Apparatus and method for adjusting hue

1. A method of adjusting hue, the method comprising:

(a) setting a rotation angle of hue of each of regions of an image divided into a predetermined number using angle areas about a central point;

(b) calculating coordinates of hue values Cr and Cb of an input pixel to determine in which of the regions the pixel is located;

(c) calculating an angle of the pixel in the determined region;

(d) calculating a movement angle using a rotation angle set for the determined region and a rotation angle set for an adjacent region, and determining whether interpolation is to be performed to the angle of the pixel based on a difference between the movement angle and the angle of the pixel; and

(e) if it is determined that the interpolation is to be performed, calculating an interpolation angle based on the movement angle and the angle of the pixel, and moving the pixel by the interpolation angle,

wherein, in operation (d), it is determined that the interpolation is to be performed if the movement angle is equal to or greater than the angle of the pixel, and it is determined that the interpolation is not to be performed if the movement angle is less than the angle of the pixel.

2. The method of claim 1 , wherein operation (b) comprises:

(b-1) calculating the coordinates of the hue values Cr and Cb of the pixel;

(b-2) rotating the coordinates by 45°; and

(b-3) determining the region by determining hue polarities of the coordinates and the coordinates rotated by 45°.

3. The method of claim 1 , wherein operation (c) comprises calculating the angle of the pixel by normalizing a ratio between the hue values Cr and Cb.

4. The method of claim 1 , wherein, in operation (c), the angle of the pixel is calculated by an equation of

θ

≅

sin

⁢

⁢

θ

≅

tan

⁢

⁢

θ

=

Cr

Cb

.

5. The method of claim 1 , wherein operation (d) comprises searching for the movement angle which is preset as corresponding to an absolute value of a difference between the rotation angle set for the determined region and the rotation angle set for the adjacent region.

6. The method of claim 5 , wherein the movement angle is one of a plurality of movement angles preset respectively for a plurality of values including the absolute value of the different between the rotation angle set for the determined region and the rotation angle set for the adjacent region.

7. The method of claim 1 , further comprising, if it is determined that the interpolation is not to be performed as a result of the determination in operation (d), moving the pixel by the rotation angle set for the determined region.

8. The method of claim 1 , further comprising, in operation (e), calculating an interpolation ratio by using the movement angle and the angle of the pixel and moving the pixel by the interpolation ratio.

9. The method of claim 1 , wherein, in operation (e), the interpolation angle is calculated by an equation as follows:

the interpolation angle=(the rotation angle set for the determined region(128−ratio)+the rotation angle set for the adjacent region×ratio)/128,

where the ration is (the angle of the pixel/the movement angle)×128.

10. An apparatus for adjusting hue, the apparatus comprising:

a determiner which calculates coordinates of hue values Cr and Cb of an input pixel to determine in which of regions of an image divided into a predetermined number the pixel is located, and calculates an angle of the pixel in the determined region;

an interpolator which calculates a movement angle using a rotation angle set for the determined region and a rotation angle set for an adjacent region, determines whether interpolation is to be performed to the angle of the pixel based on a difference between the movement angle and the angle of the pixel, and calculates an interpolation angle based on the movement angle and the angle of the pixel; and

a movement unit which moves the pixel by the interpolation angle,

wherein the interpolator determines that the interpolation is to be performed if the movement angle is equal to or greater than the angle of the pixel, and determines that the interpolation is not to be performed if the movement angle is less than the angle of the pixel.

11. The apparatus of claim 10 , further comprising a storage unit which set and stores a rotation angle of hue of each of the regions using angle areas about a central point.

12. The apparatus of claim 10 , wherein the determiner calculates the coordinates of the hue values Cr and Cb of the pixel, rotates the coordinates by 45°, and determines the region by determining hue polarities of the coordinates and the coordinates rotated by 45°.

13. The apparatus of claim 10 , wherein the determiner calculates the angle of the pixel by normalizing a ratio between the hue values Cr and Cb.

14. The apparatus of claim 10 , wherein the determiner calculates the angle of the pixel using an equation of

θ

≅

sin

⁢

⁢

θ

≅

tan

⁢

⁢

θ

=

Cr

Cb

.

15. The apparatus of claim 10 , wherein the interpolator calculates the movement angle by searching a movement angle which is preset as corresponding to an absolute value of a difference between the rotation angle set for the determined region and the rotation angle set for the adjacent region.

16. The apparatus of claim 10 , wherein if the interpolator determines that the interpolation is not to be performed, the movement unit moves the pixel by the rotation angle set for the determined region.

17. The apparatus of claim 10 , wherein the interpolator calculates an interpolation ratio by using the movement angle and the angle of the pixel and moves the pixel by the interpolation ratio.

18. The apparatus of claim 10 , wherein the interpolator calculates the interpolation angle by an equation as follows:

the interpolation angle=(the rotation angle set for the determined region(128−ratio)+the rotation angle set for the adjacent region×ratio)/128,

where the ration is (the angle of the pixel/the movement angle)×128.