Apparatus and method for reducing image blur in a digital camera

• US 7,787,015 B2
• Filed: 04/10/2007
• Issued: 08/31/2010
• Est. Priority Date: 01/08/2003
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Stavely, Donald J.
• Primary Examiner(s): Chan, Jason
• Assistant Examiner(s): Giles, Nicholas G
• Application Number:
  US11/786,210
• Publication Number:
  US 20070188617A1
• Time in Patent Office: 1,239 Days
• Field of Search: 348/208.16, 348/208.1, 348/208.2, 348/208.12, 348/208.99
• US Class Current: 348/208.1
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/684 performed by controlling the image sensor readout, e.g. by controlling the integration time

Abstract

A digital camera delays the capture of a digital image after image capture has been requested until the motion of the digital camera satisfies a motion criterion. The digital camera thereby reduces image blur that would otherwise occur due to camera motion.

Claims

1. A digital camera, comprising:

an imaging module configured to convert optical images to digital images and further configured to produce a series of digital preview frames in a video preview mode;

an input control to initiate capture of a digital image by the imaging module; and

processing logic configured to determine motion of the digital camera,

the processing logic being configured to delay capture of the digital image until the determined motion of the digital camera satisfies a motion criterion, and the processing logic being configured to perform an automated image capture adjustment operation;

wherein the performance of the automated image capture adjustment operation and the determination of the motion of the digital camera by the processing logic are respectively based on picture element values in different respective mutually exclusive regions of each of respective ones of the digital preview frames, wherein for each of the respective ones of the digital preview frames, picture element values from a central window region of the digital preview frame are used for performing the automated image capture adjustment operation and picture element values from a peripheral motion measurement region of the digital preview frame outside the central window region are used for determining the motion of the digital camera.

2. The digital camera of claim 1, wherein the processing logic is configured to apply a window function that attenuates an edge sub-region of the peripheral motion measurement region of each of the respective ones of the digital preview frames.

3. The digital camera of claim 1, wherein the processing logic is configured to determine a horizontal component of the motion of the digital camera based on a horizontally oriented set of picture elements in the peripheral motion measurement region of each of the respective ones of the digital preview frames.

4. The digital camera of claim 1, wherein the processing logic is configured to determine a vertical component of the motion of the digital camera based on a vertically oriented set of picture elements in the peripheral motion measurement region of each of the respective ones of the digital preview frames.

5. The digital camera of claim 1, wherein the processing logic is configured to compute horizontal and vertical motion components of the motion of the digital camera from different respective sets of picture elements in the peripheral motion measurement region of each of the respective ones of the digital preview frames.

6. The digital camera of claim 1, further comprising at least one accelerometer.

7. The digital camera of claim 1, further comprising at least one gyroscope.

8. The digital camera of claim 1, wherein the processing logic is configured to determine the motion of the digital camera based on the square root of the sum of a horizontal motion component squared and a vertical motion component squared.

9. The digital camera of claim 1, wherein the processing logic is configured to determine the motion of the digital camera based on the sum of the absolute value of a horizontal motion component and the absolute value of a vertical motion component.

10. The digital camera of claim 1, wherein the automated image capture adjustment operation that the control logic is configured to perform is an autofocus operation, and the central window region corresponds to an autofocus window.

11. The digital camera of claim 1, wherein the automated image capture adjustment operation that the control logic is configured to perform is an autoexposure operation, and the central window region corresponds to an autoexposure window.

12. The digital camera of claim 1, wherein in the process of performing the automated image capture adjustment operation, the processing logic determines the respective central window sub-region of each of respective ones of the digital preview frames.

13. A method for reducing image blur in a digital camera, comprising:

acquiring a series of digital preview frames in a video preview mode of the digital camera;

determining motion of the digital camera in response to a first input signal; and

delaying capture of a digital image, following receipt of a second input signal, until the determined motion of the digital camera satisfies a motion criterion; and

performing an automated image capture adjustment operation;

wherein the performing of the automated image capture adjustment operation and the determining of the motion of the digital camera are respectively based on picture element values in different respective mutually exclusive regions of each of respective ones of the digital preview frames, wherein for each of the respective ones of the digital preview frames, picture element values from a central window region of the digital preview frame are used for performing the automated image capture adjustment operation and picture element values from a peripheral motion measurement region of the digital preview frame outside the central window region are used for measuring the motion of the digital.

14. The method of claim 13, wherein the performing comprises performing an autofocus operation, and the central window region coincides with an autofocus region of each digital preview frame with respect to which the autofocus operation is performed.

15. The method of claim 13, further comprising:

applying a window function that attenuates an edge sub-region of the peripheral motion measurement region of each of the respective ones of the digital preview frames.

16. The method of claim 13, wherein the determining comprises determining a horizontal component of the motion of the digital camera based on a horizontally oriented set of picture elements in the peripheral motion measurement region of each of the respective ones of the digital preview frames.

17. The method of claim 13, wherein the determining comprises determining a vertical component of the motion of the digital camera based on a vertically oriented set of picture elements in the peripheral motion measurement region of each of the respective ones of the digital preview frames.

18. The method of claim 13, wherein the determining comprises computing horizontal and vertical motion components of the motion of the digital camera from different respective sets of picture elements in the peripheral motion measurement region of each of the respective ones of the digital preview frames.

19. The method of claim 13, further comprising measuring the motion of the digital camera using at least one accelerometer.

20. The method of claim 13, further comprising measuring the motion of the digital camera using at least one gyroscope.

21. A digital camera comprising:

means for converting optical images to digital images and for producing a series of digital preview frames in a video preview mode;

means for initiating capture of a digital image;

means for tracking motion of the digital camera responsive to the means for initiating capture of a digital image, an output of the means for tracking motion of the digital camera indicating the quantity of motion of the digital camera as a function of time; and

means for delaying capture of the digital image until the output of the means for tracking motion of the digital camera satisfies a motion criterion; and

means for performing an automated image capture adjustment operation;

wherein the performing means performs the automated image capture adjustment operation and the tracking means tracks the motion of the digital camera based on picture element values in different respective mutually exclusive regions of each of respective ones of the digital preview frames, wherein for each of the respective ones of the digital preview frames, picture element values from a central window region of the digital preview frame are used by the performing means for performing the automated image capture adjustment operation and picture element values from a peripheral motion measurement region of the digital preview frame outside the central window region are used by the tracking means for tracking the motion of the digital camera.