Electronic blur correction device and electronic blur correction method

Abstract

In an electronic blur correction device, imaging for a time-division exposure time is repeated m times (m is an integer of 2 or more), captured images are amplified by a factor of m to obtain a plurality of time-divided images, and an image for which blur is corrected is generated from the plurality of time-divided images. Here, the time-division exposure time is an exposure time that is obtained by dividing a proper exposure time by m and is shorter than a blur tolerable limit exposure time.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

These and other features, aspects, and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:

FIG. 1 is a block diagram showing an electric system of a digital camera according to a preferred embodiment to which the present invention is applied;

FIG. 2 is a diagram showing the structure of an image pickup device 1 of the embodiment;

FIG. 3 is a block diagram showing the details of a gain control amplifier AMP of the embodiment;

FIG. 4 is a main flowchart showing the operation of the digital camera of the embodiment;

FIG. 5 is a flowchart showing blurred image correction and recording in the digital camera of the embodiment;

FIG. 6 is a flowchart showing the operation of a blurred image correction subroutine in the digital camera of the embodiment;

FIG. 7 is a timing chart showing a shooting operation of the digital camera of the embodiment;

FIG. 8 is a block diagram showing an alternative example of the gain control amplifier AMP in the digital camera of the embodiment; and

FIG. 9 is a table showing the relationship among input signal, ISO sensitivity, and gain in the gain control amplifier AMP of the digital camera of the embodiment.

Claims

1. An electronic blur correction device comprising: an exposure time computing part for computing an exposure time;a time-division exposure time computing part for computing a time-division exposure time that is shorter than a predetermined blur tolerable limit exposure time and is 1/m (m is an integer) of the exposure time;a time-division imaging part for performing time-division imaging for the time-division exposure time plural times;a first amplifier part for amplifying the images captured by the time-division imaging part by a factor of m;a blur compensation part for compensating for mutual blurring of a plurality of the time-divided images amplified by the factor of m; andan image synthesis part for combining the plurality of the time-divided images the mutual blurring of which are compensated for by the blur compensation part.

2. The electronic blur correction device according to claim 1 wherein the time-division exposure time is obtained by dividing the exposure time by the integral value m, which m is either of integral values in the immediate neighborhood of a value obtained by dividing the exposure time by the blur tolerable limit exposure time.

3. The electronic blur correction device according to claim 2 wherein the integral value m is an integral value obtained by rounding up the fractional part of the divided value.

4. The electronic blur correction device according to claim 1 further comprising: an ISO sensitivity setting part for setting an ISO sensitivity; anda second amplifier part for amplifying an image signal generated in an image pickup device by a gain determined according to the ISO sensitivity.

5. The electronic blur correction device according to claim 4 wherein the first amplifier and the second amplifier are combined as one unit.

6. An electronic blur correction device comprising: an exposure time setting part for setting an exposure time computed as the optimum exposure based on a subject brightness or an exposure time manually entered by a photographer;a time-division exposure time computing part for dividing the exposure time by a limit exposure time for which hand shakes are negligible and dividing the exposure time by an integral value close to the dividing result to compute a time-division exposure time;a time-division imaging part for performing time-division imaging for the time-division exposure time plural times; andan image generation part for generating an image from which blur is removed based on a plurality of time-divided images captured by the time-division imaging part.

7. The electronic blur correction device according to claim 6 wherein a value larger than the divided value is selected as the integral value from predetermined integral values.

8. The electronic blur correction device according to claim 6 wherein the image generation part obtains the blur-removed image in every period of the time-division exposure time and combines the blur-removed images.

9. The electronic blur correction device comprising: an exposure time setting part for setting an exposure time computed as an optimum exposure based on a subject brightness or an exposure time manually entered by a photographer;a time-division exposure time computing part for computing a time-division exposure time that is shorter than a predetermined blur tolerable limit exposure time and is 1/m (m is an integer) of the exposure time;a time-division imaging part for performing time-division imaging for the time-division exposure time plural times;a first amplifier part for amplifying an image captured by the time-division imaging part by a factor of m; andan image generation part for generating an image from which blur is removed based on the plurality of time-divided images amplified by the factor of m.

10. The electronic blur correction device according to claim 6 further comprising: an ISO sensitivity setting part for setting an ISO sensitivity; anda second amplifier part for amplifying an image signal generated in an image pickup device by a gain determined according to the ISO sensitivity.

11. The electronic blur correction device according to claim 10 wherein the first amplifier and the second amplifier are combined as one unit.

12. An electronic blur correction method comprising: computing a proper exposure time;computing a time-division exposure time by dividing the exposure time by an integer m, the time-division exposure time being shorter than a blur tolerable limit exposure time;performing time-division imaging for the time-division exposure time plural times;amplifying image signals obtained by the time-division imaging by a factor of m to obtain a plurality of image signals amplified by the factor of m; andusing the plurality of image signals amplified by the factor of m to generate an image for which blur is corrected.