Apparatus and method of obtaining image and apparatus and method of processing image

• US 20090185041A1
• Filed: 06/16/2008
• Published: 07/23/2009
• Est. Priority Date: 01/22/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd., Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kang, Dong-goo, Lee, Seong-deok, Oh, Hyun-hwa, Wey, Ho-cheon
• Granted Patent: US 8,169,491 B2
• Time in Patent Office: Days
• US Class Current: 348/208.100
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20201 Motion blur correction
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations

Abstract

Provided are an apparatus and method of obtaining a high-quality image by efficiently processing an image obtained at low-light levels. The image obtaining apparatus comprises a sensor which detects a pixel array value by using a color filter including color pixels for obtaining a color image and a reference pixel for obtaining a reference image used for hand-trembling function estimation; an exposure controller which controls exposure times of the color pixels and the reference pixel; and an image generator which generates a long-exposure color image signal and a short-exposure reference image signal from the detected pixel array value, the long-exposure color image signal and the short-exposure reference image signal being aligned with each other. Accordingly, accurate estimation of the hand-trembling function is possible, thereby enabling the high-quality color image restoration.

Claims

1. An image obtaining apparatus comprising:

a sensor which detects a pixel array value by using a color filter including color pixels for obtaining a color image and a reference pixel for obtaining a reference image used for hand-trembling function estimation;

an exposure controller which controls exposure times of the color pixels and the reference pixel; and

an image generator which generates a long-exposure color image signal and a short-exposure reference image signal from the detected pixel array value, the long-exposure color image signal and the short-exposure reference image signal being aligned with each other.

2. The image obtaining apparatus of claim 1, wherein the exposure controller synchronizes exposure starting times of the color pixels and the reference pixel and controls the exposure time of the color pixels to be longer than the exposure time of the reference pixel.

3. The image obtaining apparatus of claim 2, wherein the exposure controller controls the sensor such that a short-exposure of the reference pixel takes place repeatedly while the color pixels are being exposed in order to obtain initial information of the hand-trembling function.

4. The image obtaining apparatus of claim 1, wherein the image generator performs interpolation on the pixel array value detected through the color pixels and the reference pixel so as to generate long-exposure image signals of respective colors of the color pixels and a short-exposure image signal.

5. A method of obtaining an image, the method comprising:

obtaining a pixel array value by controlling exposure times of color pixels for obtaining a color image and a reference pixel for obtaining a reference image used for hand-trembling function estimation, the color pixels and the reference pixel being included in a color filter; and

generating a long-exposure color image signal and a short-exposure reference image signal by using the obtained pixel array value, the long-exposure color image signal and the short-exposure reference image signal being aligned with each other.

6. The method of claim 5, wherein in the controlling of the exposure times, exposure starting times of the color pixels and the reference pixel are synchronized with each other, and the exposure time of the color pixels is set to be longer than the exposure time of the reference pixel.

7. The method of claim 6, wherein in the controlling of the exposure times, the exposure time of the reference pixel is controlled such that a short-exposure of the reference pixel takes place repeatedly while the color pixels are being exposed in order to obtain initial information of the hand-trembling function.

8. The method of claim 5,.wherein in the generating of the image signals, interpolation is performed on the pixel array value detected through the color pixels and the reference pixel so as to generate long-exposure image signals of respective colors of the color pixels and a short-exposure image signal.

9. An image processing apparatus comprising:

an image obtaining unit which obtains a long-exposure color image signal and a short-exposure reference image signal, which are aligned with each other, by controlling an exposure time of a color filter including color pixels for obtaining a color image and a reference pixel for obtaining a reference image used for hand-trembling function estimation;

a function estimating unit which estimates a hand-trembling function by using the long-exposure color image signal and the short-exposure reference image signal; and

an image restoring unit which generates a restored image signal by performing deconvolution on the long-exposure color image signal by the use of the estimated hand-trembling function.

10. The image processing apparatus of claim 9, wherein the image obtaining unit obtains the long-exposure color image signal and the short-exposure reference image signal by synchronizing exposure starting times of the color pixels and the reference pixel and controlling the exposure time of the color pixels to be longer than the exposure time of the reference pixel.

11. The image processing apparatus of claim 10, wherein the image obtaining unit collects a plurality of short-exposure reference image signals by controlling short-exposure of the reference pixel to take place repeatedly while the color pixels are being exposed, and the function estimating unit obtains information by tracing the locus of hand-trembling by the use of the collected reference image signals and uses the information as initial information of the hand-trembling function.

12. The image processing apparatus of claim 9, wherein the function estimating unit reduces noise of the long-exposure color image signal and the short-exposure reference image signal, converts the noise-reduced long-exposure color image signal into a long-exposure single-channel image signal, and estimates the hand-trembling function by using the converted long-exposure single-channel image signal and the noise-reduced short-exposure reference image signal.

13. A method of processing image, the method comprising:

obtaining a long-exposure color image signal and a short-exposure reference image signal, which are aligned with each other, by controlling an exposure time of a color filter including color pixels for obtaining a color image and a reference pixel for obtaining a reference image used for hand-trembling function estimation;

estimating a hand-trembling function by using the long-exposure color image signal and the short-exposure reference image signal; and

generating a restored image signal by performing deconvolution on the long-exposure color image signal by using the estimated hand-trembling function.

14. The method of claim 13, wherein the obtaining of the image signals, exposure starting times of the color pixels and the reference pixel are synchronized with each other, and the exposure time of the color pixels is set to be longer than the exposure time of the reference pixel.

15. The method of claim 14, wherein in the obtaining of the image signals, plurality of short-exposure reference image signals are collected by controlling short-exposure of the reference pixel to take place repeatedly while the color pixels are being exposed, and in the estimating of the hand-trembling function, information is obtained by tracing the locus of hand-trembling by the use of the collected reference image signals and the obtained information is used as initial information of the hand-trembling function.

16. The method of claim 13, wherein the estimating of the hand-trembling function comprises:

reducing noise of the long-exposure color image signal and the short-exposure image signal;

converting the noise-reduced long-exposure color image signal into a long-exposure single-channel image signal; and

estimating the hand-trembling function by using the converted long-exposure single-channel image signal and the noise-reduced short-exposure reference image signal.