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A python script to download high resolution Google map images given a longitude, latitude and zoom level.
#!/usr/bin/python
# GoogleMapDownloader.py
# Created by Hayden Eskriett [http://eskriett.com]
#
# A script which when given a longitude, latitude and zoom level downloads a
# high resolution google map
# Find the associated blog post at: http://blog.eskriett.com/2013/07/19/downloading-google-maps/
import urllib
import Image
import os
import math
class GoogleMapDownloader:
"""
A class which generates high resolution google maps images given
a longitude, latitude and zoom level
"""
def __init__(self, lat, lng, zoom=12):
"""
GoogleMapDownloader Constructor
Args:
lat: The latitude of the location required
lng: The longitude of the location required
zoom: The zoom level of the location required, ranges from 0 - 23
defaults to 12
"""
self._lat = lat
self._lng = lng
self._zoom = zoom
def getXY(self):
"""
Generates an X,Y tile coordinate based on the latitude, longitude
and zoom level
Returns: An X,Y tile coordinate
"""
tile_size = 256
# Use a left shift to get the power of 2
# i.e. a zoom level of 2 will have 2^2 = 4 tiles
numTiles = 1 << self._zoom
# Find the x_point given the longitude
point_x = (tile_size/ 2 + self._lng * tile_size / 360.0) * numTiles // tile_size
# Convert the latitude to radians and take the sine
sin_y = math.sin(self._lat * (math.pi / 180.0))
# Calulate the y coorindate
point_y = ((tile_size / 2) + 0.5 * math.log((1+sin_y)/(1-sin_y)) * -(tile_size / (2 * math.pi))) * numTiles // tile_size
return int(point_x), int(point_y)
def generateImage(self, **kwargs):
"""
Generates an image by stitching a number of google map tiles together.
Args:
start_x: The top-left x-tile coordinate
start_y: The top-left y-tile coordinate
tile_width: The number of tiles wide the image should be -
defaults to 5
tile_height: The number of tiles high the image should be -
defaults to 5
Returns:
A high-resolution Goole Map image.
"""
start_x = kwargs.get('start_x', None)
start_y = kwargs.get('start_y', None)
tile_width = kwargs.get('tile_width', 5)
tile_height = kwargs.get('tile_height', 5)
# Check that we have x and y tile coordinates
if start_x == None or start_y == None :
start_x, start_y = self.getXY()
# Determine the size of the image
width, height = 256 * tile_width, 256 * tile_height
#Create a new image of the size require
map_img = Image.new('RGB', (width,height))
for x in range(0, tile_width):
for y in range(0, tile_height) :
url = 'https://mt0.google.com/vt?x='+str(start_x+x)+'&y='+str(start_y+y)+'&z='+str(self._zoom)
current_tile = str(x)+'-'+str(y)
urllib.urlretrieve(url, current_tile)
im = Image.open(current_tile)
map_img.paste(im, (x*256, y*256))
os.remove(current_tile)
return map_img
def main():
# Create a new instance of GoogleMap Downloader
gmd = GoogleMapDownloader(51.5171, 0.1062, 13)
print("The tile coorindates are {}".format(gmd.getXY()))
try:
# Get the high resolution image
img = gmd.generateImage()
except IOError:
print("Could not generate the image - try adjusting the zoom level and checking your coordinates")
else:
#Save the image to disk
img.save("high_resolution_image.png")
print("The map has successfully been created")
if __name__ == '__main__': main()
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