
/*Insert this as a function anywere, I used it in a seperate DLL to keep my form code clean.  Just pass the Bitmap and the picture box to show it in to the function*/
public void greyscale(Bitmap bmp, PictureBox picBox)
        {
            BitmapData data = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height),
                ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
            unsafe
            {
                byte* imgPtr = (byte*)(data.Scan0);
                byte red, green, blue;
                for (int i = 0; i < data.Height; i++)
                {
                    for (int j = 0; j < data.Width; j++)
                    {
                        blue = imgPtr[0];
                        green = imgPtr[1];
                        red = imgPtr[2];

                        imgPtr[0] = imgPtr[1] = imgPtr[2] = 
                           (byte)(.299 * red
                            + .587 * green
                            + .114 * blue);
                        imgPtr += 3;
                    }
                    imgPtr += data.Stride - data.Width * 3;
                }

            }
            bmp.UnlockBits(data);
            picBox.Image = bmp;
        }