使用python下載地圖切片非常方便，只需要知道切片的url規則，就可以將所有地圖切片爬取下來。本文使用的python版本為3.6.

　　谷歌地圖衛星影像切片url如下：

　　　　http://www.google.cn/maps/[email protected]&gl=cn&x=107&y=49&z=7

　　我們只需要根據經緯度計算出行列號，帶入url中的xy即可，z代表zoom值。程式碼如下：

from urllib import request
import re
import urllib.request
import os
import random
import math

agents = [
    'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.101 Safari/537.36',
    'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.0.249.0 Safari/532.5',
    'Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US) AppleWebKit/532.9 (KHTML, like Gecko) Chrome/5.0.310.0 Safari/532.9',
    'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/534.7 (KHTML, like Gecko) Chrome/7.0.514.0 Safari/534.7',
    'Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/534.14 (KHTML, like Gecko) Chrome/9.0.601.0 Safari/534.14',
    'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.14 (KHTML, like Gecko) Chrome/10.0.601.0 Safari/534.14',
    'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.20 (KHTML, like Gecko) Chrome/11.0.672.2 Safari/534.20", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.27 (KHTML, like Gecko) Chrome/12.0.712.0 Safari/534.27',
    'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.24 Safari/535.1']


# 經緯度反算切片行列號 3857座標系
def deg2num(lat_deg, lon_deg, zoom):
    lat_rad = math.radians(lat_deg)
    n = 2.0 ** zoom
    xtile = int((lon_deg + 180.0) / 360.0 * n)
    ytile = int((1.0 - math.log(math.tan(lat_rad) + (1 / math.cos(lat_rad))) / math.pi) / 2.0 * n)
    return (xtile, ytile)


# 下載圖片
def getimg(Tpath, Spath, x, y):
    try:
        f = open(Spath, 'wb')
        req = urllib.request.Request(Tpath)
        req.add_header('User-Agent', random.choice(agents))  # 換用隨機的請求頭
        pic = urllib.request.urlopen(req, timeout=60)

        f.write(pic.read())
        f.close()
        print(str(x) + '_' + str(y) + '下載成功')
    except Exception:
        print(str(x) + '_' + str(y) + '下載失敗,重試')
        getimg(Tpath, Spath, x, y)


path = r"E:\天地圖切片"
if not os.path.exists(path):
    os.mkdir(path)

zoom = 15  # 下載切片的zoom
lefttop = deg2num(36.022968, 120.064056, zoom)  # 下載切片的左上角角點
rightbottom = deg2num(35.894891, 120.344615, zoom)

print(str(lefttop[0]))
print(str(rightbottom[0]))
print(str(lefttop[1]))
print(str(rightbottom[1]))
print("共" + str(lefttop[0] - rightbottom[0]))
print("共" + str(lefttop[1] - rightbottom[1]))

for x in range(lefttop[0], rightbottom[0]):
    for y in range(lefttop[1], rightbottom[1]):
        tilepath = "http://t3.tianditu.gov.cn/DataServer?T=cva_w&x=" + str(x) + "&y=" + str(y) + "&l=" + str(zoom)
        # 天地圖的url 可以換成谷歌地圖的
        getimg(tilepath, os.path.join(path, str(x) + "_" + str(y) + ".png"), x, y)
print('完成')