if __name__=='__main__':
 oldlzts = 36

 for zoom in [2,3]:
  oldtilesize = getTileSize(zoom, lzts=oldlzts)
  newtilesize = getTileSize(zoom, lzts=oldlzts/2)
  try: os.mkdir('n/' + str(zoom))
  except: pass
  for dir in os.walk(str(zoom)):
   print 'processing', dir[0]
   for file in dir[2]:
    try: row, col = int(file.split('_')[0]), int(file.split('_')[1].split('x')[0])
    except: continue
    b = _get_tile_bbox(col, row, oldtilesize)
    t = {}
    t[0] = b.north, b.west
    t[1] = b.north, b.west + (b.west - b.east) / 2
    t[2] = b.north - abs(b.north - b.south) / 2, b.west
    t[3] = b.north - abs(b.north - b.south) / 2, b.west + abs(b.west - b.east) / 2
    for i in [0, 1, 2, 3]:
     t_row = getRowFromLat(t[i][0], newtilesize)
     t_col = getColFromLng(t[i][1], newtilesize)
     try: os.mkdir('n/%i/%i' % (zoom, t_row))
     except: pass
     src = '%i/%04.i/%04.i_%04.ix%i.jpg' % (zoom, row, row, col, i)
     dst = 'n/%i/%i/%i_%i.jpg' % (zoom, t_row, t_row, t_col)
     copy(src, dst)