IMAGE-CAPTURING DEVICE, AND IMAGE COMBINATION PROGRAM

• US 20120013737A1
• Filed: 07/13/2011
• Published: 01/19/2012
• Est. Priority Date: 07/14/2010
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: UMEYAMA, Kazuya, SHINODA, Tomotaka
• Granted Patent: US 9,509,911 B2
• Time in Patent Office: Days
• US Class Current: 348/135
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene

Abstract

An image-capturing device includes: an image-capturing unit that captures an image of a photographic subject; a selection unit that selects, as a reference image, a single image from among a plurality of images that have been captured in succession by the image-capturing unit; a calculation unit that calculates an amount of positional deviation between the reference image and each of the plurality of images other than the reference image; and a generation unit that generates a combined image by positionally aligning and then combining the reference image and those ones of the plurality of images whose amounts of positional deviation are less than or equal to a predetermined amount of deviation. The selection unit selects the reference image so that the number of images for which the amount of positional deviation is less than or equal to the predetermined amount of deviation becomes large.

Claims

1. An image-capturing device, comprising:

an image-capturing unit that acquires an image by capturing an image of a photographic subject;

a selection unit that selects, as a reference image, a single image from among a plurality of images that have been captured in succession by the image-capturing unit;

a calculation unit that calculates an amount of positional deviation between the reference image selected by the selection unit and each of the plurality of images other than the reference image captured in succession by the image-capturing unit; and

a generation unit that generates a combined image by positionally aligning and then combining the reference image and those ones of the plurality of images whose amounts of positional deviation calculated by the calculation unit are less than or equal to a predetermined amount of deviation, wherein

the selection unit selects the reference image so that the number of images for which the amount of positional deviation is less than or equal to the predetermined amount of deviation becomes large.

2. An image-capturing device according to claim 1, wherein

the selection unit selects the reference image from among the plurality of images captured in succession by the image-capturing unit, after having excluded the image that was captured first and the image that was captured last from the plurality of images.

3. An image-capturing device according to claim 2, wherein:

if the number of the plurality of images captured in succession by the image-capturing unit is an odd number, the selection unit selects a single image positioned at the center when the plurality of images are arranged in time series as the reference image; and

if the number of the plurality of images captured in succession by the image-capturing unit is an even number, the selection unit selects either one of two images positioned at the center when the plurality of images are arranged in time series as the reference image.

4. An image-capturing device according to claim 3, wherein

if the number of the plurality of images captured in succession by the image-capturing unit is an even number, the selection unit selects, as the reference image, that one which was captured later of the two images positioned at the center when the plurality of images are arranged in time series.

5. An image-capturing device according to claim 1 wherein

from among the plurality of images captured in succession by the image-capturing unit, the selection unit selects an image whose maximum amount of deviation from other images is the smallest as the reference image.

6. An image-capturing device according to claim 5, wherein

if shaking is present in the selected reference image, the selection unit selects an image whose maximum amount of deviation from other images is the second smallest as a substitutional reference image.

7. An image-capturing device according to claim 1, wherein

the images that are captured by the image-capturing unit are images upon which hand shaking correction has been performed.

8. An image-capturing device that combines a plurality of images and obtains an image having an appropriate exposure determined according to a situation during image capture, comprising:

an image-capturing unit that acquires an image by capturing an image of a photographic subject;

a selection unit that selects, as a reference image, a single image from among a plurality of images that have been captured in succession by the image-capturing unit;

a calculation unit that calculates an amount of positional deviation between the reference image selected by the selection unit and each of the plurality of images other than the reference image captured in succession by the image-capturing unit;

a generation unit that generates a combined image by positionally aligning and then combining the reference image and subject images that are ones of the plurality of images and whose amounts of positional deviation calculated by the calculation unit are less than or equal to a predetermined amount of deviation; and

a processing execution unit that, if the image having the appropriate exposure cannot be obtained by combination of the reference image and the subject images, executes processing for exposure correction upon the combined image with varying the processing according to the total number of the reference image and the subject images combined by the generation unit.

9. An image-capturing device according to claim 8, wherein

on the basis of the number of the plurality of images captured in succession by the image-capturing unit and the number of the subject images that have been used for combination, the processing execution unit executes the processing for exposure correction upon the combined image so as to make an exposure of the combined image and an exposure of the image that would be obtained by combining all of the plurality of images agree with one another.

10. An image-capturing device according to claim 9, wherein

the processing execution unit applies digital gain to the combined image according to the number of the subject images so as to make the exposure of the combined image and the exposure of the image that would be obtained by combining all of the plurality of images agree with one another.

11. An image-capturing device according to claim 9, wherein

the processing execution unit performs additive combination of a certain number of copies of the combined image corresponding to the number of the subject images, while shifting them in mutually different directions by a predetermined amount, so as to make the exposure of the combined image and the exposure of the image that would be obtained by combining all of the plurality of images agree with one another.

12. An image-capturing device according to claim 9 wherein:

on the basis of the number of the plurality of images captured in succession by the image-capturing unit and the number of the subject images that have been used for combination, the processing execution unit calculates a gain amount required in order to make the exposure of the combined image and the exposure of the image that would be obtained by combining all of the plurality of images agree with one another,

if the required gain amount is less than or equal to a predetermined gain amount, the processing execution unit applies digital gain to the combined image according to the number of the subject images; and

if the required gain amount is greater than the predetermined gain amount, the processing execution unit performs additive combination of a certain number of copies of the combined image corresponding to the number of the subject images, while shifting them in mutually different directions by a predetermined amount.

13. An image combination program for causing a computer to execute:

an image-capturing step of acquiring images of a photographic subject captured in succession;

a selection step of selecting, as a reference image, a single image from among a plurality of images that have been captured in succession in the image-capturing step;

a calculation step of calculating an amount of positional deviation between the reference image selected in the selection step and each of the plurality of images other than the reference image captured in succession in the image-capturing step; and

a generation step of generating a combined image by positionally aligning and then combining the reference image and those ones of the plurality of images whose amounts of positional deviation calculated in the calculation step are less than or equal to a predetermined amount of deviation, wherein

in the selection step, the reference image is selected so that the number of images for which the amount of positional deviation is less than or equal to the predetermined amount of deviation becomes large.

14. An image combination program for combining a plurality of images and for obtaining an image having an appropriate exposure determined according to a situation during image capture, and for causing a computer to execute:

an image-capturing step of acquiring images of a photographic subject captured in succession;

a selection step of selecting, as a reference image, a single image from among a plurality of images that have been captured in succession in the image-capturing step;

a calculation step of calculating an amount of positional deviation between the reference image selected in the selection step and each of the plurality of images other than the reference image captured in succession in the image-capturing step;

a generation step of generating a combined image by positionally aligning and then combining the reference image and subject images that are ones of the plurality of images and whose amounts of positional deviation calculated in the calculation step are less than or equal to a predetermined amount of deviation; and

a processing execution step of, if the image having the appropriate exposure cannot be obtained by combination of the reference image and the subject images, executing processing for exposure correction upon the combined image with varying the processing according to the total number of the reference image and the subject images combined in the generation step.