天地图切片下载优化方案 ez_tdt_title_download.py

from ez_title_index import lng_lat_to_title_index import requests

Pillow

from PIL import Image import os

文件存放位置设置

BASE_PATH = os.path.join(os.path.abspath(os.curdir), 'disc') BASE_PATH_res = os.path.join(os.path.abspath(os.curdir), 'result')

简单反爬虫 , 可以不写

headers = { "Connection": "keep-alive", "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36", }

下载瓦片

def download_pic(x, y, z): """ 下载地图 :param x: x 范围 :param y: y 范围 :param z: int """ try:

下载图片

    key = 'a4ee5c551598a1889adfabff55a5fc27'
    for xi in x:
        xpathlayer = os.path.join(BASE_PATH, str(z))#地图层目录
        if (os.path.exists(xpathlayer) == False):
            os.mkdir(xpathlayer)
        xpath = os.path.join(xpathlayer, str(xi))#地图X坐标目录
        if(os.path.exists(xpath)==False):
            os.mkdir(xpath)

        for yi in y:
            #url = "http://t2.tianditu.gov.cn/DataServer?T=img_w&x={}&y={}&l={}&tk={}".format(xi, yi, z, key)
            url = "http://t3.tianditu.gov.cn/DataServer?T=img_w&x={}&y={}&l={}&tk={}".format(xi, yi, z, key)
            # 保存文件名称
            fileName = os.path.join(xpath, "{}.png".format(yi))
            # 具体下载操作
            if (os.path.exists(fileName)) == False:
                r = requests.get(url=url, headers=headers)
                if r.status_code == 200:
                    with open(fileName, 'wb') as f:
                        for chunk in r:
                            f.write(chunk)
                else:
                    print("访问异常")
except Exception as e:
    print(e)
    pass

合并瓦片

def merge_pic(x, y, z): """ 合并下载地图 :param x: x 范围 :param y: y 范围 :param z: int :return: """ picSize = 256 try:

构造平图矩阵

    li = []

    for xi in x:
        xpathlayer = os.path.join(BASE_PATH, str(z))  # 地图层目录
        xpath = os.path.join(xpathlayer, str(xi))  # 地图X坐标目录
        lis = []
        for yi in y:
            fileName = os.path.join(xpath, "{}.png".format(yi))
            lis.append(fileName)

        li.append(lis)

    oca = len(x)
    ocb = len(y)

    toImage = Image.new('RGBA', (oca * picSize, ocb * picSize))

    for i in range(oca):
        for j in range(ocb):
            fromImge = Image.open(li[i][j])
            picx = 256 * i
            picy = 256 * j
            loc = (picx, picy)
            toImage.paste(fromImge, loc)

    toImage.save(os.path.join(BASE_PATH_res, "rs{}.png".format(z)))
    print("构造完成输出图片")

except Exception as e:
    print(e)
    pass

def run_spider(z, minx, maxx, miny, maxy): """ 下载切片地图 :param z:放大级别 :param minx: 最小x :param maxx: 最大x :param miny: 最小y :param maxy: 最大y :return: """

z = 18

xy = [minx, miny]#左下角 经纬度坐标
xxyy = [maxx, maxy]#右上角 经纬度坐标

minxy = lng_lat_to_title_index(xy[0], xy[1], z) #转换后的瓦片坐标
maxxy = lng_lat_to_title_index(xxyy[0], xxyy[1], z) #转换后的瓦片坐标
xr = range(minxy[0], maxxy[0]+1)
yr = range( maxxy[1],minxy[1]+1)
download_pic(xr, yr, z)#下载瓦片
merge_pic(xr, yr, z)#合并瓦片成为大图

if name == 'main': run_spider(z=15, minx=121.315498352051, maxx=121.338307857513, miny=30.6949805750931, maxy=30.7056264386052)

huifer / tianditu-python

分目录下载瓦片，可以直接用openlayer加载 #7