PRODUCING AN EXTENDED DYNAMIC RANGE DIGITAL IMAGE

• US 20080025634A1
• Filed: 07/27/2006
• Published: 01/31/2008
• Est. Priority Date: 07/27/2006
• Status: Active Grant

• Current Assignee: Monument Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Eastman Kodak Company
• Inventors: Border, John N., Morales, Efrain O.
• Granted Patent: US 7,756,330 B2
• Time in Patent Office: Days
• US Class Current: 382/274
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 25/447 by preserving the colour pattern with or without loss of information
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/57 Control of the dynamic range
• CPC Class Codes: H04N 3/1562 for selective scanning, e.g. windowing, zooming
• CPC Class Codes: H04N 5/20 Circuitry for controlling amplitude response

Abstract

A method of producing a digital image with extended dynamic range, includes capturing at least a first full resolution digital image of a scene; combining pixels of a first full resolution digital image to produce a lower resolution digital image identifying dark regions in a first full resolution digital image and replacing the dark regions in the full resolution image with corresponding regions from the brighter, lower resolution image to thereby provide a digital image with extended dynamic range.

Claims

1. A method of producing a digital image with extended dynamic range, comprising:

a. capturing at least a first resolution digital image of a scene;

b. combining pixels of the first resolution digital image to produce a second digital image which is brighter with lower resolution;

c. identifying dark regions in the first resolution digital image; and

d. replacing dark regions in the first resolution digital image with corresponding regions from the second digital image to thereby provide a third digital image with extended dynamic range.

2. The method of claim 1 wherein the first resolution digital image is captured and stored in memory and the second digital image is produced from the stored first resolution digital image.

3. The method of claim 1 wherein at least one first resolution digital image is captured by an image sensor and the second digital image is provided from a second capture of the scene with combined pixels.

4. The method of claim 3 wherein pixels are combined by binning the charge from the pixels, by averaging the voltages produced by the pixels, or by first converting the pixel values to digital numbers and then combining the digital numbers, or combinations thereof.

5. The method of claim 4 wherein the voltages are averaged by first charging capacitors to the voltages produced by the pixels and then connecting the capacitors together to average the voltages, with the capacitors being of equal sizes to perform a simple average or of differing sizes to perform a weighted average.