def PixelsToMeters( px, py, zoom):
	import math
	tileSize = 256
	initialResolution = 2 * math.pi * 6378137 / tileSize
	# 156543.03392804062 for tileSize 256 pixels
	originShift = 2 * math.pi * 6378137 / 2.0
# 20037508.342789244
	res = initialResolution/(2**zoom)
	mx = px * res - originShift
	my = py * res - originShift
	return mx, my