✔ .jpg download via Header

 	header("Content-Type: application/octet-stream");
 	header("Content-Disposition: attachment; filename=$file");
 	header("Content-Length: ".filesize($ordner.$file)); 
 	header("Pragma: no-cache");
 	header("Expires: 0"); 
 	readfile($ordner.$file);

<?php
$mimetypes = array(      
'bmp'        => 'image/bmp',      
'gif'        => 'image/gif',      
'ief'        => 'image/ief',     
 'jpeg'        => 'image/jpeg',      
'jpg'        => 'image/jpeg',      
'jpe'        => 'image/jpeg',     
 'png'        => 'image/png'  );    

$imgID = $_GET['ID'];    

$picdownq = mysql_query("SELECT id, uid, bildname, format, savename, public FROM tblbilder WHERE savename = '" . $imgID . "'") or die("Kann diese Datei nicht finden!");
$picdownr = mysql_fetch_assoc($picdownq);    

$basedir = "pixis/" . $picdownr['uid'] . "/";    

$filename = $picdownr['savename'] . "." . $picdownr['format'];  

$file = $basedir . $filename;    

$name = $picdownr['bildname'] . "." . $picdownr['format'];    

header("Content-type: " . $mimetypes[$picdownr['format']]);  
header("Content-Length: " . filesize($file));  
header("Content-Disposition: attachment; filename=" . $name);  

readfile($file);  
?>

 <?php
 $file = $_GET["f"];
 if (is_file($file)) {
 	//info über file sammeln
 	$len = filesize($file);
 	$filename = basename($file);
 	$file_extension = strtolower(substr(strrchr($filename, "."), 1));
 
 	//content type entsprechend der ext definieren
 	switch($file_extension) {
 		case "pdf": $ctype="application/pdf"; break;
 		case "exe": $ctype="application/octet-stream"; break;
 		case "zip": $ctype="application/zip"; break;
 		case "doc": $ctype="application/msword"; break;
 		case "xls": $ctype="application/vnd.ms-excel"; break;
 		case "ppt": $ctype="application/vnd.ms-powerpoint"; break;
 		case "gif": $ctype="image/gif"; break;
 		case "png": $ctype="image/png"; break;
 		case "jpeg":
 		case "jpg": $ctype="image/jpg"; break;
 		case "mp3": $ctype="audio/mpeg"; break;
 		case "wav": $ctype="audio/x-wav"; break;
 		case "mpeg":
 		case "mpg":
 		case "mpe": $ctype="video/mpeg"; break;
 		case "mov": $ctype="video/quicktime"; break;
 		case "avi": $ctype="video/x-msvideo"; break;
 
 		//folgendes ist für dateien die nicht downgeloadet werden dürfen
 		case "inc":
 		case "sql":
 		case "asp":
 		case "cgi":
 		case "htaccess":
 		case "php":
 		case "php3":
 		case "php4": exit;
 		
 		default: $ctype="application/force-download";
 	}
 
 	//header beginn
 	header("Pragma: public");
 	header("Expires: 0");
 	header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
 	header("Cache-Control: public");
 	header("Content-Description: File Transfer");
 	
 	//den switch-erstellten ctype verwenden
 	header("Content-Type: $ctype");
 
 	//download starten
 	$header="Content-Disposition: attachment; filename=".$filename.";";
 	header($header);
 	header("Content-Transfer-Encoding: binary");
 	header("Content-Length: ".$len);
 	@readfile($file);
 	exit;
 } else {
 	exit;
 }
 ?>