public static Bitmap Monochromatic(Bitmap sourceImage)
        {
            var result = new Bitmap(sourceImage.Width,sourceImage.Height);

            for (var i = 0; i < sourceImage.Height - 1; i++)
            for (var j = 0; j < sourceImage.Width - 1; j++)
            {
                var pixel = sourceImage.GetPixel(j, i);
                var colorValue = (int)(0.3 * pixel.R + 0.6 * pixel.G + 0.1 * pixel.B);
                var newColor = Color.FromArgb(colorValue, colorValue, colorValue);
                result.SetPixel(j,i,newColor);
            }

            return result;
        }