RGB-to-CMYK Color Conversion
JavaScript FAQ |
JavaScript Colors FAQ
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Question: How do I convert a color from RGB model to CMYK model in JavaScript?
Answer: The CMYK (Cyan, Magenta, Yellow, blacK) color model is widely used in printed media – just as the RGB (Red, Green, Blue) model used for on-screen colors. Below is a simple RGB-to-CMYK color converter function. Try it now – input the RGB values (in the range 0 to 255) and click Convert to CMYK:
Here is the JavaScript source code of the RGB-to-CMYK converter function.
function rgb2cmyk (r,g,b) {
var computedC = 0;
var computedM = 0;
var computedY = 0;
var computedK = 0;
//remove spaces from input RGB values, convert to int
var r = parseInt( (''+r).replace(/\s/g,''),10 );
var g = parseInt( (''+g).replace(/\s/g,''),10 );
var b = parseInt( (''+b).replace(/\s/g,''),10 );
if ( r==null || g==null || b==null ||
isNaN(r) || isNaN(g)|| isNaN(b) )
{
alert ('Please enter numeric RGB values!');
return;
}
if (r<0 || g<0 || b<0 || r>255 || g>255 || b>255) {
alert ('RGB values must be in the range 0 to 255.');
return;
}
// BLACK
if (r==0 && g==0 && b==0) {
computedK = 1;
return [0,0,0,1];
}
computedC = 1 - (r/255);
computedM = 1 - (g/255);
computedY = 1 - (b/255);
var minCMY = Math.min(computedC,
Math.min(computedM,computedY));
computedC = (computedC - minCMY) / (1 - minCMY) ;
computedM = (computedM - minCMY) / (1 - minCMY) ;
computedY = (computedY - minCMY) / (1 - minCMY) ;
computedK = minCMY;
return [computedC,computedM,computedY,computedK];
}
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