Question

How to convert RGB to CMYK in C

Answer 1

// CMYK = Cyan, Magenta, Yellow, Key(black)
// RGB = Red, Green, Blue

#include <stdio.h>
#include <math.h>

struct CMYK {
    float C;
    float M;
    float Y;
    float K;
};

struct CMYK RGBtoCMYK(float R, float G, float B) {
    struct CMYK cmyk;

    if (R == 0 && G == 0 && B == 0) {
        cmyk.C = 0;
        cmyk.M = 0;
        cmyk.Y = 0;
        cmyk.K = 1;

        return cmyk;
    }

    R = R / 255;
    G = G / 255;
    B = B / 255;

    float max = R;

    if (max < G)
        max = G;
    if (max < B)
        max = B;

    float white = max;

    cmyk.C = ((white - R) / white) * 100;
    cmyk.M = ((white - G) / white) * 100;
    cmyk.Y = ((white - B) / white) * 100;
    cmyk.K = (1.0f - white) * 100;

    return cmyk;
}

int main() {
    struct CMYK cmyk = RGBtoCMYK(245.0f, 213.0f, 0.0f);

    printf("Cyan: %.0f\n", cmyk.C);
    printf("Magenta: %.0f\n", cmyk.M);
    printf("Yellow: %.0f\n", cmyk.Y);
    printf("Black: %.0f\n", cmyk.K);
}




/*
run:

Cyan: 0
Magenta: 13
Yellow: 100
Black: 4

*/

 

70+ SQL courses for beginners and professionals