IMAGE PROCESSING APPARATUS, ELECTRONIC CAMERA, AND MEDIUM STORING IMAGE PROCESSING PROGRAM

• US 20120008006A1
• Filed: 07/07/2011
• Published: 01/12/2012
• Est. Priority Date: 07/08/2010
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: MURAMATSU, Masaru
• Granted Patent: US 9,294,685 B2
• Time in Patent Office: Days
• US Class Current: 348/222.1
• CPC Class Codes: G06T 2207/10144 Varying exposure
• CPC Class Codes: G06T 2207/20208 High dynamic range [HDR] image processing
• CPC Class Codes: G06T 2207/20212 Image combination
• CPC Class Codes: G06T 5/92 based on global image properties
• CPC Class Codes: H04N 1/3871 the composed originals being of different kinds, e.g. low- and high-resolution originals
• CPC Class Codes: H04N 1/407 Control or modification of tonal gradation or of extreme levels, e.g. background level
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 5/202 Gamma control circuits for controlling camera response irrespective of the scene brightness H04N23/82

Abstract

In an image processing apparatus performing synthetic processing on N number of images (where N is an integer of two or larger) being captured from a same photographic scene under mutually different exposure conditions to generate a synthetic image with a higher dynamic range than the N number of images, obtaining the N number of images, and performing low-pass processing on at least one image among the N number of images to generate a low-pass image. Then, a weighting amount in the synthetic processing is decided based on the low-pass image, and the synthetic processing is performed on the N number of images according to the decided weighting amount to generate the synthetic image. Accordingly, a natural synthetic image with fewer changes in contrast, hue, and chroma is generated in a simple configuration when generating the synthetic image.

Claims

1. An image processing apparatus performing synthetic processing on N number of images, where N is an integer of two or larger, being captured from a same photographic scene under mutually different exposure conditions to generate a synthetic image with a higher dynamic range than the N number of images, the apparatus comprising:

an obtaining unit obtaining the N number of images;

a low-pass processing unit performing low-pass processing on at least one image among the N number of images to generate a low-pass image;

a decision unit deciding a weighting amount in the synthetic processing based on the low-pass image; and

an image synthesizing unit performing the synthetic processing on the N number of images according to the weighting amount to generate the synthetic image.

2. The image processing apparatus according to claim 1, wherein

the low-pass processing unit generates the low-pass image from an image with a smaller exposure amount under the exposure condition among the N number of images.

3. The image processing apparatus according to claim 1, further comprising

a gradation conversion processing unit performing predetermined gradation conversion processing on the low-pass image, wherein

the decision unit decides the weighting amount based on the low-pass image being performed the gradation conversion processing.

4. The image processing apparatus according to claim 3, further comprising

a setting unit setting a gradation conversion characteristic in the gradation conversion processing based on a user operation.

5. The image processing apparatus according to claim 3, further comprising

a setting unit setting a gradation conversion characteristic in the gradation conversion processing based on luminance information of the N number of images.

6. The image processing apparatus according to claim 1, wherein

the obtaining unit obtains three or more images as the N number of images, and generates the synthetic image by repeating the processes being performed by the low-pass processing unit, the decision unit, and the image synthesizing unit a plurality of times.

7. The image processing apparatus according to claim 2, wherein

the obtaining unit obtains three or more images as the N number of images, and generates the synthetic image by repeating the processes being performed by the low-pass processing unit, the decision unit, and the image synthesizing unit a plurality of times.

8. The image processing apparatus according to claim 3, wherein

the obtaining unit obtains three or more images as the N number of images, and generates the synthetic image by repeating the processes being performed by the low-pass processing unit, the decision unit, and the image synthesizing unit a plurality of times.

9. The image processing apparatus according to claim 4, wherein

the obtaining unit obtains three or more images as the N number of images, and generates the synthetic image by repeating the processes being performed by the low-pass processing unit, the decision unit, and the image synthesizing unit a plurality of times.

10. The image processing apparatus according to claim 5, wherein

the obtaining unit obtains three or more images as the N number of images, and generates the synthetic image by repeating the processes being performed by the low-pass processing unit, the decision unit, and the image synthesizing unit a plurality of times.

11. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 1, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

12. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 2, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

13. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 3, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

14. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 4, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

15. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 5, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

16. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 6, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

17. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 7, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

18. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 8, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

19. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 9, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

20. An electronic camera, comprising:

an image capturing unit capturing a same photographic scene under mutually different exposure conditions to generate a plurality of number of images; and

an image processing apparatus according to claim 10, wherein

the obtaining unit obtains the N number of images from the image capturing unit.

21. A non-transitory storage medium storing an image processing program which causes a computer to perform synthetic processing on N number of images, where N is an integer of two or larger, being captured from a same photographic scene under mutually different exposure conditions to generate a synthetic image with a higher dynamic range than the N number of images, the image processing program comprising:

an obtaining step obtaining the N number of images;

a low-pass processing step performing low-pass processing on at least one image among the N number of images to generate a low-pass image;

a deciding step deciding a weighting amount in the synthetic processing based on the low-pass image; and

an image synthesizing step performing the synthetic processing on the N number of images according to the weighting amount to generate the synthetic image.