def TileBounds(tx, ty, zoom):
		res = 180 / 256.0 / 2**zoom
		return (
			tx*256*res - 180,
			ty*256*res - 90,
			(tx+1)*256*res - 180,
			(ty+1)*256*res - 90
		)
Returns bounds of the given tile
dataset/ETHPy150Open Ecotrust/create-utfgrids/globalmaptiles.py/GlobalGeodetic.TileBounds