How to get bounds of a google static map?

Question

How to get bounds in degrees of google static map which has been returned, for example, for following request

http://maps.googleapis.com/maps/api/staticmap?c         


        

Answer 1

For big zoom factors (>=8), where non-uniformity of map scale on y axis can be neglected, there is much easier method, where we just takes into accout 1/cos(latitude) correction for pixels/(degrees of latitude) resolution. Initial resolution for zoom=0 is 256 pixels per 360 degrees both for x and y at 0 lattitude.

def get_static_map_bounds(lat, lng, zoom, sx, sy):
    # lat, lng - center
    # sx, sy - map size in pixels

    # 256 pixels - initial map size for zoom factor 0
    sz = 256 * 2 ** zoom

    #resolution in degrees per pixel
    res_lat = cos(lat * pi / 180.) * 360. / sz
    res_lng = 360./sz

    d_lat = res_lat * sy / 2
    d_lng = res_lng * sx / 2

    return ((lat-d_lat, lng-d_lng), (lat+d_lat, lng+d_lng))