Image processing method and apparatus for reducing noise in an image
View Patent ↗An image processing method and apparatus may effectively reduce noise in an image which represents an object photographed by a photographing apparatus. The method may include extracting a first low-frequency component and a first high-frequency component from first image data, and applying a noise reduction filter to the first low-frequency component and to the first high-frequency component to obtain a second low-frequency component and a second high-frequency component, respectively. The method may also include obtaining edge data from the second low-frequency component, and amplifying a portion of the second high-frequency component that corresponds to the edge data to obtain a third high-frequency component. The method may further include combining the second low-frequency component with the third high-frequency component to obtain second image data, and controlling the second image data representing the photographed object to be output to at least one of a storage medium and a display unit.
1. An image processing method comprising:
extracting a first low-frequency component and a first high-frequency component from first image data;
applying a noise reduction filter to the first low-frequency component and to the first high-frequency component to obtain a second low-frequency component and a second high-frequency component, respectively;
obtaining edge data from the second low-frequency component;
amplifying a portion of the second high-frequency component that corresponds to the edge data to obtain a third high-frequency component; and
combining the second low-frequency component with the third high-frequency component to obtain second image data.
2. The method of claim 1 , wherein extracting the first low-frequency component and the first high-frequency component comprises using at least one of a low-pass filter and a high-pass filter.
3. The method of claim 1 , wherein applying the noise reduction comprises applying a bilateral filter to the first low-frequency component and to the first high-frequency component.
4. The method of claim 1 , wherein amplifying a portion of the second high-frequency component comprises amplifying substantially only the portion of the second high-frequency component that corresponds to the edge data to obtain the third high-frequency component.
5. The method of claim 1 , wherein extracting the first low-frequency component and the first high-frequency component comprises:
extracting one of the first low-frequency component and the first high-frequency component from the first image data; and
extracting the other of the first low-frequency component and the first high-frequency component based on a difference between the first image data and the extracted one of the first low-frequency component and the first high-frequency component.
6. The method of claim 1 , further comprising photographing the object using the photographing apparatus.
7. The method of claim 1 , further comprising extracting the first image data from at least one of a storage medium and an image capture device.
8. The method of claim 1 , further comprising outputting the second image data to at least one of a storage medium and a display unit.
9. An image processing apparatus comprising:
a low-frequency component extraction unit configured to extract a first low-frequency component from first image data;
a high-frequency component extraction unit configured to extract a first high-frequency component from the first image data;
a noise reduction unit configured to apply a noise reduction filter to the first low-frequency component and the first high-frequency component to obtain a second low-frequency component and a second high-frequency component, respectively;
an edge data obtaining unit configured to obtain edge data from the second low-frequency component;
a high-frequency component tuning unit configured to amplify a portion of the second high-frequency component that corresponds to the edge data to obtain a third high-frequency component; and
an image synthesis unit configured to combine the second low-frequency component with the third high-frequency component to obtain second image data.
10. The apparatus of claim 9 , wherein the low-frequency component extraction unit comprises a low-pass filter.
11. The apparatus of claim 9 , wherein the high-frequency component extraction unit comprises a high-pass filter.
12. The apparatus of claim 9 , wherein the noise reduction unit comprises a bilateral filter.
13. The apparatus of claim 9 , wherein the high-frequency component tuning unit is further configured to amplify substantially only the portion of the second high-frequency component that corresponds to the edge data to obtain the third high-frequency component.
14. The apparatus of claim 9 , wherein the high-frequency component extraction unit is further configured to extract the first high-frequency component based on a difference between the first image data and the first low-frequency component.
15. The apparatus of claim 9 , further comprising an image data input/output unit configured to input the first image data from at least one of an image capture device and a storage medium and output the second image data to at least one of a display unit and a storage medium.
16. A computer-readable storage medium having stored thereon a program, the program being executable by a processor to perform an image processing method, the method comprising:
extracting a first low-frequency component and a first high-frequency component from first image data, the first image data representing an object photographed by a photographing apparatus;
applying a noise reduction filter to the first low-frequency component and to the first high-frequency component to obtain a second low-frequency component and a second high-frequency component, respectively;
obtaining edge data from the second low-frequency component;
amplifying a portion of the second high-frequency component that corresponds to the edge data to obtain a third high-frequency component;
combining the second low-frequency component with the third high-frequency component to obtain second image data; and
controlling the second image data representing the object photographed by a photographing apparatus to be output to at least one of a storage medium and a display unit.
17. The storage medium of claim 16 , wherein extracting the first low-frequency component and the first high-frequency component comprises using at least one of a low-pass filter and a high-pass filter.
18. The storage medium of claim 16 , wherein applying the noise reduction filter to obtain the second low-frequency component and the second high-frequency component comprises using a bilateral filter.
19. The storage medium of claim 16 , wherein amplifying a portion of the second high-frequency component comprises amplifying substantially only the portion of the second high-frequency component that corresponds to the edge data to obtain the third high-frequency component.
20. The storage medium of claim 16 , wherein extracting the first low-frequency component and the first high-frequency component comprises:
extracting one of the first low-frequency component and the first high-frequency component from the first image data; and
extracting the other of the first low-frequency component and the first high-frequency component based on a difference between the first image data and the extracted one of the first low-frequency component and the first high-frequency component.