METHOD AND APPARATUS FOR INCREASING DYNAMIC RANGE OF IMAGE BY USING ELECTRONIC SHUTTER

• US 20110050946A1
• Filed: 08/31/2010
• Published: 03/03/2011
• Est. Priority Date: 08/31/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Tae-ho, Usui, Takafumi
• Granted Patent: US 8,587,692 B2
• Time in Patent Office: Days
• US Class Current: 348/222.1
• CPC Class Codes: G03B 9/40 Double plate
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 25/531 by controlling rolling shutters in CMOS SSIS
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors

Abstract

A method for increasing a dynamic range of an image by using an electronic shutter of a camera, the method including initiating exposure of an image sensor by moving a mechanical front curtain included in the camera; moving an electronic front curtain with respect to at least one pixel of the image sensor according to a control pulse signal of the electronic shutter; and blocking the exposure of the image sensor by moving a mechanical rear curtain included in the camera.

Claims

1. A method for increasing a dynamic range of an image by using an electronic shutter of a camera, the method comprising:

initiating exposure of an image sensor by moving a mechanical front curtain included in the camera;

moving an electronic front curtain with respect to at least one pixel of the image sensor according to a control pulse signal of the electronic shutter; and

blocking the exposure of the image sensor by moving a mechanical rear curtain included in the camera.

2. The method of claim 1, wherein the electronic front curtain is moved nonlinearly in accordance with speed and travel characteristics of the mechanical front curtain and the mechanical rear curtain.

3. The method of claim 2, further comprising setting a line-based or pixel-based exposure initiating time of the image sensor to be different from an exposure initiating time due to the mechanical front curtain.

4. The method of claim 3, wherein setting the line-based or pixel-based exposure initiating time of the image sensor comprises applying the control pulse signal to odd or even lines of the image sensor, or applying the control pulse signal to odd or even pixels of the image sensor, respectively.

5. The method of claim 4, wherein the control pulse signal of the electronic shutter is generated as a scan pattern of the electronic shutter based on parameters that are external factors including at least one of a position, a temperature, and a humidity of the camera.

6. The method of claim 1, further comprising, after blocking the exposure of the image sensor by moving the mechanical rear curtain, acquiring a long exposure image by using the mechanical front curtain and acquiring a short exposure image by using the electronic front curtain.

7. The method of claim 6, further comprising generating a High Dynamic Range (HDR) image with an increased dynamic range by synthesizing the acquired long exposure image and the acquired short exposure image.

8. The method of claim 1, further comprising moving the electronic front curtain at least one time with respect to at least one pixel of the image sensor according to the control pulse signal of the electronic shutter.

9. The method of claim 8, further comprising, after blocking the exposure of the image sensor by moving the mechanical rear curtain, acquiring a long exposure image by using the mechanical front curtain and acquiring a short exposure image by using the electronic front curtain.

10. The method of claim 1, wherein initiating the exposure of the image sensor included in the camera is performed by using the electronic shutter of the camera.

11. An apparatus for increasing a dynamic range of an image by using an electronic shutter of a camera, the apparatus comprising:

a mechanical front curtain moving unit for initiating exposure of an image sensor by moving a mechanical front curtain included in the camera;

an electronic front curtain moving unit for moving an electronic front curtain with respect to at least one pixel of the image sensor according to a control pulse signal of the electronic shutter; and

a mechanical rear curtain moving unit for blocking the exposure of the image sensor by moving a mechanical rear curtain included in the camera.

12. The apparatus of claim 11, wherein the electronic front curtain is moved nonlinearly in accordance with speed and travel characteristics of the mechanical front curtain and the mechanical rear curtain.

13. The apparatus of claim 11, further comprising a multi-exposure pulse signal generating unit for generating the control pulse signal so that a line-based or pixel-based exposure initiating time of the image sensor is set to be different from an exposure initiating time due to the mechanical front curtain.

14. The apparatus of claim 13, wherein the multi-exposure pulse signal generating unit comprises a linear-line control unit for applying the control pulse signal to odd or even lines of the image sensor and a zigzag control unit for applying the control pulse signal to odd or even pixels of the image sensor.

15. The apparatus of claim 11, further comprising a scan pattern generating unit for generating a scan pattern of the electronic shutter based on parameters, which are external factors including at least one of a position, a temperature, and a humidity of the camera, in order to generate the control pulse signal.

16. The apparatus of claim 11, further comprising a multi-exposure image acquiring unit for acquiring, after exposure of the image sensor is blocked by the mechanical rear curtain, a long exposure image by using the mechanical front curtain and a short exposure image by using the electronic front curtain.

17. The apparatus of claim 16, further comprising an image synthesizing unit for generating an HDR image with an increased dynamic range by synthesizing the acquired long exposure image and the acquired short exposure image.

18. The apparatus of claim 11, wherein the electronic front curtain moving unit moves the electronic front curtain at least one time with respect to at least one pixel of the image sensor according to the control pulse signal of the electronic shutter.

19. The apparatus of claim 18, further comprising a multi-exposure image acquiring unit for acquiring, after exposure of the image sensor is blocked by the mechanical rear curtain, a long exposure image by using the mechanical front curtain and a short exposure image by using the electronic front curtain.

20. A computer-readable recording medium having embodied thereon a program for executing a method for increasing a dynamic range of an image by using an electronic shutter of a camera, comprising:

a first code segment for initiating exposure of an image sensor by moving a mechanical front curtain included in the camera;

a second code segment for moving an electronic front curtain with respect to at least one pixel of the image sensor according to a control pulse signal of the electronic shutter; and

a third code segment for blocking the exposure of the image sensor by moving a mechanical rear curtain included in the camera.