[ScanLine]

    Graphics::TBitmap* GrayBMP = new Graphics::TBitmap();
    GrayBMP->LoadFromFile("test.bmp");
    Byte* GrayPtr = NULL;
    for (int y=0; yHeight ;y  )
    {
      GrayPtr = (Byte*)GrayBMP->ScanLine[y];
      for (int x=0; xWidth; x  )
      {
        Byte Gray = (GrayPtr[x*3] GrayPtr[x*3 1] GrayPtr[x*3 2])/3;
        GrayPtr[x*3]=Gray;
        GrayPtr[x*3 1]=Gray;
        GrayPtr[x*3 2]=Gray;
      }
    }
    Image1->Picture->Assign(GrayBMP);
    delete GrayBMP;