Java CMYK to RGB Converter

Almost everyone knows the RGB color model, red, green and blue, especially as a software engineer. It's widely applied in many industries. The CMYK, stands for "Cyan Magenta Yellow Black", is mostly used in paper print. Today we are going to create a java program to convert a color from CMYK to RGB.

Question

CMYK to RGB color matching. Write a java program CMYKtoRGB that reads in four command line inputs C, M, Y, and K between 0 and 100, and prints the corresponding RGB parameters. Devise the appropriate formula by "inverting" the RGB to CMYK conversion formula.

Implementing Steps

The CMYK color model has 4 color values from 0 to 100, and the RGB color model has 3 color values from 0 to 255. The formula is very simple and listed in the code.

Here is the formula

R = 255 × (1-C) × (1-K)
G = 255 × (1-M) × (1-K)
B = 255 × (1-Y) × (1-K)

Here the goes the key steps:

1. Pass 4 CMYK values as command line parameters
2. Calculate the RGB values according to the CMYK values
3. Print the RGB values as String

Solution

/******************************************************************************
 *  Compilation:  javac CmykRgbConverter.java
 *  Execution:    java CmykRgbConverter c m y k
 *  
 *  Convert color values from CMYK to RGB format.
 *  
 *  %  java CmykRgbConverter 0 0 0 0
 *  [255, 255, 255]
 *  
 *  %  java CmykRgbConverter 0 0 0 100
 *  [0, 0, 0]
 *  
 *  %  java CmykRgbConverter 100 0 100 0
 *  [0, 255, 0]
 *  
 ******************************************************************************/

import java.util.Arrays;

public class CmykRgbConverter {
    public static void main(String[] args) {
        int[] rgb = cmykToRgb(
            Integer.parseInt(args[0]),
            Integer.parseInt(args[1]),
            Integer.parseInt(args[2]),
            Integer.parseInt(args[3])
        );

        System.out.println(Arrays.toString(rgb));
    }

    private static int[] cmykToRgb(int c, int m, int y, int k) {
        int r = 255 * (1 - c/100) * (1 - k/100);
        int g = 255 * (1 - m/100) * (1 - k/100);
        int b = 255 * (1 - y/100) * (1 - k/100);
        int[] rgb = new int[]{ r, g, b };

        return rgb;
    }
}

Output

-> javac CmykRgbConverter.java

-> java CmykRgbConverter 0 0 0 0
[255, 255, 255]

-> java CmykRgbConverter 0 100 100 0
[255, 0, 0]

-> java CmykRgbConverter 0 100 100 100
[0, 0, 0]

The code above is a very simple java code of how to convert a pixel color value from CMYK to RGB.