HAND JITTER REDUCTION SYSTEM FOR CAMERAS

Abstract

A camera system in normal mode and hand jitter reduction (hjr) mode may comprise generating a first exposure time-gain product by multiplying the normal mode exposure time with the normal mode gain. It may further comprise modifying the normal mode exposure time and gain and multiplying these modified parameters to generate a second exposure time-gain product for a hjr mode that reduces the difference between the first exposure time-gain product and the second exposure time-gain product. To reduce the difference the normal mode frame rate may also be modified. Operation of a camera in normal mode may be in response to a sensed light level being above a threshold. The hjr mode may be selected by the user while the camera is operating. The hjr mode may be used in response to a sensed light level being lower than the threshold.

Description

BRIEF DESCRIPTION OF DRAWINGS

Various configurations are illustrated by way of example, and not by way of limitation, in the accompanying drawings.

FIG. 1 is a block diagram illustrating one configuration of a digital imaging process.

FIG. 2 is a block diagram illustrating the functionality of one configuration of one front end image processing module in a digital image processing system.

FIG. 3 is a block diagram illustrating the functionality of another configuration of a front end image processing module in a digital image processing system.

FIG. 4A is a graph illustrating exposure time versus light level for normal mode.

FIG. 4B is a graph illustrating gain versus light level for normal mode.

FIG. 5A is a graph illustrating exposure time versus light level for hand jitter reduction mode.

FIG. 5B is a graph illustrating gain versus light level hand jitter reduction mode.

FIG. 6 is a flowchart illustrating a method of generating modified auto-exposure parameters.

A flowchart illustrating how to operate a camera system in normal mode and hand jitter reduction mode is in FIG. 7.

FIG. 8 is a flowchart illustrating the modification of auto-exposure parameters in a camera system in hand jitter reduction mode.

Claims

1. A device comprising: means for identifying a light level in at least one captured image;means for detecting selection of hand jitter reduction mode;means for dynamically selecting hand jitter mode modified auto-exposure parameters to image process the at least one captured image, the hand jitter reduction mode unmodified auto-exposure parameters having an exposure time-gain product that corresponds to an exposure time-gain product of the normal mode modified auto-exposure parameters.

2. The device of claim 1, wherein the modified auto-exposure parameters comprise gain and exposure time.

3. The device of claim 1, wherein the modified auto-exposure parameters further comprise frame rate.

4. A computer-readable medium storing a set of instructions, wherein the set of instructions when executed by one or more processors comprises: means for identifying a light level in at least one captured image;means for detecting selection of hand jitter reduction mode;means for dynamically selecting hand jitter mode modified auto-exposure parameters to image process the at least one captured image, the hand jitter reduction mode unmodified auto-exposure parameters having an exposure time-gain product that corresponds to an exposure time-gain product of the normal mode modified auto-exposure parameters.

5. The computer-readable medium of claim 4, wherein the modified auto-exposure parameters comprise gain and exposure time.

6. The computer-readable medium of claim 4, wherein the modified auto-exposure parameters further comprise frame rate.

7. A device that performs image processing comprising a hand jitter reduction mode having a means for detecting a light level and means responsive to the detected light level for reducing hand jitter, the reducing of the hand jitter including single frame noise reduction when the light level is in a first range and multiple frame noise reduction when the light level is in a second range.

8. The device of claim 7, wherein the reduction of hand jitter includes modified auto-exposure parameters.

9. The device of claim 8, wherein the modified auto-exposure parameters are gain, exposure time, and frame rate.

10. The device of claim 7, wherein the multiple frame noise reduction reduces blurriness through multiple frame registration.

11. The device of claim 7, wherein the single frame noise reduction is bayer filtering.

12. The device of claim 7, wherein image processing in hand jitter reduction mode occurs when the detected light level is above a minimum amount of light level used when removing blur in a digital picture.

13. The device of claim 11, wherein the detected light level is mapped to an auto-exposure index.

14. The device of claim 7, wherein the first range a first frame rate is reaches a maximum, and in response the first frame rate is lowered to generate a second frame rate to increase an exposure time.

15. The device of claim 14, wherein a gain is lowered in response to the increased exposure time.

16. The device of claim 7, wherein the second range comprises two ranges, a third range and a fourth range.

17. The camera device of claim 16, wherein a second boundary between the third range and the fourth range is determined by the light level not meeting a luma target.

18. The device of claim 17, wherein a digital gain is applied in the third range and the fourth range.

19. The device of claim 7, wherein the first range is between boundary_a and boundary_b.

20. The device of claim 7, wherein the second range is beyond boundary_b.

21. An integrated circuit adapted to be coupled to an image sensor responsive to modified auto-exposure parameters generated by the integrated circuit to reduce hand jitter of captured digital images in hand jitter reduction mode, comprising: means for identifying at least one captured image;means for detecting selection of hand jitter reduction mode;means for identifying a light level associated with the at least one captured image;means for mapping the light level to a corresponding gain and exposure time in a normal mode;means for computing a first exposure time-gain product from the corresponding gain and exposure time; andmeans for generating modified auto-exposure parameters in response to the computation of the exposure time-gain product, to reduce hand jitter.

22. The device of claim 21, wherein the means for generating modified auto-exposure parameters in response to the computation of the exposure time-gain product comprises modifying the gain and exposure time.

23. The device of claim 22, wherein the means for generating modified auto-exposure parameters further comprises computation of a second exposure time-gain product.

24. The device of claim 21, wherein the integrated circuit is an MSM™.

25. A method of generating modified auto-exposure parameters comprising: capturing at least one frame after a snapshot;entering hjr mode;associating a detected light level with unmodified auto-exposure parameters;retrieving an exposure time and gain from memory;calculating a first exposure-time gain product from the retrieved exposure time and gain; andgenerating modified auto-exposure parameters based on the first exposure-time gain product.

26. The method of claim 25, wherein the generating modified auto-exposure parameters based on the first exposure-time gain product includes multiplying, subtracting, adding, and dividing the retrieved exposure time and gain.

27. The method of claim 25, wherein the modified auto-exposure parameters comprise gain and exposure time.

28. The method of claim 27, wherein the modified auto-exposure parameters further comprise frame rate.