raptor00

[DllImport("Kernel32.dll", EntryPoint = "RtlMoveMemory", SetLastError = false)]
private static unsafe extern void MoveMemory(void* dest, void* src, int size);

public static Bitmap FastCrop(Bitmap image, Rectangle area)
{
    //Create the new bitmap
    Bitmap result = new Bitmap(area.Width,
                       area.Height, image.PixelFormat);

    unsafe
    {
        //lock the bits for both bitmaps to
        //allow direct access by pointer
        BitmapData bmd = image.LockBits(area,
            ImageLockMode.ReadOnly, image.PixelFormat);
        BitmapData bmdResult = result.LockBits(
            new Rectangle(0, 0, area.Width, area.Height),
            ImageLockMode.WriteOnly, result.PixelFormat);

        int pixelSize =
            Image.GetPixelFormatSize(image.PixelFormat) / 8;

        //Copy the memory from each row in
        //the first bitmap to second
        for (int y = 0; y < bmd.Height; y++)
        {
            byte* to = (byte*)bmdResult.Scan0
                           + (y * bmdResult.Stride);
            byte* from = (byte*)bmd.Scan0 + (y * bmd.Stride);

            MoveMemory(to, from, area.Width * pixelSize);
        }

        image.UnlockBits(bmd);
        result.UnlockBits(bmdResult);
    }

    return result;
}