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我到处搜索过，但找不到解决方案，所以我决定在PHP中编写我自己的类。一些我用iPhone图像文件和instagram图像取得成功，但我不确定它是否适用于所有其他相机，尤其是支持Android的手机和带GPS的相机。任何人都可以帮我解决这个问题吗？以下是我的代码及其实现。如何从图像文件获取地理位置（坐标）？
<?php
class Filer {
/**
* Some Variables
*/
private $_gpsLatitude;
private $_gpsLongitude;
private $_gpsLatitudeRef;
private $_gpsLongitudeRef;
/**
* Constructor Method
*/
public function __construct(){
/**
* GPS Meta (In reference to iphone's image file)
* May be Android folow the same thing (Haven't checked)
*/
$this->_gpsLatitude = 'GPSLatitude';
$this->_gpsLongitude = 'GPSLongitude';
$this->_GPSLongitudeRef = 'GPSLatitudeRef';
$this->_gpsLongitudeRef = 'GPSLongitudeRef';
}
/**
* Check if the file contains GPS information
* @param: (string)$_file
* @return: (array) File's EXIF data (If the file contains GPS information)
*/
public function getCoordinate($_file){
$_Metas = $this->checkGPS($_file);
$_GPS = $_Metas['GPS'];
$_latitude = $this->DMStoDEC(
$_GPS[$this->_gpsLatitude][0],
$_GPS[$this->_gpsLatitude][1],
$_GPS[$this->_gpsLatitude][2],
$_GPS[$this->_GPSLongitudeRef]
);
$_longitude = $this->DMStoDEC(
$_GPS[$this->_gpsLongitude][0],
$_GPS[$this->_gpsLongitude][1],
$_GPS[$this->_gpsLongitude][2],
$_GPS[$this->_gpsLongitudeRef]
);
$_location = array($_latitude, $_longitude);
return $_location;
}
/**
* Check if the file contains GPS information
* @param: (string)$_file
* @return: (array) File's EXIF data (If the file contains GPS information)
*/
public function checkGPS($_file){
return exif_read_data($_file, 'GPS', true);
}
/**
* Get Meta information of file
* @param: (string)$_file
* @return: (array) File's EXIF data
*
*/
public function getExif($_file){
return exif_read_data($_file, 'IFD0', true);
}
/**
* Converts DMS (Degrees/Minutes/Seconds)
* To decimal format longitude/latitude
* @param: (string)$_deg, (string)$_min, (string)$_sec, (string)$_ref
* @return: (float)
*/
private function DMStoDEC($_deg, $_min, $_sec, $_ref){
$_array = explode('/', $_deg);
$_deg = $_array[0]/$_array[1];
$_array = explode('/', $_min);
$_min = $_array[0]/$_array[1];
$_array = explode('/', $_sec);
$_sec = $_array[0]/$_array[1];
$_coordinate = $_deg+((($_min*60)+($_sec))/3600);
/**
* + + = North/East
* + - = North/West
* - - = South/West
* - + = South/East
*/
if('s' === strtolower($_ref) || 'w' === strtolower($_ref)){
// Negatify the coordinate
$_coordinate = 0-$_coordinate;
}
return $_coordinate;
}
/**
*
* Converts decimal longitude/latitude to DMS
* (Degrees/minutes/seconds)
*
* This is the piece of code which may appear to
* be inefficient, but to avoid issues with floating
* point math we extract the integer part and the float
* part by using a string function.
* @param: (string)$_file
* @return: (array)
*/
private function DECtoDMS($_dec){
$_vars = explode(".", $_dec);
$_deg = $vars[0];
$_tempma = "0.".$_vars[1];
$_tempma = $_tempma * 3600;
$_min = floor($_tempma/60);
$_sec = $_tempma - ($_min*60);
return array("deg"=>$_deg, "min"=>$_min, "sec"=>$_sec);
}
} // End class
/**
*
* Usage Example
*
*/
$_file = './image2.jpg';
$_Filer = new Filer();
if($_Filer->checkGPS($_file)){
$_location = $_Filer->getCoordinate($_file);
// File doesn't have GPS information
echo '<h4>File\'s GPS information</h4>';
var_dump($_location);
} else {
// File doesn't have GPS information
echo '<h4>Sorry your file doesn\'t supply GPS information</h4>';
var_dump($_Filer->getExif($_file));
}
?>