Digital photographing apparatus, method of controlling the digital photographing apparatus, and recording medium having recorded thereon a program for executing the method

• US 20090207258A1
• Filed: 02/04/2009
• Published: 08/20/2009
• Est. Priority Date: 02/18/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Techwin Corporation (Hanwha Corporation)
• Inventors: Jang, Soon-geun, Gwak, Jin-pyo, Ahn, Eun-sun
• Granted Patent: US 8,350,955 B2
• Time in Patent Office: Days
• US Class Current: 348/208.100
• 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 23/743 Bracketing, i.e. taking a series of images with varying exposure conditions
• CPC Class Codes: H04N 23/76 by influencing the image signals

Abstract

Provided are a digital photographing apparatus by which a clear image may be obtained despite shaking of the digital photographing apparatus during a photographing operation, a method of controlling the digital photographing apparatus, and a recording medium having recorded thereon a program for executing the method. The digital photographing apparatus includes a data obtaining unit for obtaining first data of a first image captured using a long time exposure and obtaining second data of a second image captured using a short time exposure; a motion vector extraction unit for extracting a motion vector between a position of a subject in the first image and the position of the subject in the second image; a blurring determination unit for determining whether blurring exists in the first image; a subject location determination unit for determining whether the position of the subject in the first image is identical to the position of the subject in the second image; and a data combination unit for creating data having luminance data of the second data and having composite color data obtained by combining color data of the first and second data, as ultimate data.

Claims

1. A digital photographing apparatus comprising:

a data obtaining unit for obtaining first data of a first image captured using a long time exposure and obtaining second data of a second image captured using a short time exposure;

a motion vector extraction unit for extracting a motion vector between a position of a subject in the first image and the position of the subject in the second image;

a blurring determination unit for determining whether blurring exists in the first image;

a subject location determination unit for determining whether the position of the subject in the first image is identical to the position of the subject in the second image; and

a data combination unit for creating data having luminance data of the second data and having composite color data obtained by combining color data of the first and second data, as ultimate data.

2. The digital photographing apparatus of claim 1, wherein the second data is regarded as the ultimate data if the motion vector extraction unit fails to extract the motion vector,

wherein the blurring determination unit determines whether blurring exists in the first image if the motion vector extraction unit successfully extracts the motion vector,

wherein the second data is regarded as the ultimate data if the blurring determination unit determines that blurring exists in the first image, wherein the subject location determination unit determines whether the position of the subject in the first image is identical to the position of the subject in the second image if the blurring determination unit determines that blurring does not exist in the first image,

wherein the first data is regarded as the ultimate data if the subject location determination unit determines that the position of the subject in the first image is identical to the position of the subject in the second image, and

wherein the data combination unit creates the data having the luminance data of the second data and having the composite color data obtained by combining the color data of the first and second data, as the ultimate data, if the subject location determination unit determines that the position of the subject in the first image is not identical to the position of the subject in the second image.

3. The digital photographing apparatus of claim 1, wherein the motion vector extraction unit extracts the motion vector between the position of the subject in the first image and the position of the subject in the second image, by using the luminance data of the first and second data obtained by the data obtaining unit.

4. The digital photographing apparatus of claim 1, wherein, assuming that I₁(x,y) indicates the luminance data of an (x,y) pixel of the first image, I₂(x,y) indicates the luminance data of an (x,y) pixel of the second image, (dx₁, dy₁) indicates an amount of movement of one of matched first and second images in one direction so as not to be matched to each other, and (dx₂, dy₂) indicates an amount of movement of one of the matched first and second images in another direction so as not to be matched to each other, the blurring determination unit matches the first and second images to each other, calculates R(0), R(−

1), and R(1) by respectively using Equations 1, 2, and 3, in a region A where the first and second images overlap each other, calculates C by using Equation 4, and determines that blurring exists in the first image if C is smaller than a preset value.

5. The digital photographing apparatus of claim 4, wherein, assuming that Area indicates an area of the region where the first and second images overlap each other and κ

indicates a tuning parameter, the preset value is calculated by using Equation 5.

κ

×

Area (5)

6. The digital photographing apparatus of claim 5, wherein κ

has a value 14.

7. The digital photographing apparatus of claim 1, wherein, assuming that I₁(x,y) indicates the luminance data of an (x,y) pixel of the first image, I₂(x,y) indicates the luminance data of an (x,y) pixel of the second image, Area indicates an area of the region where the first and second images overlap each other, σ

² indicates a noise distribution of the first image, and κ

indicates a tuning parameter, the blurring determination unit matches the first and second images to each other, calculates R(0) by using Equation 1 in a region A where the first and second images overlap each other, and determines that blurring exists in the first image if R(0) is larger than a value calculated by using Equation 6.

8. The digital photographing apparatus of claim 1, wherein the subject location determination unit determines that the position of the subject in the first image is identical to the position of the subject in the second image if the motion vector between the position of the subject in the first image and the position of the subject in the second image is smaller than a preset size.

9. The digital photographing apparatus of claim 1, wherein the subject location determination unit determines that the position of the subject in the first image is identical to the position of the subject in the second image if a difference between the position of the subject in the first image and the position of the subject in the second image is equal to or smaller than two pixels, both in horizontal and vertical directions.

10. A method of controlling a digital photographing apparatus, the method comprising:

(a) obtaining first data of a first image captured using a long time exposure and obtaining second data of a second image captured using a short time exposure;

(b) determining whether a motion vector exists between a position of a subject in the first image and the position of the subject in the second image;

(c) regarding the second data as ultimate data if it is determined that the motion vector does not exist in (b);

(d) determining whether blurring exists on the first image if it is determined that the motion vector exists in (b);

(e) regarding the second data as the ultimate data if it is determined that blurring exists in the first image in (d);

(f) determining whether the position of the subject in the first image is identical to the position of the subject in the second image if it is determined that blurring does not exist in the first image in (d);

(g) regarding the first data as the ultimate data if the positions are determined to be identical in (f); and

(h) regarding data having luminance data of the second data and having composite color data obtained by combining color data of the first and second data, as the ultimate data, if the positions are determined not to be identical in (f).

11. The method of claim 10, wherein (b) comprises determining that the motion vector exists if the position of the subject in the first image is identical to the position of the subject in the second image and thus the motion vector has a value 0.

12. The method of claim 10, wherein (b) comprises determining whether the motion vector exists between the position of the subject in the first image and the position of the subject in the second image, by using the luminance data of the first and second data.

13. The method of claim 10, wherein, assuming that I₁(x,y) indicates the luminance data of an (x,y) pixel of the first image, I₂(x,y) indicates the luminance data of an (x,y) pixel of the second image, (dx₁, dy₁) indicates an amount of movement of one of matched first and second images in one direction so as not to be matched to each other, and (dx₂, dy₂) indicates an amount of movement of one of the matched first and second images in another direction so as not to be matched to each other, (d) comprises:

matching the first and second images to each other;

calculating R(0), R(−

1), and R(1) by respectively using Equations 1, 2, and 3, in a region A where the first and second images overlap each other;

calculating C by using Equation 4; and

determining that blurring exists in the first image if C is smaller than a preset value.

14. The method of claim 13, wherein, assuming that Area indicates an area of the region where the first and second images overlap each other and κ

indicates a tuning parameter, the preset value is calculated by using Equation 5.

κ

×

Area  

 

(5)

15. The method of claim 14, wherein κ

has a value 14.

16. The method of claim 10, wherein, assuming that I₁(x,y) indicates the luminance data of an (x,y) pixel of the first image, I₂(x,y) indicates the luminance data of an (x,y) pixel of the second image, Area indicates an area of the region where the first and second images overlap each other, a σ

² indicates a noise distribution of the first image, and κ

indicates a tuning parameter, (d) comprises;

matching the first and second images to each other;

calculating R(0) by using Equation 1 in a region A where the first and second images overlap each other; and

determining that blurring exists in the first image if R(0) is larger than a value calculated by using Equation 6.

17. The method of claim 10, wherein (f) comprises determining that the position of the subject in the first image is identical to the position of the subject in the second image if the motion vector between the position of the subject in the first image and the position of the subject in the second image is smaller than a preset size.

18. The method of claim 10, wherein (f) comprises determining that the position of the subject in the first image is identical to the position of the subject in the second image if a difference between the position of the subject in the first image and the position of the subject in the second image is equal to or smaller than two pixels both in horizontal and vertical directions.

19. A recording medium having recorded thereon a program for executing the method of claim 10.