Lines Matching defs:wb
868 float wr = 0.2126, wg = 0.7152, wb = 0.0722; // ITU709 recommended constants
871 float y = wr * r + wg * g + wb * b;
872 float u = 0.5 * ((b - y) / (1.0 - wb)) + 0.5;
890 // u = 0.5 * ((b - y) / (1.0 - wb)) + 0.5
891 // 0.5 * ((b - y) / (1.0 - wb)) = u - 0.5
892 // (b - y) / (1.0 - wb) = 2 * (u - 0.5)
893 // b - y = 2 * (u - 0.5) * (1.0 - wb)
894 // b = 2 * (u - 0.5) * (1.0 - wb) + y
902 // y = wr * r + wg * g + wb * b
903 // wr * r + wg * g + wb * b = y
904 // wg * g = y - wr * r - wb * b
905 // g = (y - wr * r - wb * b) / wg
909 float b = 2.0 * (u - 0.5) * (1.0 - wb) + y;
910 float g = (y - wr * r - wb * b) / wg;
