Bombsquad.Exif.ExifGpsInfoParser.ParseAltitude C# (CSharp) Method

        private static double? ParseAltitude( BitmapMetadata metadata )
        {
            var altitude = metadata.ReadUnsignedRational( AltitudeQuery );
            if( ! altitude.HasValue )
            {
                return null;
            }

            var altitudeReference = metadata.ReadByte( AltitudeReferenceQuery );
            if( altitudeReference.HasValue && altitudeReference.Value == 1 )
            {
                altitude = -altitude;
            }
            return altitude;
        }