METHOD AND APPARATUS FOR IMPROVING DYNAMIC RANGE OF IMAGE

• US 20090002525A1
• Filed: 11/16/2007
• Published: 01/01/2009
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Sang-jin, UM, Kyu-hoi, IM, Na-ri
• Granted Patent: US 8,456,555 B2
• Time in Patent Office: Days
• US Class Current: 348/241
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions

Abstract

Provided are a method and apparatus for improving a dynamic range of an image. The method of improving a dynamic range of an image, which is obtained by a sensor unit of an image capture device, includes: creating an input image by using the sensor unit which has a plurality of lines and has different integration times for the individual lines; and creating an interpolated image by performing interpolation filtering on the input image by using neighboring lines of a current line which have different integration times.

Claims

1. A method of improving a dynamic range of an image which is obtained by a sensor unit of an image capture device, the method comprising:

creating an input image using the sensor unit which has a plurality of lines and has different integration times for individual lines; and

creating an interpolated image by performing interpolation filtering on the input image by using neighboring lines of a current line which have different integration times.

2. The method of claim 1, wherein in the creating the input image, the integration times of the sensor unit are previously determined for the individual lines.

3. The method of claim 1, wherein the creating the input image comprises:

obtaining an initial image using the sensor unit;

setting the different integration times for the individual lines of the sensor unit by using characteristics of the initial image; and

creating the input image using the sensor unit which has the different integration times set for the individual lines.

4. The method of claim 1, wherein the creating the interpolated image comprises:

calculating a correlation between the current line and the neighboring lines; and

controlling filter coefficients of the interpolation filtering based on the correlation.

5. The method of claim 4, wherein the interpolation filtering is used to calculate weighted summation which is obtained by multiplying a pixel value of a pixel in the current line by a certain weight and multiplying at least one of pixel value of pixels in each of the neighboring lines by another weight and adding the multiplied pixel values together.

6. The method of claim 3, wherein in the setting the integration times, the integration times for at least one of the lines are individually controlled based on a dynamic range of the initial image.

7. The method of claim 3, wherein in the setting the integration times, the integration times for at least one of the lines are individually controlled based on a noise level of the initial image.

8. The method of claim 3, wherein in the setting the integration times, the integration times for at least one of the lines are individually controlled based on an amount of movement blurring that occurs if there is movement in the initial image.

9. The method of claim 4, wherein the filter coefficients are determined based on the integration times for the lines.

10. The method of claim 4, wherein the filter coefficients are determined based on a dynamic range of the input image.

11. An apparatus for improving an image dynamic range of an image capture device, the apparatus comprising:

an input image creating unit which creates an input image by converting light into electronic signals, the light being incident to individual lines for a period of an integration time which is different for each of the lines; and

an image processing unit which performs interpolation filtering on the input image, by using a current line and neighboring lines which have different integration times, and creates an interpolated image.

12. The apparatus of claim 11, wherein the input image creating unit comprises a sensor unit which converts the light, which is incident to the individual lines for the period of the integration time which is different for each line, into the electronic signals.

13. The apparatus of claim 11, wherein the input image creating unit comprises:

a sensor unit which obtains an image by converting the incident light into the electronic signals; and

an integration time controlling unit which individually controls the integration times for the lines of the sensor unit using characteristics of an initial image obtained by the sensor unit.

14. The apparatus of claim 11, wherein the input image creating unit comprises a sensor unit which obtains an image by converting the incident light into the electronic signals and an integration time controlling unit which individually controls the integration times for lines of the sensor unit, and the image processing unit transmits the individually controlled integration times for the lines of the sensor unit by using characteristics of an initial image created by the input image creating unit.

15. The apparatus of claim 11, wherein the image processing unit comprises:

a correlation calculation unit which calculates correlation between the current line and the neighboring lines;

an interpolation filter creating unit which controls interpolation filter coefficients of the interpolation filtering based on the correlation; and

an interpolation filtering unit which performs the interpolation filtering using the interpolation filter.

16. The apparatus of claim 15, wherein the interpolation filtering is used to calculate weighted summation which is obtained by multiplying a pixel value of a pixel in the current line and at least one of pixel value of pixels in each of the neighboring lines by a certain weight and adding the multiplied pixel together.

17. The apparatus of claim 13, wherein the integration time controlling unit controls and sets at least one of the integration times for the lines differently based on a dynamic range of the initial image.

18. The apparatus of claim 13, wherein the integration time controlling unit controls and sets at least one of the integration times for the lines differently based on a noise level of the initial image.

19. The apparatus of claim 13, wherein the integration time controlling unit controls and sets the integration times for at least one line differently based on an amount of movement blurring that occurs when there is movement in the initial image.

20. The apparatus of claim 14, wherein the image processing unit controls and sets the integration times for at least one of the lines differently based on a dynamic range of the initial image.

21. The apparatus of claim 14, wherein the image processing unit controls and sets the integration times for at least one of the lines differently based on a noise level of the initial image.

22. The apparatus of claim 14, wherein the image processing unit controls and sets the integration times of at least one of the lines differently based on an amount of movement blurring that occurs if there is movement in the initial image.

23. The apparatus of claim 15, wherein the interpolation filter creating unit determines the interpolation filter coefficients based on the integration times for lines.

24. The apparatus of claim 15, wherein the interpolation filter creating unit determines the interpolation filter coefficients based on a dynamic range of the input image.

25. A computer readable recording medium having embodied thereon a computer program for executing a method of improving a dynamic range of an image which is obtained by a sensor unit of an image capture device, the method comprising:

creating an input image using the sensor unit which has a plurality of lines and has different integration times for individual lines; and

creating an interpolated image by performing interpolation filtering on the input image by using neighboring lines of a current line which have different integration times.