System.Drawing.Imaging.ImageAttributes.ClearColorMatrix C# (CSharp) Method

		public void ClearColorMatrix()
		{
			ClearColorMatrix(ColorAdjustType.Default);
		}

        /// <summary>
        /// change brightness, contrast and/or gamma of a bitmap
        /// (see http://stackoverflow.com/questions/15408607/adjust-brightness-contrast-and-gamma-of-an-image)
        /// </summary>
        /// <param name="originalImage">image to process</param>
        /// <param name="brightness">new brightness (1.0 = no changes, 0.0 to 2.0)</param>
        /// <param name="contrast">new contrast (1.0 = no changes)</param>
        /// <param name="gamma">new gamma (1.0 = no changes)</param>
        /// <returns></returns>
        static internal Bitmap adjustBitmap(Bitmap originalImage, float brightness = 1.0f, float contrast = 1.0f, float gamma = 1.0f)
        {
            Bitmap adjustedImage;
            ImageAttributes imageAttributes;
            Graphics g;
            float adjustedBrightness;

            adjustedBrightness = brightness - 1.0f;

            // create matrix that will brighten and contrast the image
            float[][] ptsArray ={
                    new float[] {contrast, 0, 0, 0, 0},     // scale red
                    new float[] {0, contrast, 0, 0, 0},     // scale green
                    new float[] {0, 0, contrast, 0, 0},     // scale blue
                    new float[] {0, 0, 0, 1.0f, 0},         // don't scale alpha
                    new float[] {adjustedBrightness, adjustedBrightness, adjustedBrightness, 0, 1}};

            imageAttributes = new ImageAttributes();
            imageAttributes.ClearColorMatrix();
            imageAttributes.SetColorMatrix(new ColorMatrix(ptsArray), ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
            imageAttributes.SetGamma(gamma, ColorAdjustType.Bitmap);

            adjustedImage   = new Bitmap(originalImage.Width, originalImage.Height);
            g               = Graphics.FromImage(adjustedImage);

            g.DrawImage(originalImage, new Rectangle(0,0,adjustedImage.Width,adjustedImage.Height),
                        0,0,originalImage.Width,originalImage.Height,
                        GraphicsUnit.Pixel, imageAttributes);

            g.Dispose();

            return adjustedImage;
        }