merge_tiles.py

from PIL import Image
import sys, os
from gmap_utils import *

def mergeTiles(source, zoom, (lat_start, lat_stop, lon_start, lon_stop)):
    if len(source)!=1:
        print '-- unknown external source'
        return
    key  = source.keys()[0]
    ext  = source[key]
    TYPE = ext['type']
    EXT  = ext['ext']
    x_start, y_start = latlon2xy(zoom, lat_start, lon_start)
    x_stop, y_stop = latlon2xy(zoom, lat_stop, lon_stop)
    print "x range", x_start, x_stop
    print "y range", y_start, y_stop
    w = (x_stop - x_start) * 256
    h = (y_stop - y_start) * 256
    print "width:", w
    print "height:", h
    result = Image.new("RGBA", (w, h))
    for x in xrange(x_start, x_stop):
        for y in xrange(y_start, y_stop):
            filename = "%s_%s_%d_%d_%d.%s" % (key, TYPE, zoom, x, y, EXT)
            if not os.path.exists(filename):
                print "-- missing", filename
                continue
            x_paste = (x - x_start) * 256
            y_paste = h - (y_stop - y) * 256
            try:
                i = Image.open(filename)
            except Exception, e:
                print "-- %s, removing %s" % (e, filename)
                #trash_dst = os.path.expanduser("~/.Trash/%s" % filename)
                #os.rename(filename, trash_dst)
                os.remove(filename)
                continue
            result.paste(i, (x_paste, y_paste))
            del i
    output_filename = "map_%s_%s_%d.%s" % (key, TYPE, zoom, EXT)
    result.save(output_filename)
    return output_filename


def main():
    from sources import searchSource
    found_sources = searchSource('sources.json',search={'type':'sat'})
    key = found_sources.keys()[0]
    source = {key: found_sources[key]}
    zoom = 10
    lat_start, lon_start = 36.99, -114.03
    lat_stop, lon_stop = 35.64, -111.60
    mergeTiles(source, zoom, (lat_start, lat_stop, lon_start, lon_stop))


if __name__ == '__main__':
    main()