Listing 3. Cycle through the bitmap negating each pixel. 
  for(int row = 0;row < 330;row++){
    for(int column = 0;column < 324;column++){
      pixel = getpixel(picA,column,row);
      red = getr(pixel);
      green = getg(pixel);
      blue = getb(pixel);
      putpixel(picA,column,row,makecol(
                             255-red,255-green,255-blue));
    }//end loop row
  }//end loop on column