himawari8downloader.py

import sys
import json
import requests
from PIL import Image
from io import BytesIO
from datetime import datetime
from dateutil import tz

conf ={
    'last_refresh_url': 'http://himawari8-dl.nict.go.jp/himawari8/img/D531106/latest.json',  # latest photo
    'img_url_pattern': 'http://himawari8-dl.nict.go.jp/himawari8/img/D531106/%id/550/%s_%i_%i.png',    # scale, time, row, col
    'scale': 1,     # 1, 2, 4, 8, 16, 20.  Width and height are both 550*scale
}


# Convert time
def utf2local(utc):
    from_zone = tz.tzutc()
    to_zone = tz.tzlocal()
    utc = utc.replace(tzinfo=from_zone)
    return utc.astimezone(to_zone)


def download(args):
    scale = args['scale']
    png = Image.new('RGB', (550*scale, 550*scale))
    for row in range(scale):
        for col in range(scale):
            print 'Downloading %i of %i ...' % (row*scale + col + 1, scale*scale)
            strtime = args['time'].strftime("%Y/%m/%d/%H%M%S")
            url = conf['img_url_pattern'] % (args['scale'], strtime, row, col)
            r = requests.get(url)
            tile = Image.open(BytesIO(r.content))
            png.paste(tile, (550 * row, 550 * col, 550 * (row + 1), 550 * (col + 1)))
    if 'fout' in args:
        fpath = args['fout']
    else:
        fpath = "%s.png" % utf2local(args['time']).strftime("%Y/%m/%d/%H%M%S").replace('/', '')
    print 'Download over, save to file %s' % fpath
    png.save(fpath, "PNG")


def get_last_time():
    r = requests.get(conf['last_refresh_url'])
    resp = json.loads(r.text)
    last_refresh_time = datetime.strptime(resp['date'], '%Y-%m-%d %H:%M:%S')
    return last_refresh_time


def get_last_image(fout=None, scale=1):
    print 'output[%s] scale[%i]' %(fout, scale)
    last_refresh_time = get_last_time()
    args = {'time': last_refresh_time}
    args['scale'] = scale
    if fout is not None:
        args['fout'] = fout
    download(args)


if __name__ == '__main__':
    if len(sys.argv) == 1:
        get_last_image()
    elif len(sys.argv) == 2:
        get_last_image(fout=sys.argv[1])
    elif len(sys.argv) == 3:
        get_last_image(fout=sys.argv[1], scale=int(sys.argv[2]))