Face Detection in Mid-Shot Digital Images

• US 20090196466A1
• Filed: 02/05/2008
• Published: 08/06/2009
• Est. Priority Date: 02/05/2008
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: FotoNation Vision Limited (Adeia Inc.)
• Inventors: Poenaru, Vlad, Steinberg, Eran, Capata, Adrian
• Granted Patent: US 8,494,286 B2
• Time in Patent Office: Days
• US Class Current: 382/118
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06V 40/161 Detection; Localisation; Normalisation
• CPC Class Codes: H04N 2101/00 Still video cameras
• 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 23/80 Camera processing pipelines; Components thereof
• CPC Class Codes: H04N 5/275 Generation of keying signals

Abstract

A method for detecting a face in a mid-shot digital image of a person comprises capturing first and second mid-shot digital images of nominally the same scene using different capture settings such that the foreground is differently differentiated from the background in each image, and comparing the first and second images to determine the foreground region of the images. A portion of the foreground region likely to correspond to a face is estimated based upon the geometry of the foreground region.

Claims

1. A method for detecting a face in a mid-shot digital image of a person, the method comprising:

(a) capturing first and second mid-shot digital images of nominally the same scene using different capture settings such that the foreground is differently differentiated from the background in each image,

(b) comparing the first and second images to determine the foreground region of the images, and

(c) identifying a portion of the foreground region likely to correspond to a face based upon the geometry of the foreground region.

2. The method of claim 1, wherein the different capture settings comprise taking one image using a flash and taking the other image without using a flash.

3. The method of claim 1, wherein the different capture settings comprise taking one image with the foreground more in focus than the background and taking the other image with the background more in focus than the foreground.

4. The method of claim 1, wherein the first and second images have different pixel resolutions.

5. The method of claim 4, further comprising matching the pixel resolutions of the first and second images prior to step (b).

6. The method of claim 1, wherein the first and second images are captured by a digital camera.

7. The method of claim 6, wherein the first image is a relatively high resolution main image, and wherein the second image is a relatively low resolution pre- or post-view version of the first image.

8. The method of claim 6, wherein the first and second images are relatively low resolution pre- and/or post-view versions of a higher resolution main image of said scene also captured by the camera.

9. A digital image acquisition and processing apparatus comprising means for capturing first and second mid-shot digital images of nominally the same scene using different capture settings such that the foreground is differently differentiated from the background in each image, means for comparing the first and second images to determine the foreground region of the images, and means for identifying a portion of the foreground region likely to correspond to a face based upon the geometry of the foreground region.