Mobile Electronic Device Having Camera With Improved Auto White Balance

• US 20110211089A1
• Filed: 02/26/2010
• Published: 09/01/2011
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Robinson, James Alexander, Purdy, Michael Lorne, Drader, Marc
• Granted Patent: US 9,369,685 B2
• Time in Patent Office: Days
• US Class Current: 348/223.1
• CPC Class Codes: H04N 1/00307 with a mobile telephone apparatus constructional features of portable telephone sets H04M1/0202; mobile radio systems H04W84/00
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

An improved mobile electronic device and camera provide an improved auto white balance system where constraints can be imposed the correlated color temperature (CCT) that is employed by the auto white balance system. For instance, if a distance between a subject and the camera is determined to exceed a threshold for closeness, the CCT can be constrained so that it is above a preset CCT that corresponds with sunrise or sunset. Other distance thresholds and the content of an image, as well as the brightness of the image, can be further employed in determining the CCT to employ.

Claims

1. A method of operating an auto white balance system of a camera of a mobile electronic device, the method comprising:

making a determination that a distance between the camera and a subject at least meets one of a number of predetermined distance thresholds;

responsive to the detecting, imposing a particular constraint upon the correlated color temperature that may be employed by the auto white balance in processing an image, the particular constraint being selected based at least in part upon the one of a number of predetermined distance thresholds; and

subjecting the image to the auto white balance system as constrained by the particular constraint.

2. The method of claim 1, further comprising:

making as the determination a determination that the distance between the camera and the subject is within a predetermined macro distance range; and

responsive thereto, imposing as the particular constraint upon the correlated color temperature a requirement that the correlated color temperature employed by the auto white balance be higher than that of a preset correlated color temperature for sunrise/sunset.

3. The method of claim 2, further comprising ignoring a dominant color of the image in the subjecting of the image to the auto white balance system.

4. The method of claim 1, further comprising:

making as the determination a determination that the distance between the camera and the subject is greater than a predetermined distance; and

responsive thereto, imposing as the particular constraint upon the correlated color temperature a requirement that the correlated color temperature employed by the auto white balance be higher than that of a preset correlated color temperature for cool fluorescent light.

5. The method of claim 4, further comprising:

determining that the image comprises at least one of;

a backlit scene,

a content that indicates a predominance of snow or sand, and

a line that delineates sky; and

responsive thereto, imposing as the particular constraint upon the correlated color temperature a requirement that the correlated color temperature employed by the auto white balance be at least 5000 degrees Kelvin.

6. A mobile electronic device comprising:

a processor apparatus;

an input apparatus comprising a camera module;

an output apparatus comprising a display;

one or more routines being stored on the mobile electronic device which, when executed on a processor of the mobile electronic device, cause the mobile electronic device to operate an auto white balance system including operations that comprise;

making a determination that a distance between the camera and a subject at least meets one of a number of predetermined distance thresholds;

responsive to the detecting, imposing a particular constraint upon the correlated color temperature that may be employed by the auto white balance in processing an image, the particular constraint being selected based at least in part upon the one of a number of predetermined distance thresholds; and

subjecting the image to the auto white balance system as constrained by the particular constraint.

7. The mobile electronic device of claim 6 wherein the operations further comprise:

making as the determination a determination that the distance between the camera and the subject is within a predetermined macro distance range; and

responsive thereto, imposing as the particular constraint upon the correlated color temperature a requirement that the correlated color temperature employed by the auto white balance be higher than that of a preset correlated color temperature for sunrise/sunset.

8. The mobile electronic device of claim 7 wherein the operations further comprise ignoring a dominant color of the image in the subjecting of the image to the auto white balance system.

9. The method of claim 6 wherein the operations further comprise:

making as the determination a determination that the distance between the camera and the subject is greater than a predetermined distance; and

responsive thereto, imposing as the particular constraint upon the correlated color temperature a requirement that the correlated color temperature employed by the auto white balance be higher than that of a preset correlated color temperature for cool fluorescent light.

10. The method of claim 9 wherein the operations further comprise:

determining that the image comprises at least one of;

a backlit scene,

a content that indicates a predominance of snow or sand, and

a line that delineates sky; and

responsive thereto, imposing as the particular constraint upon the correlated color temperature a requirement that the correlated color temperature employed by the auto white balance be at least 5000 degrees Kelvin.