155, 348/158, 348/169, 348/207.99, 3482201-2291
• US Class Current: 382/118
• CPC Class Codes: A61B 5/1176 Recognition of faces
• CPC Class Codes: G06F 16/784 the detected or recognised objects being people
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G06V 40/16 Human faces, e.g. facial parts, sketches or expressions
• CPC Class Codes: G06V 40/161 Detection; Localisation; Normalisation
• CPC Class Codes: G06V 40/168 Feature extraction; Face representation
• CPC Class Codes: G06V 40/169 Holistic features and representations, i.e. based on the facial image taken as a whole
• 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 23/675 comprising setting of focusing regions
• CPC Class Codes: H04N 23/695 Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof

Abstract

A technique for processing a digital image uses face detection to achieve one or more desired image processing parameters. A group of pixels is identified that corresponds to a face image within the digital image. A skin tone is detected for the face image by determining one or more default color or tonal values, or combinations thereof, for the group of pixels. Values of one or more parameters are adjusted for the group of pixels that correspond to the face image based on the detected skin tone.

Claims

1. A method of identifying a face image within a digital image by detecting and tracking a face image within a stream of images using skin tone information, comprising:

identifying a group of pixels that correspond to a face image within the digital image;

generating in-camera, capturing or otherwise obtaining in-camera a stream of images including said face image;

tracking said face image within said stream of images;

detecting a skin tone for the face image by determining one or more color or tonal values, or combinations thereof, for the group of pixels and comparing with one or more default color or tonal values, or combinations thereof; and

adjusting values of one or more parameters for the group of pixels, including adjusting a luminance of each face image separately depending on the skin tone of each face image.

2. The method of claim 1, wherein the adjusting values of luminance comprises selectively applying fill-flash to regions within the face image in an amount based on the detected skin tone to open up shadows within the face image.

3. The method of claim 1, further comprising repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting values of one or more parameters comprises applying fill-flash to the two face images in different relative amounts depending on the different skin tones.

4. The method of claim 1, further comprising repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises adjusting luminance values of pixels of the two face images in different relative amounts depending on the different skin tones.

5. The method of claim 1, wherein the color or tonal values for the group of pixels comprise one or more average color or tonal values.

6. The method of claim 5, wherein the color or tonal values comprise multiple colors or tones, or combinations thereof, determined for each of multiple regions of the face image.

7. An image acquisition apparatus including an imaging optical system and digital image detector and storage medium, and having stored therein program instructions for programming one or more processors to perform a method of processing a digital image using face detection to achieve one or more desired image processing parameters, the method comprising:

identifying a group of pixels that correspond to a face image within the digital image;

generating in-camera, capturing or otherwise obtaining in-camera a stream of images including said face image;

tracking said face image within said stream of images;

detecting a skin tone for the face image by determining one or more color or tonal values, or combinations thereof, for the group of pixels and comparing with one or more default color or tonal values, or combinations thereof; and

adjusting values of one or more parameters for the group of pixels, including adjusting a luminance of each face image separately depending on the skin tone of each face image.

8. The apparatus of claim 7, wherein the adjusting values of luminance comprises selectively applying fill-flash to regions within the face image in an amount based on the detected skin tone to open up shadows within the face image.

9. The apparatus of claim 7, wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises applying fill-flash to the two face images in different relative amounts depending on the different skin tones.

10. The apparatus of claim 9, wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises adjusting luminance values of pixels of the two face images in different relative amounts depending on the different skin tones.

11. The apparatus of claim 7, wherein the color or tonal values for the group of pixels comprise one or more average color or tonal values.

12. The apparatus of claim 11, wherein the color or tonal values comprise multiple colors or tones, or combinations thereof, determined for each of multiple regions of the face image.

13. One or more non-transitory digital storage devices having embodied therein program instructions for programming one or more processors to perform a method of processing a digital image using face detection to achieve one or more desired image processing parameters, the method comprising:

identifying a group of pixels that correspond to a face image within the digital image;

generating in-camera, capturing or otherwise obtaining in-camera a stream of images including said face image;

tracking said face image within said stream of images;

detecting a skin tone for the face image by determining one or more color or tonal values, or combinations thereof, for the group of pixels and comparing with one or more default color or tonal values, or combinations thereof; and

adjusting values of one or more parameters for the group of pixels, including adjusting a luminance of each face image separately depending on the skin tone of each face image.

14. The one or more storage devices of claim 13, wherein the adjusting values of luminance comprises selectively applying fill-flash to regions within the face image in an amount based on the detected skin tone to open up shadows within the face image.

15. The one or more storage devices of claim 13, wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises applying fill-flash to the two face images in different relative amounts depending on the different skin tones.

16. The one or more storage devices of claim 13, wherein the method further comprises repeating the identifying, detecting and adjusting for a second face image having a different skin tone than the first face image, and the adjusting comprises adjusting luminance values of pixels of the two face images in different relative amounts depending on the different skin tones.

17. The one or more storage devices of claim 13, wherein the color or tonal values for the group of pixels comprise one or more average color or tonal values.

18. The one or more storage devices of claim 17, wherein the color or tonal values comprise multiple colors or tones, or combinations thereof, determined for each of multiple regions of the face image.