IMAGE CAPTURING DEVICE, IMAGE CAPTURING METHOD, AND STORAGE MEDIUM HAVING STORED THEREIN IMAGE CAPTURING PROGRAM

• US 20100209009A1
• Filed: 02/16/2010
• Published: 08/19/2010
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: MATSUNAGA, Kazuhisa
• Granted Patent: US 8,310,553 B2
• Time in Patent Office: Days
• US Class Current: 382/224
• 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 23/6845 by combination of a plurality of images sequentially taken
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 23/951 by using two or more images to influence resolution, frame rate or aspect ratio
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements

Abstract

A digital camera carries out the following steps. The digital camera acquires one image photographed with a high sensitivity for subject-blur suppression, four images of a first group consecutive in a time series photographed with an ordinary exposure time, and four images of a second group consecutive in a time series photographed with an exposure time shorter than the ordinary exposure time for multiplane addition. Then, the digital camera extracts, from among the images photographed with the ordinary exposure time, an image for which blur caused by hand movement is minimum, and if no image blur has occurred and if blur caused by hand movement is less than a predetermined value, selects the image. The digital camera selects the image for subject-blur suppression if image blur has occurred for the extracted image. Also, the digital camera generates a new image by carrying out multiplane addition of images for multiplane addition if blur caused by hand movement has occurred for the extracted image.

Claims

1. An image capturing device, comprising:

an image capturing means for acquiring images of a first group consecutive in time in which a subject is photographed for a first exposure time, and images of a second group consecutive in time in which a subject is photographed for a second exposure time;

a hand-blur determination means for determining whether blur caused by hand movement has occurred during acquisition of the images of the first group by way of the image capturing means;

an image-blur determination means for determining whether image blur of a subject has occurred during acquisition of the images of the first group by way of the image capturing means; and

a selection means for selecting either an image acquired from the images of the first group or an image acquired from the images of the second group, in accordance with a determination result by the hand-blur determination means and a determination result by the image-blur determination means.

2. An image capturing device as set forth in claim 1, wherein

the selection means selects an image acquired from the images of the second group in a case where the image-blur determination means determines that no image blur has occurred and the hand-blur determination means determines that blur caused by hand movement has occurred.

3. An image capturing device as set forth in claim 1, further comprising an image processing means for synthesizing the images of the second group to generate a new image, wherein

the image acquired from the images of the second group is the new image.

4. An image capturing device as set forth in claim 1, wherein

the selection means selects an image acquired from the images of the first group in a case where the image-blur determination means determines that no image blur has occurred and the hand-blur determination means determines that no blur caused by hand movement has occurred.

5. An image capturing device as set forth in claim 1, further comprising a calculation means for obtaining a projective transformation matrix from images consecutive in time in the images of the first group, and calculating a size of a motion vector from the projective transformation matrix, wherein

the image-blur determination means determines whether image blur has occurred for the image for which the size of a motion vector for each pixel calculated by the calculation means is minimum.

6. An image capturing device as set forth in claim 5, wherein

the hand-blur determination means determines whether blur caused by hand movement has occurred for the image for which the size of a motion vector is minimum, based on whether the size of the motion vector exceeds a predetermined threshold.

7. An image capturing device as set forth in claim 1, wherein:

the image capturing means acquires a third image in which a subject is photographed with a higher sensitivity than the sensitivity with which either images of a first group is photographed or images of a second group is photographed, and

the selection means selects any one of the images acquired from the images of the first group, the images of second group, and the third image, and if image blur is determined to have occurred by the image-blur determination means, selects the third image.

8. An image capturing device as set forth in claim 1, wherein the second exposure time is shorter than the first exposure time.

9. An image capturing method, comprising:

an acquiring step of acquiring images of a first group consecutive in a time series photographed with a first exposure time of a subject, and images of a second group consecutive in a time series photographed with a second exposure time of a subject;

a hand-blur determining step of determining whether blur caused by hand movement has occurred during acquisition of the images of the first group;

an image-blur determining step of determining whether image blur has occurred during acquisition of the images of the first group; and

a selecting step of selecting either an image acquired from the images of the first group or an image acquired from the images of the second group in accordance with respective determination results of the hand-blur determining step and of the image-blur determining step.

10. A storage medium having stored therein an image capturing program enabling a computer of an image capturing device to carry out:

an acquiring step of acquiring images of a first group consecutive in a time series photographed with a first exposure time of a subject, and images of a second group consecutive in a time series photographed with a second exposure time of a subject;

a hand-blur determining step of determining whether blur caused by hand movement has occurred during acquisition of the images of the first group;

an image-blur determining step of determining whether image blur has occurred during acquisition of the images of the first group; and

a selecting step of selecting either an image acquired from the images of the first group or an image acquired from the images of the second group in accordance with respective determination results of the hand-blur determining step and of the image-blur determining step.