public partial class Grayscale

    {

        #region Bitmap ToGrayscale(Bitmap bmColor)

        /// <summary>

        /// Charles Petzold's method.\n

        /// Bitmap to Grayscale Bitmap

        /// </summary>

        /// <param name="bmColor"></param>

        /// <returns></returns>

        public static unsafe Bitmap ToGrayscale(Bitmap bmColor)

        {

            if (!IsGrayscale(bmColor))

            {

                int cx = bmColor.Width;

                int cy = bmColor.Height;

​

                Bitmap bmMono = new Bitmap(cx, cy, PixelFormat.Format8bppIndexed);

                bmMono.SetResolution(bmColor.HorizontalResolution,

                                     bmColor.VerticalResolution);

​

                ///////////////////////////////////////

                // Set grayscale palette

                ///////////////////////////////////////

                ColorPalette colorPalette = bmMono.Palette;

                for (int i = 0; i < colorPalette.Entries.Length; i++)

                {

                    colorPalette.Entries[i] = Color.FromArgb(i, i, i);

                }

​

                bmMono.Palette = colorPalette;

​

                BitmapData bmd = bmMono.LockBits(

                    new Rectangle(Point.Empty, bmMono.Size),

                    ImageLockMode.WriteOnly, PixelFormat.Format8bppIndexed);

​

                Byte* pPixel = (Byte*)bmd.Scan0;

​

                for (int y = 0; y < cy; y++)

                {

                    for (int x = 0; x < cx; x++)

                    {

                        Color clr = bmColor.GetPixel(x, y);

​

                        Byte byPixel = (byte)((30 * clr.R + 59 * clr.G + 11 * clr.B) / 100);

​

                        pPixel[x] = byPixel;

                    }

​

                    pPixel += bmd.Stride;

                }

​

                bmMono.UnlockBits(bmd);

​

                return bmMono;

            }

            else

            {

                throw new Exception("Already a grayscale");

            }

        }  

        #endregion

​

        /// <summary>

        /// Bitmap to Grayscale Integer array.

        /// </summary>

        /// <param name="InputImageBitmap"></param>

        /// <returns></returns>

        public static int[,] ToGrayscaleInteger(Bitmap InputImageBitmap)

        {

            if (!IsGrayscale(InputImageBitmap))

            {

                Bitmap bmp = Grayscale.ToGrayscale(InputImageBitmap);

​

                return ImageDataConverter.ToInteger(bmp);

            }

            else

            {

                throw new Exception("Already a grayscale");

            }

        }

​

        public static Bitmap CreateImage(int width, int height)

        {

            // create new image

            Bitmap image = new Bitmap(width, height, PixelFormat.Format8bppIndexed);

            // set palette to grayscale

            SetGrayscalePalette(image);

            // return new image

            return image;

        }

​

        public static Bitmap CreateImage(int width, int height, Color fill)

        {

            // create new image

            Bitmap image = CreateImage(width, height);

            // set palette to grayscale

            image = Fill(image, fill);

            // return new image

            return image;

        }

​

        public static Bitmap Fill(Bitmap image, Color fill)

        {

            BitmapLocker locker = new BitmapLocker(image);

            locker.Lock();

            for (int i = 0; i < image.Width; i++)

            {

                for (int j = 0; j < image.Height; j++)

                {

                    locker.SetPixel(i, j, fill);

                }

            }

​

            locker.Unlock();

​

            return image;

        }

​

        public static void SetGrayscalePalette(Bitmap image)

        {

            // check pixel format

            if (image.PixelFormat == PixelFormat.Format8bppIndexed)

            {

                // get palette

                ColorPalette cp = image.Palette;

​

                // init palette

                for (int i = 0; i < 256; i++)

                {

                    cp.Entries[i] = Color.FromArgb(i, i, i);

                }

​

                // set palette back

                image.Palette = cp;

            }

            else

            {

                throw new Exception("8 bit grayscaleImage required");

            }

        }

​

        public static bool IsGrayscale(Bitmap bitmap)

        {

            return bitmap.PixelFormat == PixelFormat.Format8bppIndexed ? true : false;

        }

​

        public static bool IsDimensionsPowerOf2(Bitmap bitmap)

        {

            return (Tools.IsPowerOf2(bitmap.Width) && Tools.IsPowerOf2(bitmap.Height));

        }

    }