python sepia filter
sepiaRed = 0.393 * originalRed + 0.769 * originalGreen + 0.189 * originalBlue
sepiaGreen = 0.349 * originalRed + 0.686 * originalGreen + 0.168 * originalBlue
sepiaBlue = 0.272 * originalRed + 0.534 * originalGreen + 0.131 * originalBlue