Image processing apparatus, image taking apparatus and program

• US 20040239779A1
• Filed: 05/24/2004
• Published: 12/02/2004
• Est. Priority Date: 05/29/2003
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Washisu, Koichi
• Granted Patent: US 7,756,354 B2
• Time in Patent Office: Days
• US Class Current: 348/239
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors

Abstract

An image processing apparatus, which obtains a synthesized image whose exposure is corrected by synthesizing a first image and a second image, is disclosed. The image processing apparatus comprises a detection section which detects an amount of displacement of the second image with respect to the first image which is a reference image, a coordinate conversion section which performs coordinate conversion to the second image so as to conform to the first image, and a synthesis section which synthesizes the second image having been subjected to the coordinate conversion with the first image.

Claims

1. An image processing apparatus which obtains a synthesized image whose exposure is corrected by synthesizing a first image and a second image which are taken by using an image pickup device sequentially, comprising:

a detection section which detects an amount of displacement of the second image with respect to the first image which is a reference image;

a coordinate conversion section which performs coordinate conversion to the second image so as to conform to the first image on the basis of the detection result of the detection section;

a synthesis section which synthesizes the second image having been subjected to the coordinate conversion with the first image; and

a controller which sets an image taken by using light from an electric flash to the first image.

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

the detection section detects the amount of displacement on the basis of a at least one specific point in a at least one region whose brightness difference with respect to the second image is lower than a predetermined value in the first image.

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

an adjusting section which adjusts brightness in a first region in the second image corresponding to an illuminated region irradiated with the light in the first image.

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

the adjusting section darkens the brightness in the first region.

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

the adjusting section adjusts brightness so as to shade-off a boundary between the first region and a second region which is a region other than the first region in the second image.

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

the adjusting section changes brightness of the boundary in stages or continuously.

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

a synthesis prohibiting section which prohibits an image synthesis operation of the synthesis section when the brightness difference at a specific region in the first image with respect to the second image is greater than a predetermined value.

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

an adjustment prohibiting section which prohibits an adjustment operation of the adjusting section when the brightness difference at a specific region in the first image with respect to the second image is smaller than a predetermined value.

9. An image taking apparatus comprising:

the image processing apparatus according to claim 1;

and

an image pickup device.

10. The image taking apparatus according to claim 9, wherein the light is used when a last image among a plurality of images is taken.

11. The image taking apparatus according to claim 9, further comprising

a recording section, in which stores the first image and the synthesized image are recorded.

12. A program for obtaining a synthesized image whose exposure is corrected by synthesizing a first image and a second image which are taken sequentially by using an image pickup device, comprising:

a detecting step of detecting an amount of displacement of the second image with respect to the first image which is a reference image;

a coordinate conversion step of performing coordinate conversion to the second image so as to conform to the first image on the basis of the detection result in the detecting step; and

a synthesizing step of synthesizing the second image having been subjected to the coordinate conversion with the first image; and

a setting step of setting an image taken by using light from an electric flash to the first image.

13. The program according to claim 12, wherein

in the detecting step, the amount of displacement is detected on the basis of a at least one specific point in a at least one region whose brightness difference with respect to the second image is lower than a predetermined value in the first image.

14. The program according to claim 12, further comprising:

an adjusting step of adjusting brightness in a first region in the second image corresponding to an illuminated region irradiated with the light in the first image.

15. The program according to claim 14, wherein

in the adjusting step, the brightness in the first region is darkened.

16. The program according to claim 14, wherein

in the adjusting step, the brightness is adjusted so as to shade-off a boundary between the first region and a second region which is a region other than the first region in the second image.

17. The program according to claim 16, wherein

in the adjusting step, the brightness of the boundary is changed in stages or continuously.

18. The program according to claim 12, wherein

in the synthesizing step, an image synthesis operation is prohibited when the brightness difference at a specific region in the first image with respect to the second image is greater than a predetermined value.

19. The program according to claim 14, wherein

in the adjusting step, a brightness adjustment operation is prohibited when the brightness difference at a specific region in the first image with respect to the second image is smaller than a predetermined value.