Python: get GPS latitude and longitude coordinates from JPEG EXIF using exifread

exif_gps.py

import exifread

# based on https://gist.github.com/erans/983821

def _get_if_exist(data, key):
    if key in data:
        return data[key]

    return None


def _convert_to_degress(value):
    """
    Helper function to convert the GPS coordinates stored in the EXIF to degress in float format

    :param value:
    :type value: exifread.utils.Ratio
    :rtype: float
    """
    d = float(value.values[0].num) / float(value.values[0].den)
    m = float(value.values[1].num) / float(value.values[1].den)
    s = float(value.values[2].num) / float(value.values[2].den)

    return d + (m / 60.0) + (s / 3600.0)
    
def get_exif_location(exif_data):
    """
    Returns the latitude and longitude, if available, from the provided exif_data (obtained through get_exif_data above)
    """
    lat = None
    lon = None

    gps_latitude = _get_if_exist(exif_data, 'GPS GPSLatitude')
    gps_latitude_ref = _get_if_exist(exif_data, 'GPS GPSLatitudeRef')
    gps_longitude = _get_if_exist(exif_data, 'GPS GPSLongitude')
    gps_longitude_ref = _get_if_exist(exif_data, 'GPS GPSLongitudeRef')

    if gps_latitude and gps_latitude_ref and gps_longitude and gps_longitude_ref:
        lat = _convert_to_degress(gps_latitude)
        if gps_latitude_ref.values[0] != 'N':
            lat = 0 - lat

        lon = _convert_to_degress(gps_longitude)
        if gps_longitude_ref.values[0] != 'E':
            lon = 0 - lon

    return lat, lon

very helpful code

Thanks for this! I cant seem to actually return or print the coordinates to terminal, how can I do that?

There is no get_exif_data in this gist.

@ryanmeasel

def get_exif_data(image_file):
    with open(image_file, 'rb') as f:
        exif_tags = exifread.process_file(f)
    return exif_tags 

lat, long = get_exif_location(get_exif_data(image_file))

I also added altitude:

gps_altitude_ref = _get_if_exist(exif_data, 'GPS GPSAltitudeRef')
gps_altitude = _get_if_exist(exif_data, 'GPS GPSAltitude')

if gps_altitude and gps_altitude_ref:
     alt = gps_altitude.values[0]
     altitude = alt.num / alt.den
     if gps_altitude_ref.values[0] == 1: altitude *= -1

return lat, lon, altitude

Thanks for code!

Some improvements

1. More accuracy with Decimal calculations (instead of float)

from decimal import Decimal

d, m, s = coord_value
decimal_degrees = (
    Decimal(d.numerator) / Decimal(d.denominator)
    + Decimal(m.numerator) / Decimal(m.denominator) / Decimal(60)
    + Decimal(s.numerator) / Decimal(s.denominator) / Decimal(3600)
)

2. Shorter ref usage

if coord_ref in {"S", "W"}:
    decimal_degrees *= -1

3. Shorter result

#  GoogleMaps ngigits=7, but 6 == 0.1 meter distance - a lot :)
return round(float(decimal_degrees), ndigits=7)

Sorry for var naming, got it from my solution, based on Pillow
https://gitlab.com/-/snippets/2215069

@Olegt0rr one question - do we really need to use Decimals if we do not care about precision less than 10e6?

@snakeye just in case )))

Great, this script solved my issue. Thanks for sharing!