cOMS/Image/ImageUtils.h

/**
 * Karaka
 *
 * @package   Image
 * @copyright Dennis Eichhorn
 * @license   OMS License 1.0
 * @version   1.0.0
 * @link      https://karaka.app
 */
#ifndef IMAGE_IMAGE_UTILS_H
#define IMAGE_IMAGE_UTILS_H

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

namespace Image {
    class ImageUtils {
        private:

        public:
            static inline
            float lightnessFromRgb(int r, int g, int b)
            {
                float vR = r / 255.0;
                float vG = g / 255.0;
                float vB = b / 255.0;

                float lR = vR <= 0.04045 ? vR / 12.92 : pow(((vR + 0.055) / 1.055), 2.4);
                float lG = vG <= 0.04045 ? vG / 12.92 : pow(((vG + 0.055) / 1.055), 2.4);
                float lB = vB <= 0.04045 ? vB / 12.92 : pow(((vB + 0.055) / 1.055), 2.4);

                float y     = 0.2126 * lR + 0.7152 * lG + 0.0722 * lB;
                float lStar = y <= 216.0 / 24389.0 ? y * 24389.0 / 27.0 : pow(y, (1.0 / 3.0)) * 116.0 - 16.0;

                return lStar / 100.0;
            }

            static inline
            int rgbToInt(int r, int g, int b)
            {
                int rgb = r;
                rgb     = (rgb << 8) + g;
                rgb     = (rgb << 8) + b;

                return rgb;
            }
    };
}

#endif