Systems and methods of anti-aliasing with image stabilizing subsystems for cameras

• US 7,705,883 B2
• Filed: 10/28/2005
• Issued: 04/27/2010
• Est. Priority Date: 10/28/2005
• 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., Goris, Andrew C.
• Primary Examiner(s): Ho; Tuan
• Assistant Examiner(s): CAMARGO, MARLY S.B.
• Application Number:
  US11/261,086
• Publication Number:
  US 20070097220A1
• Time in Patent Office: 1,642 Days
• Field of Search: 348/208.99, 348/208.6, 348/208.4, 348/208.2, 348/208.5, 348/208.13, 348/335, 348/208.11, 348/222.1, 348/208.8, 345/611, 345/596, 382/269, 382/210, 382/263, 382/264
• US Class Current: 348/208.11
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

Systems and method for implementing anti-aliasing with image stabilizing subsystems for cameras are disclosed. In an exemplary embodiment the method may comprise characterizing motion of a camera, characterizing aliasing for an image being photographed by the camera, and moving at least one optical element in the camera during exposure of the image for both stabilizing and anti-aliasing the image.

Claims

1. A system comprising:

anti-aliasing logic generating a dither signal for anti-aliasing an image;

an image stabilizing subsystem generating an image stabilizing signal for stabilizing the image; and

at least one actuator drive operatively associated with at least one optical element in a camera, the at least one actuator drive moving the at least one optical element during exposure of the image according to a control signal based on a combination of the dither signal and the image stabilizing signal, and

wherein the control signal based on a combination of the dither signal and the image stabilizing signal is applied variably for short exposure times and for long exposure times.

2. The system of claim 1 wherein the dither signal is a high-frequency signal.

3. The system of claim 1 wherein the image stabilizing signal is a low-frequency signal.

4. The system of claim 1 wherein the image stabilizing signal is a null signal.

5. The system of claim 1 wherein the image stabilizing signal is combined with the dither signal and input to the at least one actuator drive as a control signal.

6. The system of claim 1 wherein the anti-aliasing logic characterizes a pre-image, the anti-aliasing logic generating the dither signal based at least in part on aliasing in the pre-image.

7. The system of claim 6 wherein the anti-aliasing logic generates the dither signal based in part on at least one of the following:

camera settings, user-preferences, and a scene being photographed.

8. The system of claim 1 wherein the actuator drive moves the at least one optical element in the camera during at least part of the exposure of the image.

9. The system of claim 8 wherein the actuator drive moves the at least one optical element a predetermined amount of time in at least one direction during exposure of the image.

10. A method comprising:

characterizing motion of a camera;

generating an image stabilizing signal based on motion of the camera;

characterizing aliasing for an image being photographed by the camera;

generating a dither signal based on aliasing for the image;

overlaying the dither signal and the image stabilizing signal to generate a control signal; and

moving at least one optical element in the camera during exposure of the image based on the control signal for both stabilizing and anti-aliasing the image, and

wherein the control signal is applied in diagonal-mode and follows camera motion based on exposure time.

11. The method of claim 10 wherein the at least one optical element responds to high-frequency input for anti-aliasing the image.

12. The method of claim 10 wherein the at least one optical element responds to low-frequency input for stabilizing the image.

13. The method of claim 10 further comprising multiplexing an image stabilizing signal and a dither signal for moving the at least one optical element in the camera during exposure of the image.

14. The method of claim 10 further comprising analyzing a pre-image for characterizing motion and aliasing.

15. The method of claim 10 wherein moving the at least one optical element is based in part on at least one of the following:

camera settings, user-preferences, and a scene being photographed.

16. The method of claim 10 wherein moving the at least one optical element in the camera is during only a part of the exposure of the image.

17. The method of claim 10 wherein moving the at least one optical element in the camera is for a predetermined amount of time and in at least one direction during the exposure of the image.

18. A camera system comprising:

image stabilizing means for characterizing motion of a camera;

anti-aliasing means for characterizing aliasing for an image being photographed by the camera; and

optical control means for moving at least one optical element in the camera during exposure of the image based on combined output from the image stabilizing means and anti-aliasing means, wherein the control signal based on a combination of the dither signal and the image stabilizing signal is applied variably for short exposure times and for long exposure times.

19. The camera system of claim 18 further comprising means for combining output from the image stabilizing means with output from the anti-aliasing means.

20. The camera system of claim 18 further comprising means for capturing at least one pre-image, wherein the image stabilizing means and the anti-aliasing means separately characterize the at least one pre-image.