public static Bitmap FastNullTransform(Image inputImage)
        {
            Bitmap outputBitmap = new Bitmap(inputImage.Width, inputImage.Height);

            ImageAttributes attributes = new ImageAttributes();

            ColorMatrix colorMatrix = new ColorMatrix(new float[][] {
                        new float[] {1, 0, 0, 0, 0},
                        new float[] {0, 1, 0, 0, 0},
                        new float[] {0, 0, 1, 0, 0},
                        new float[] {0, 0, 0, 1, 0},
                        new float[] {0, 0, 0, 0, 1}
                        }
            );

            attributes.SetColorMatrix(colorMatrix);
            
            Graphics outputGraphics = Graphics.FromImage(outputBitmap);
            Rectangle rectInput = new Rectangle(0, 0, inputImage.Width, inputImage.Height);

            outputGraphics.DrawImage(inputImage, rectInput, 0, 0, inputImage.Width, inputImage.Height, GraphicsUnit.Pixel, attributes);
            outputGraphics.Dispose();

            return outputBitmap;
        }