Image processing apparatus for synthesizing images based on a plurality of exposure time periods and image processing method thereof

• US 9,544,505 B2
• Filed: 03/06/2015
• Issued: 01/10/2017
• Est. Priority Date: 04/11/2014
• Status: Active Grant

• Current Assignee: Hanwha Vision Company Limited
• Original Assignee: Hanwha Techwin Co., Ltd. (Hanwha Corporation)
• Inventors: Tsuzuki, Takeru
• Primary Examiner(s): Tran, Nhan T
• Assistant Examiner(s): NGUYEN, CHAN T H
• Application Number:
  US14/640,191
• Publication Number:
  US 20150296116A1
• Time in Patent Office: 676 Days
• Field of Search: 348/222.1
• US Class Current: 1/1
• 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 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors

Abstract

An image processing apparatus includes: a use-image selector configured to generate use-image selection information for selecting one image, from a plurality of images of a subject which are captured for a plurality of exposure time periods, to be used for each region of a synthesized image; an average processor configured to acquire averaged use-image selection information by averaging previous use-image selection information and current use-image selection information; and a synthesizer configured to generate the synthesized image by synthesizing at least two images, among the plurality of images, to constitute the each region according to the averaged use-image selection information.

Claims

1. An image processing apparatus comprising:

a use-image selector configured to generate use-image selection information for selecting one image, from a plurality of images of a subject which are captured for a plurality of exposure time periods, to be used for each region of a synthesized image;

an average processor configured to acquire averaged use-image selection information by averaging previous use-image selection information and current use-image selection information; and

a synthesizer configured to generate the synthesized image by synthesizing at least two images, among the plurality of images, to constitute the each region according to the averaged use-image selection information.

2. The image processing apparatus of claim 1, further comprising:

a motion detector configured to detect motion information about the subject; and

an update processor configured to update the averaged use-image selection information according to the motion detection information,

wherein the synthesizer is configured to generate the synthesized image by synthesizing the at least two images according to the updated use-image selection information.

3. The image processing apparatus of claim 2, wherein the motion detector is configured to detect the motion information using the at least two images.

4. The image processing apparatus of claim 2, wherein the motion detector is configured to detect the motion information using only one image selected from the at least two images.

5. The image processing apparatus of claim 2, further comprising a reduction processor configured to obtain reduced images by respectively reducing the plurality of images,

wherein the use-image selector is configured to generate the use-image selection information according to the reduced images.

6. The image processing apparatus of claim 5, wherein the reduction processor is configured to reduce the plurality of images by dividing each of the plurality of images into plurality of predetermined-size blocks, and averaging pixel values of each of the blocks.

7. The image processing apparatus of claim 5, wherein the motion detector is configured to detect the motion information from the reduced images.

8. The image processing apparatus of claim 2, wherein the update processor is configured to update the averaged use-image selection information so that an image, which is captured for the shortest exposure time period among the plurality of images, is used in a motion region, corresponding to the motion information, of the synthesized image.

9. The image processing apparatus of claim 1, wherein the previous use-image selection information comprises a mixture ratio of at least two previous images for each region in a previously generated synthesized image, and

wherein the current use-image selection information comprises a mixture ratio of the at least two images for the each region in the synthesized image.

10. The image processing apparatus of claim 9, further comprising:

a motion detector configured to detect motion information about the subject; and

an update processor configured to update the averaged use-image selection information according to the motion detection information,

wherein the synthesizer is configured to generate the synthesized image by synthesizing the at least two images according to the updated use-image selection information.

11. An image processing method comprising:

generating use-image selection information for selecting one image, from a plurality of images of a subject which are captured for a plurality of exposure time periods, to be used for each region of a synthesized image;

acquiring averaged use-image selection information by averaging previous use-image selection information and current use-image selection information; and

generating a synthesized image by synthesizing at least two images, among the plurality of images, to constitute the each region according to the averaged use-image selection information.

12. The image processing method of claim 11, further comprising:

detecting motion information about the subject; and

updating the averaged use-image selection information according to the motion detection information,

wherein the synthesized image is generated by synthesizing the at least two images according to the updated use-image selection information.

13. The image processing method of claim 12, wherein the motion information is detected using the at least two images.

14. The image processing method of claim 12, wherein the motion information is detected from only one image selected from the at least two images.

15. The image processing method of claim 12, further comprising obtaining reduced images by respectively reducing the plurality of images,

wherein the use-image selection information is generated according to the reduced images.

16. The image processing method of claim 15, wherein the reducing the plurality of images is performed by dividing each of the plurality of images into plurality of predetermined-size blocks and averaging pixel values of each of the blocks.

17. The image processing method of claim 15, wherein the motion information is detected from the reduced images.

18. The image processing method of claim 12, wherein the averaged use-image selection information is updated so that an image, which is captured for the shortest exposure time period among the plurality of images, is used in a motion region, corresponding to the motion information, of the synthesized image.

19. The image processing method of claim 11, wherein the previous use-image selection information comprises a mixture ratio of at least two previous images for each region in a previously generated synthesized image, and

wherein the current use-image selection information comprises a mixture ratio of the at least two images for the each region in the synthesized image.

20. The image processing method of claim 19, further comprising:

detecting motion information about the subject; and

updating the averaged use-image selection information according to the motion detection information,

wherein the synthesized image is generated by synthesizing the at least two images according to the updated use-image selection information.