Hue adjusting device

• US 20080013135A1
• Filed: 05/08/2007
• Published: 01/17/2008
• Est. Priority Date: 07/17/2006
• Status: Active Grant

• Current Assignee: Marketech International Corp.
• Original Assignee: Marketech International Corp.
• Inventors: Tsai, Tsan-Hung, Kao, Hsu-Chia, Shan, Yi-Chia, Hsu, Kai-Hsiang
• Granted Patent: US 7,773,259 B2
• Time in Patent Office: Days
• US Class Current: 358/520
• CPC Class Codes: H04N 1/6075 Corrections to the hue

Abstract

The invention provides a hue adjusting device. When one color axis including different hues is being adjusted by the user, the hue adjusting device will rotate each of the different hue angles in different rotation angles. Accordingly, the color of an image adjusted by the invention will be smoother than the prior art. Namely, the image quality can be improved.

Claims

1. A hue adjusting device, an image signal being inputted to a display system, the image signal being composed of N pixels, N being a natural number, each of the N pixels of the image signal being converted to the one comprising a first color component and a second color component, the hue adjusting device being used to adjust a hue angle of the i-th pixel of the image signal, i being an integer index ranging from 1 to N, the hue angle being obtained by converting the first color component and the second color component, and the hue adjusting device comprising:

a first memory unit for storing a first look-up table, the first look-up table recording a plurality of hue angles, a plurality of adjusting parameters, and a plurality of rotation angles, each of the rotation angles being corresponding to one of the hue angles and one of the adjusting parameters respectively, and the plurality of hue angles also being divided into a plurality of color axes;

a second memory unit for storing a second look-up table;

a first processing unit for downloading a plurality of corresponding rotation angles from the first look-up table to the second look-up table according to a user-selected color axis and a user-selected adjusting parameter, wherein the user-selected color axis is the one selected from the color axes, and the user-selected adjusting parameter is the one selected from the adjusting parameters of the first look-up table; and

a second processing unit for retrieving a rotation angle from the second look-up table according to the hue angle of the i-th pixel and for readjusting the first color component and the second color component of the i-th pixel, such that the hue angle of the i-th pixel is readjusted.

2. The hue adjusting device of claim 1, wherein the second memory unit stores a third look-up table, the third look-up table records a plurality of sine values and cosine values corresponding to the rotation angles.

3. The hue adjusting device of claim 2, wherein the second processing unit readjusts the first color component and the second color component of the i-th pixel according to the following formulas:

C1_adj=C1·

cos(d)−

C2·

sin(d)

C2_adj=C1·

sin(d)+C2·

cos(d)

wherein C1 represents the first color component, C2 represents the second color component, d represents the retrieved rotation angle, C1_adj represents the readjusted first color component, and C2_adj represents the readjusted second color component, the sine value and cosine value are selected from the third look-up table.

4. The hue adjusting device of claim 1, wherein the display system comprises a hue dividing device coupled with the hue adjusting device, the hue dividing device stores a fourth look-up table, the fourth look-up table records a plurality of boundaries for dividing the hue angles into the color axes.

5. The hue adjusting device of claim 1, wherein the first memory unit is a non-volatile and rewritable storing device, the second memory unit is a random access memory (RAM) of an IC.

6. The hue adjusting device of claim 1, wherein the first color component and the second color component comply with one of the following color spaces:

YCbCr, YUV, YIQ, HIS, HSV, and CIELab.