php – 读取文件的元数据

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虽然我自己没有使用过这个,但是在sourceforge上的XMP PHP工具包听起来就像你可能正在寻找的那样： http://xmpphptoolkit.sourceforge.net/据说 – 它是alpha版本,并且在一年多的时间里没有更新.

XMP Toolkit PHP Extension is a PHP module which includes the Adobe XMP
Toolkit SDK. This PHP5 extension will provide classes and methods to
manipulate XMP Metadatas from files like jpegs,tiff,png,but also
wav,mp3,avi,mpeg4,pdf,ai,eps… It’s based from the Adobe XMP
Toolkit SDK 4.4.2. The goal of this extension is to have php classes
which can open files,extract metadatas,manipulate them,and put them
back within few lines of php code. This project is under GPL v3
License.

您还可以使用iptcembed将任意元数据写入图像文件.正如您在评论中提到的,这仅适用于JPEG文件.

http://php.net/manual/en/function.iptcembed.php

这是一个来自类的注释的脚本,它将获取和设置IPTC数据：

<?

    /************************************************************

        IPTC EASY 1.0 - IPTC data manipulator for JPEG images

        All reserved www.image-host-script.com

        Sep 15,2008

    ************************************************************/

    DEFINE('IPTC_OBJECT_NAME','005');
    DEFINE('IPTC_EDIT_STATUS','007');
    DEFINE('IPTC_PRIORITY','010');
    DEFINE('IPTC_CATEGORY','015');
    DEFINE('IPTC_SUPPLEMENTAL_CATEGORY','020');
    DEFINE('IPTC_FIXTURE_IDENTIFIER','022');
    DEFINE('IPTC_KEYWORDS','025');
    DEFINE('IPTC_RELEASE_DATE','030');
    DEFINE('IPTC_RELEASE_TIME','035');
    DEFINE('IPTC_SPECIAL_INSTRUCTIONS','040');
    DEFINE('IPTC_REFERENCE_SERVICE','045');
    DEFINE('IPTC_REFERENCE_DATE','047');
    DEFINE('IPTC_REFERENCE_NUMBER','050');
    DEFINE('IPTC_CREATED_DATE','055');
    DEFINE('IPTC_CREATED_TIME','060');
    DEFINE('IPTC_ORIGINATING_PROGRAM','065');
    DEFINE('IPTC_PROGRAM_VERSION','070');
    DEFINE('IPTC_OBJECT_CYCLE','075');
    DEFINE('IPTC_BYLINE','080');
    DEFINE('IPTC_BYLINE_TITLE','085');
    DEFINE('IPTC_CITY','090');
    DEFINE('IPTC_PROVINCE_STATE','095');
    DEFINE('IPTC_COUNTRY_CODE','100');
    DEFINE('IPTC_COUNTRY','101');
    DEFINE('IPTC_ORIGINAL_TRANSMISSION_REFERENCE','103');
    DEFINE('IPTC_HEADLINE','105');
    DEFINE('IPTC_CREDIT','110');
    DEFINE('IPTC_SOURCE','115');
    DEFINE('IPTC_COPYRIGHT_STRING','116');
    DEFINE('IPTC_CAPTION','120');
    DEFINE('IPTC_LOCAL_CAPTION','121');

    class iptc {
        var $meta=Array();
        var $hasmeta=false;
        var $file=false;


        function iptc($filename) {
            $size = getimagesize($filename,$info);
            $this->hasmeta = isset($info["APP13"]);
            if($this->hasmeta)
                $this->meta = iptcparse ($info["APP13"]);
            $this->file = $filename;
        }
        function set($tag,$data) {
            $this->meta ["2#$tag"]= Array( $data );
            $this->hasmeta=true;
        }
        function get($tag) {
            return isset($this->meta["2#$tag"]) ? $this->meta["2#$tag"][0] : false;
        }

        function dump() {
            print_r($this->meta);
        }
        function binary() {
            $iptc_new = '';
            foreach (array_keys($this->meta) as $s) {
                $tag = str_replace("2#","",$s);
                $iptc_new .= $this->iptc_maketag(2,$tag,$this->meta[$s][0]);
            }        
            return $iptc_new;    
        }
        function iptc_maketag($rec,$dat,$val) {
            $len = strlen($val);
            if ($len < 0x8000) {
                   return chr(0x1c).chr($rec).chr($dat).
                   chr($len >> 8).
                   chr($len & 0xff).
                   $val;
            } else {
                   return chr(0x1c).chr($rec).chr($dat).
                   chr(0x80).chr(0x04).
                   chr(($len >> 24) & 0xff).
                   chr(($len >> 16) & 0xff).
                   chr(($len >> 8 ) & 0xff).
                   chr(($len ) & 0xff).
                   $val;

            }
        }    
        function write() {
            if(!function_exists('iptcembed')) return false;
            $mode = 0;
            $content = iptcembed($this->binary(),$this->file,$mode);    
            $filename = $this->file;

            @unlink($filename); #delete if exists

            $fp = fopen($filename,"w");
            fwrite($fp,$content);
            fclose($fp);
        }    

        #requires GD library installed
        function removeAllTags() {
            $this->hasmeta=false;
            $this->meta=Array();
            $img = imagecreatefromstring(implode(file($this->file)));
            @unlink($this->file); #delete if exists
            imagejpeg($img,100);
        }
    };


?>

示例读取版权字符串：

$i = new iptc("test.jpg");
echo $i->get(IPTC_COPYRIGHT_STRING);

更新版权声明：

$i = new iptc("test.jpg");
echo $i->set(IPTC_COPYRIGHT_STRING,"Here goes the new data"); 
$i->write();