Perfecting the Effect of Flash within an Image Acquisition Devices using Face Detection

• US 20090102949A1
• Filed: 07/05/2007
• Published: 04/23/2009
• Est. Priority Date: 06/26/2003
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: FotoNation Vision Limited (Adeia Inc.)
• Inventors: Steinberg, Eran, Bigioi, Petronel, Corcoran, Peter
• Granted Patent: US 7,693,311 B2
• Time in Patent Office: Days
• US Class Current: 348/234
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

Within a digital acquisition device with a built in flash unit, the exposure of an acquired digital image is perfected using face detection in the acquired image is provided. Groups of pixels that correspond to plural images of faces are identified within a digitally acquired image, and corresponding image attributes to the group of pixels are determined. An analysis is performed of the corresponding attributes of the groups of pixels. It is then determined to activate the built-in flash unit based on the analysis. An intensity of the built-in flash unit is determined based on the analysis. Alternatively based on similar analysis, a digital simulation of the fill flash is performed on the image.

Claims

1. :

Within a digital camera, method of digital image processing using face detection to achieve a desired luminance contrast, comprising the steps of;

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

(b) determining first initial values of luminance of pixels of the group of pixels;

(c) determining second initial values of luminance of pixels other than pixels of the group of pixels;

(d) comparing the first and second initial values to determine an initial luminance contrast; and

(e) determining properties of a fill flash for providing adjusted values of luminance for at least some of the pixels of the digital image based on a comparison of the initial luminance contrast and the desired luminance contrast.

2. Within a digital camera, one or more processor readable storage devices having processor readable code embodied thereon, said processor readable code for programming one or more processors to perform a method of digital image processing using face detection to achieve a desired luminance contrast, comprising the steps of:

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

(b) determining first initial values of luminance of pixels of the group of pixels;

(c) determining second initial values of luminance of pixels other than pixels of the group of pixels;

(d) comparing the first and second initial values to determine an initial luminance contrast; and

(e) determining properties of a fill flash for providing adjusted values of luminance for at least some of the pixels of the digital image based on a comparison of the initial luminance contrast and the desired luminance contrast.