Apparatus and method for adjusting saturation image

Abstract

A method for adjusting a degree of saturation of a target pixel is provided. In a first color space, the target pixel is represented by a brightness factor and a set of color factors. Based on the set of color factors, the method first generates an original saturation and a hue factor. Then, selectively according to the brightness factor, the hue factor, and the original saturation, an adjusting gain is generated. The method, according to this invention, multiplies the original saturation by the adjusting gain to generate a new saturation for the target pixel.

Description

BRIEF DESCRIPTION OF THE APPENDED DRAWINGS

FIG. 1 is the flowchart of the image adjusting method in the first preferred embodiment according to this invention.

FIG. 2 is the flowchart of the image adjusting method in the second preferred embodiment according to this invention.

FIG. 3 is the block diagram of the image adjusting apparatus in the third preferred embodiment according to this invention.

FIG. 4 is the block diagram of the image adjusting apparatus in the fourth preferred embodiment according to this invention.

FIG. 5 is the block diagram of the image adjusting apparatus in the fifth preferred embodiment according to this invention.

Claims

1. A method for adjusting a saturation degree of a target pixel, in a first color space, the target pixel being represented as a brightness factor and a set of color factors, the method comprising: (a) according to the set of color factors, generating an original saturation degree and a hue factor;(b) selectively according to the brightness factor, the hue factor, and the original saturation degree, generating an adjusting gain; and(c) multiplying the original saturation degree by the adjusting gain to generate a new saturation degree for the target pixel.

2. The method of claim 1, wherein the first color space is a YUV color space, a YIQ color space, a YCbCr color space, or a CIELab color space.

3. The method of claim 1, wherein the brightness factor and the set of color factors are transformed from an RGB color space.

4. The method of claim 1, wherein the set of color factors comprises a first color factor (a) and a second color factor (b); in the step (a), the original saturation degree is equal to (a2+b2)0.5, and the hue factor is equal to tan−1(b/a).

5. The method of claim 1, wherein in the step (b), the adjusting gain is selected from a look-up table selectively according to the brightness factor, the hue factor, and the original saturation degree.

6. A method for adjusting a saturation degree of a target pixel, in a first color space, the target pixel being represented as a brightness factor and a set of color factors, the method comprising: (a) according to the set of color factors, generating an original saturation degree;(b) selectively according to the brightness factor and the original saturation degree, generating an adjusting gain; and(c) multiplying the original saturation degree by the adjusting gain to generate a new saturation degree for the target pixel.

7. The method of claim 6, wherein the first color space is a YUV color space, a YIQ color space, a YCbCr color space, or a CIELab color space.

8. The method of claim 6, wherein the brightness factor and the set of color factors are transformed from an RGB color space.

9. The method of claim 6, wherein the set of color factors comprises a first color factor (a) and a second color factor (b), and the original saturation degree is equal to (a2+b2)0.5 in the step (a).

10. The method of claim 6, wherein in the step (b), the adjusting gain is selected from a look-up table selectively according to the brightness factor and the original saturation degree.

11. A method for generating a saturation characteristic of an image, the image comprising M pixels, M being a positive integer, each of the M pixels respectively having a brightness factor and a set of color factors, the method comprising: (a) according to the respective set of color factors, generating an original saturation degree and a hue factor for each of the M pixels, respectively;(b) selectively according to the respective brightness factor, the respective hue factor, and the respective original saturation degree, generating an adjusting gain for each of the M pixels, respectively;(c) multiplying the respective original saturation degree by the respective adjusting gain to generate a new saturation degree for each of the M pixels, respectively; and(d) according to the new saturation degrees of the M pixels, generating a statistical result as the saturation characteristic of the image.

12. An apparatus for adjusting a saturation degree of a target pixel, in a first color space, the target pixel being represented as a brightness factor and a set of color factors, the apparatus comprising: a calculating module for generating an original saturation degree and a hue factor according to the set of color factors;a generating module for generating an adjusting gain selectively according to the brightness factor, the hue factor, and the original saturation degree; anda multiplying module for multiplying the original saturation degree by the adjusting gain to generate a new saturation degree for the target pixel.

13. The apparatus of claim 12, wherein the first color space is a YUV color space, a YIQ color space, a YCbCr color space, or a CIELab color space.

14. The apparatus of claim 12, wherein the brightness factor and the set of color factors are transformed from an RGB color space.

15. The apparatus of claim 12, wherein the set of color factors comprises a first color factor (a) and a second color factor (b), and the calculating module generates the original saturation degree by calculating (a2+b2)0.5 and generates the hue factor by calculating tan−1(b/a).

16. The apparatus of claim 12, wherein the generating module comprises a look-up table and the adjusting gain is selected from the look-up table selectively according to the brightness factor, the hue factor, and the original saturation degree.

17. An apparatus for adjusting a saturation degree of a target pixel, in a first color space, the target pixel being represented as a brightness factor and a set of color factors, the apparatus comprising: a calculating module for generating an original saturation degree according to the set of color factors;a generating module for generating an adjusting gain selectively according to the brightness factor and the original saturation degree; anda multiplying module for multiplying the original saturation degree by the adjusting gain to generate a new saturation degree for the target pixel.

18. The apparatus of claim 17, wherein the first color space is a YUV color space, a YIQ color space, a YCbCr color space, or a CIELab color space.

19. The apparatus of claim 17, wherein the brightness factor and the set of color factors are transformed from an RGB color space.

20. The apparatus of claim 17, wherein the set of color factors comprises a first color factor (a) and a second color factor (b), and the calculating module generates the original saturation degree by calculating (a2+b2)0.5 and generates the hue factor by calculating tan−1(b/a).

21. The apparatus of claim 17, wherein the generating module comprises a look-up table and the adjusting gain is selected from the look-up table selectively according to the brightness factor, the hue factor, and the original saturation degree.

22. An apparatus for generating a saturation characteristic of an image, the image comprising M pixels, M being a positive integer, each of the M pixels respectively having a brightness factor and a set of color factors, the apparatus comprising: a calculating module, according to the respective set of color factors, the calculating module generating an original saturation degree and a hue factor for each of the M pixels, respectively;a generating module, selectively according to the respective brightness factor, the respective hue factor, and the respective original saturation degree, the generating module generating an adjusting gain for each of the M pixels, respectively;a multiplying module for multiplying the respective original saturation degree by the respective adjusting gain to generate a new saturation degree for each of the M pixels, respectively; anda statistic module, according to the new saturation degrees of the M pixels, the statistic module generating a statistical result as the saturation characteristic of the image.

23. A method for adjusting a saturation degree of a target pixel, in a first color space, the target pixel being represented as an original saturation degree, a hue factor, and a brightness factor, the method comprising: (a) selectively according to the original saturation degree, the hue factor, and the brightness factor, generating an adjusting gain; and(b) multiplying the original saturation degree by the adjusting gain to generate a new saturation degree for the target pixel.

24. The method of claim 23, wherein the first color space is a HSV color space or a HSI color space.

25. The method of claim 23, wherein the original saturation degree, the hue factor, and the brightness factor are transformed from an RGB color space.

26. The method of claim 23, wherein in the step (a), the adjusting gain is selected from a look-up table selectively according to the original saturation degree, the hue factor, and the brightness factor.