我想知道增加或减少一个RGB颜色饱和度的算法
例如,如果我有颜色rgb(200,30,40)(红色)函数存根
function Saturation(color,factor) where color.r = 200,color.g= 30 and color.b=40
任何人都知道一个图书馆或有一个代码片段吗？
解决方法
按照巴厘岛巴洛的建议,我提出了：
RGBtoHSV= function(color) {
var r,g,b,h,s,v;
r= color[0];
g= color[1];
b= color[2];
min = Math.min( r,b );
max = Math.max( r,b );
v = max;
delta = max - min;
if( max != 0 )
s = delta / max; // s
else {
// r = g = b = 0 // s = 0,v is undefined
s = 0;
h = -1;
return [h,undefined];
}
if( r === max )
h = ( g - b ) / delta; // between yellow & magenta
else if( g === max )
h = 2 + ( b - r ) / delta; // between cyan & yellow
else
h = 4 + ( r - g ) / delta; // between magenta & cyan
h *= 60; // degrees
if( h < 0 )
h += 360;
if ( isNaN(h) )
h = 0;
return [h,v];
};
HSVtoRGB= function(color) {
var i;
var h,v,r,b;
h= color[0];
s= color[1];
v= color[2];
if(s === 0 ) {
// achromatic (grey)
r = g = b = v;
return [r,b];
}
h /= 60; // sector 0 to 5
i = Math.floor( h );
f = h - i; // factorial part of h
p = v * ( 1 - s );
q = v * ( 1 - s * f );
t = v * ( 1 - s * ( 1 - f ) );
switch( i ) {
case 0:
r = v;
g = t;
b = p;
break;
case 1:
r = q;
g = v;
b = p;
break;
case 2:
r = p;
g = v;
b = t;
break;
case 3:
r = p;
g = q;
b = v;
break;
case 4:
r = t;
g = p;
b = v;
break;
default: // case 5:
r = v;
g = p;
b = q;
break;
}
return [r,b];
}
通过转换为HSV(色调,饱和度和值)格式,您可以以这种方式手动更改S组件：
var hsv= RGBtoHSV ([200,100,100]); alert(hsv) hsv[1] *= 1.5; alert(hsv) var rgb= HSVtoRGB(hsv); alert(rgb); //new color
