Method for high dynamic range imaging

• US 20100194902A1
• Filed: 05/11/2009
• Published: 08/05/2010
• Est. Priority Date: 02/05/2009
• Status: Active Grant

• Current Assignee: National Chung Cheng University
• Original Assignee: National Chung Cheng University
• Inventors: Chang, Wei-Zhe, Lin, Huei-Yung
• Granted Patent: US 8,208,048 B2
• Time in Patent Office: Days
• US Class Current: 348/222.1
• 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

A method for high dynamic range imaging includes the steps of arranging at least two cameras parallel and meanwhile capturing a plurality of images of one scene with different exposures by the at least two cameras; adjusting the captured images for the same exposure thereof subject to the response functions of the cameras respectively and then defining a plurality of characteristic spots in each of the images; combining the characteristic spots corresponding to the images respectively to get a displacement of the corresponding characteristic spot in each image and to further get a disparity map; and applying the displacement between the two corresponding characteristic spots in the corresponding images and synthesizing the images to form a synthetic image.

Claims

1. A method for high dynamic range imaging, comprising steps of:

a) operating at least two cameras to capture images of a scene with different exposures, wherein each of the at least two cameras has its corresponding camera response function;

b) adjusting the captured images for the same exposure subject to the response function of the corresponding camera and defining a plurality of characteristic spots in each of the images;

c) combining the characteristic spots corresponding to the images to get a disparity map of the characteristic spots and to further get a disparity map; and

d) applying the disparity map and combing the images to form a synthetic image.

2. The method as defined in claim 1, wherein the images with different exposures in the step a) are captured according to different exposure time.

3. The method as defined in claim 1, wherein the images with different exposures in the step a) are captured according to different aperture sizes.

4. The method as defined in claim 1, wherein the step b) further comprises a sub-step of computing depth information of the images based on the corresponding response functions respectively.

5. The method as defined in claim 1, wherein the step d) further comprises a sub-step of correcting an afterimage incurred by synthesis of incorrect characteristic spots.

6. The method as defined in claim 1, wherein the at least two cameras in the step a) are arranged at the same elevation.

7. The method as defined in claim 1, wherein the at least two cameras in the step a) are arranged in parallel.