Method for estimating camera settings adaptively

• US 7,403,707 B2
• Filed: 07/28/2005
• Issued: 07/22/2008
• Est. Priority Date: 07/28/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Nayar, Shree K., Raskar, Ramesh, Agrawal, Amit, Li, Yuanzhen
• Primary Examiner(s): Perkey; W. B.
• Assistant Examiner(s): Fenwick; Warren K
• Application Number:
  US11/191,681
• Publication Number:
  US 20070025720A1
• Time in Patent Office: 1,090 Days
• Field of Search: 396/128, 396/213, 348/207.99, 348/297
• US Class Current: 396/213
• CPC Class Codes: G03B 7/16 in accordance with both the intensity of the flash source and the distance of the flash source from the object, e.g. in accordance with the "guide number" of the flash bulb and the focusing of the camera
• CPC Class Codes: G03B 7/28 Circuitry to measure or to take account of the object contrast
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: G06V 10/60 relating to illumination properties, e.g. using a reflectance or lighting model
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls

Abstract

A camera is configured to adaptively determine camera settings. The camera includes a plurality of sensors elements configured to acquire a current image of a scene according to a current set of camera settings. A number of sensor elements having a set of desirable properties is measured. Then, a next set of camera settings that maximize an overall number of sensor elements having the set of desirable properties is determined to acquire a next better image.

Claims

1. A method for adaptively determining a set of camera settings, comprising the steps of:

acquiring an initial image of a scene with a camera including a plurality of sensor elements, the camera having an initial set of camera settings while acquiring the initial image;

measuring, from the initial image, a number of pixels in the initial image having a set of desirable properties;

estimating, for each of a plurality of next sets of camera settings, a set of estimated properties for each pixel in an estimated image;

selecting the next set of camera settings that maximizes an overall number of pixels having the set of desirable properties; and

replacing the initial set of camera settings with the next set of camera settings.

2. The method of claim 1, further comprising:

acquiring a next image of the scene with the camera having the next set of camera settings.

3. The method of claim 2, further comprising:

measuring, from the next image, a number of pixels in the next image having the set of desirable properties; and

selecting another next set of camera settings that maximizes a cumulative number of pixels having the set of desirable properties.

4. The method of claim 1, in which the acquiring, measuring, estimating, selecting and replacing is repeated until the number of pixels having the set of desirable properties exceeds a threshold.

6. The method of claim 1, in which the initial set of camera settings and the next set of camera settings includes a flash power setting and a shutter exposure time setting.

7. The method of claim 1, in which the set of desirable properties includes an intensity over a threshold.

8. The method of claim 1, in which the set of desirable properties includes a signal-to-noise ratio over a threshold.

5. A camera configured to adaptively determine camera settings, comprising:

a set of camera settings;

a plurality of sensors elements configured to acquire an initial image of a scene according to an initial set of camera settings;

means for measuring, from the initial image, a number of pixels in the initial image having a set of desirable properties;

means for estimating, for each of a plurality of next sets of camera settings, a set of estimated properties for each pixel in an estimated image; and

means for selecting a next set of camera settings that maximizes an overall number of pixels having the set of desirable properties.