Method and apparatus for reducing shutter lag in a digital imaging device

• US 7,620,304 B2
• Filed: 04/24/2006
• Issued: 11/17/2009
• Est. Priority Date: 04/24/2006
• 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: Larner, Joel B., Hofer, Gregory V.
• Primary Examiner(s): MAHONEY, CHRISTOPHER E
• Application Number:
  US11/410,703
• Publication Number:
  US 20070248341A1
• Time in Patent Office: 1,303 Days
• Field of Search: 396/130, 396/52, 348/208.12, 348/352
• US Class Current: 396/52
• CPC Class Codes: G03B 15/00 Special procedures for taking photographs; Apparatus therefor
• CPC Class Codes: G03B 2217/005 Blur detection
• CPC Class Codes: G03B 7/00 Control of exposure by setting shutters, diaphragms or filters, separately or conjointly control of exposure in television cameras by means of circuitry influencing the optical part of the camera H04N23/75
• CPC Class Codes: G03B 7/14 setting of both shutter and diaphragm aperture being effected so as to give the optimum compromise between depth of field and shortness of exposure

Abstract

A digital imaging device, such as a digital camera, minimizes shutter lag by determining some capture parameters, such as focus and exposure settings, before a user of the device has indicated that a photograph is to be taken. The parameters are updated when the device becomes substantially still before the indication that a photograph is to be taken.

Claims

1. A method of reducing shutter lag, comprising:

at a time before an indication that a photograph is to be taken imminently, selecting at least one capture parameter of a digital imaging device when it is determined that the digital imaging device is substantially still; and

locking the at least one capture parameter so long as the digital imaging device remains substantially still; and

when an indication that a photograph is to be taken imminently is received with the capture parameter locked, determining whether a photographic subject has moved since the capture parameter was selected before the indication was received; and

re-selecting at least one capture parameter if the subject has so moved.

2. The method of claim 1, wherein the selecting at least one capture parameter further comprises one or more of performing automatic focus and determining at least one exposure setting.

3. The method of claim 1, wherein the determination that the digital imaging device is substantially still is based on a signal from a motion sensing module.

4. The method of claim 1, wherein the determination that the digital imaging device is substantially still is made based on analysis of preliminary photographs.

5. The method of claim 1, wherein the indication that a photograph is to be taken imminently is the reaching of an S1 state.

6. The method of claim 1, further comprising:

before an indication that a photograph is to be taken imminently, re-selecting the at least one capture parameter when it is determined that the digital imaging device has moved since the at least one capture parameter was last selected and that the digital image device has once again become substantially still.

7. The method of claim 1, wherein determining whether the photographic subject has moved further comprises comparing a reference image taken before the indication was received with a current image taken after the indication is received.

8. The method of claim 1, wherein the digital imaging device is a camera.

9. A digital imaging device, comprising:

a shutter button having an S1 position and an S2 position;

memory; and

logic, the logic configured to

sense motion of the digital imaging device before S1 is reached;

determine, based on the sensed motion, that the digital imaging device is substantially still;

select at least one capture parameter upon determining that the digital imaging device is substantially still; and

store in the memory an indication that the at least one capture parameter has been selected;

when the S1 position is reached and the indication has been stored in memory that the at least one capture parameter has been selected;

determine that the digital imaging device has not moved since the at least one capture parameter was selected before S1 was reached;

determine that a photographic subject has not moved since the at least one capture parameter was selected before S1 was reached;

detect that the S2 position has been reached; and

upon these determinations, take a final photograph without re-determining the at least one capture parameter.

10. The digital imaging device of claim 9, further comprising a lens that projects an image of a scene onto a sensor, the lens being automatically focusable, and wherein the at least one capture parameter comprises a focus setting for the lens.

11. The digital imaging device of claim 9, and wherein the at least one capture parameter comprises an exposure setting.

12. The digital imaging device of claim 9, wherein the digital imaging device is a camera.

13. The digital imaging device of claim 9, wherein the logic senses motion of the digital imaging device by analyzing preliminary photographs.

14. The digital imaging device of claim 9, further comprising a motion sensing module that produces a signal indicating motion of the digital imaging device, and wherein the logic senses motion of the digital imaging device by monitoring the motion indicating signal.

15. The digital imaging device of claim 9, the logic further configured to, before the S1 position is reached:

determine that that digital imaging device has moved and once again become substantially still; and

upon the determination that the digital imaging device has moved and once again become substantially still, re-determine the at least one capture parameter.

16. A digital camera, comprising:

an electronic array light sensor;

a lens that projects an image of a scene onto the electronic array light sensor;

a shutter button having an S1 and an S2 position;

logic, the logic configured to, before the S1 position is reached,

sense motion of the camera;

perform automatic focus of the lens when it is determined, based on the sensed motion, that the camera is substantially still; and

re-perform automatic focus only upon a determination that the camera has moved since automatic focus was last performed and that the camera has once again become substantially still;

after the S1 position is reached, take a final photograph without re-performing automatic focus upon a determination that;

automatic focus was performed before S1 was reached;

the camera has not substantially moved since automatic focus was performed before S1 was reached; and

a photographic subject has not substantially moved since automatic focus was performed before S1 was reached; and

the S2 position has been reached.

17. The camera of claim 16, the logic further configured to, after the S1 position is reached, take a final photograph without re-performing automatic focus upon a determination that:

automatic focus was performed before S1 was reached; and

the camera has not substantially moved since automatic focus was performed before S1 was reached; and

the S2 position has been reached.