$rawExif = exif_read_data($imgName);
    if( isset($rawExif['GPSLatitude']) )
    {
      eval('$degree = $rawExif["GPSLatitude"][0];');
      eval('$mins   = $rawExif["GPSLatitude"][1];');
      eval('$secs   = $rawExif["GPSLatitude"][2];');
      $lat = $degree + ( $mins / 60 ) + ( $secs / 3600 ); 
      if( $rawExif['GPSLatitudeRef'] == 'S' )
      {
        $lat = (-1) * $lat;
      }

      eval('$degree = $rawExif["GPSLongitude"][0];');
      eval('$mins   = $rawExif["GPSLongitude"][1];');
      eval('$secs   = $rawExif["GPSLongitude"][2];');
      $lng = $degree + ( $mins / 60 ) + ( $secs / 3600 ); 
      if( $rawExif['GPSLongitudeRef'] == 'W' )
      {
        $lng = (-1) * $lng;
      }
      
      echo "$lat, $lng";
    }

 

อ้างอิง: http://andrew.hedges.name/experiments/convert_lat_long/