Color coordinate space structure and color quantizing and variable gray area designating method therein
AssigneeLG Electronics Inc.
InventorsHyeon Jun Kim, Jin Soo Lee
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Abstract
A color space structure and quantizing method is disclosed. Upon conversion from the RGB color space into HSV color space, a difference value S′ (S′=max−min) is obtained by varying the maximum value of the saturation S in accordance with the value V resulting in a HS′V color space where the difference value S′ forms one axis of the color coordinate, such that all of color areas are evenly distributed and the variation of color is uniformly displayed.
Claims20
A method for converting an input color to a HS′V color model having a reverse conical shape around a V axis and the apex at the bottom, the method comprising:
- defining a hue H as the angle around the V axis;
- defining a saturation S′ as a normal vector of the V axis in the direction from the V axis to the circumference C of the cone;
- and
- defining a value V as a vector in the positive direction of the V axis;
- wherein the saturation S′ ranges between 0 and 1, and wherein the saturation S′ of the color model is converted from a RGB color model with (r,g,b) color values by the following equations:
- max=the maximum value from input r,g,b
- min=the minimum value from input r,g,b
- S′=(max−min)/max*max=s*max=max−min.
A quantization method for the HS′V color space comprising:
- (a) designating the gray areas of the HS′V color space, wherein the gray areas change shape for different values of the V color space;
- (b) color quantization of the HS′V color space;
- and
- (c) index mapping the color information outside the gray areas within each quantized areas to an identical value.
A method for designating gray areas for a color space defined by hue, saturation, and value, comprising:
- designating gray areas according to a reference value, wherein said reference value is proportional to the luminance Y of the hue in the color space, wherein a proportional representation of each of at least three colors determining the color space changes according to the hue;
- storing the designated gray areas;
- wherein a gray area value τgray is not constant and changes according to the hue, and wherein a saturation value (S) less than τgray is within the gray area and the saturation value S not less than the τgray is not within the gray area.
A color processing system, comprising:
- a processor that receives input colors and converts the input color to a corresponding second input color when the input color falls outside a gray area of a color model;
- and
- a display that displays the converted second color, wherein the processor converts the input color using a HS′V color conversion model having the shape of a reverse conical shape around a value V axis with the apex at the bottom, wherein the HS′V color conversion model comprises,
- a hue H defined as the angle around the V axis,
- a saturation S′ defined as a normal vector of the V axis in the direction from the V axis to the circumference C of the cone, wherein the saturation S′ ranges between 0 and 1, and wherein the saturation S′ of the color conversion model is converted from a RGB color model with (r,g,b) color values by the following equations:
- max=the maximum value from input r, g, b
- min=the minimum value from input r, g, b
- S′=(max−min)/max*max=s*max=max−min;
- and
- wherein the value V is defined as a vector in the positive direction of the V axis.
Dependencies are inferred from the claim text.