Trasparenza immagine png/gif in form di resize

[Marcolino92]

Salve, in questo codice che permette il resize delle immagini vorrei preservare la trasparenza per le immagini png e gif caricate che invece vengono mostrate con sfondo nero.

error_reporting(0);

$change="";
$abc="";




 define ("MAX_SIZE","500");
 function getExtension($str) {
         $i = strrpos($str,".");
         if (!$i) { return ""; }
         $l = strlen($str) - $i;
         $ext = substr($str,$i+1,$l);
         return $ext;
 }


 $errors=0;
  
 if($_SERVER["REQUEST_METHOD"] == "POST")
 {
     $image =$_FILES["file"]["name"];
    $uploadedfile = $_FILES['file']['tmp_name'];


     if ($image) 
     {
     
         $filename = stripslashes($_FILES['file']['name']);
     
          $extension = getExtension($filename);
         $extension = strtolower($extension);
        
        
 if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png") && ($extension != "gif")) 
         {
        
             $change='<div class="msgdiv">Unknown Image extension </div> ';
             $errors=1;
         }
         else
         {


 $size=filesize($_FILES['file']['tmp_name']);




if ($size > MAX_SIZE*1024)
{
    $change='<div class="msgdiv">You have exceeded the size limit!</div> ';
    $errors=1;
}




if($extension=="jpg" || $extension=="jpeg" )
{
$uploadedfile = $_FILES['file']['tmp_name'];
$src = imagecreatefromjpeg($uploadedfile);


}
else if($extension=="png")
{
$uploadedfile = $_FILES['file']['tmp_name'];
$src = imagecreatefrompng($uploadedfile);


}
else 
{
$src = imagecreatefromgif($uploadedfile);
}


echo $scr;


list($width,$height)=getimagesize($uploadedfile);




$newwidth=60;
$newheight=($height/$width)*$newwidth;
$tmp=imagecreatetruecolor($newwidth,$newheight);


$newwidth1=128;
$newheight1=($height/$width)*$newwidth1;
$tmp1=imagecreatetruecolor($newwidth1,$newheight1);


$newwidth2=100;
$newheight2=($height/$width)*$newwidth2;
$tmp2=imagecreatetruecolor($newwidth2,$newheight2);


$newwidth3=80;
$newheight3=($height/$width)*$newwidth3;
$tmp3=imagecreatetruecolor($newwidth3,$newheight3);


imagecopyresampled($tmp,$src,0,0,0,0,$newwidth,$newheight,$width,$height);


imagecopyresampled($tmp1,$src,0,0,0,0,$newwidth1,$newheight1,$width,$height);


imagecopyresampled($tmp2,$src,0,0,0,0,$newwidth2,$newheight2,$width,$height);


imagecopyresampled($tmp3,$src,0,0,0,0,$newwidth3,$newheight3,$width,$height);


$filename = "images/". $_FILES['file']['name'];


$filename1 = "images/small/". $_FILES['file']['name'];


$filename2 = "images/100/". $_FILES['file']['name'];


$filename3 = "images/80/". $_FILES['file']['name'];






imagejpeg($tmp,$filename,100);


imagejpeg($tmp1,$filename1,100);


imagejpeg($tmp2,$filename2,100);


imagejpeg($tmp3,$filename3,100);


imagedestroy($src);
imagedestroy($tmp);
imagedestroy($tmp1);
imagedestroy($tmp2);
imagedestroy($tmp3);
}}


}


//If no errors registred, print the success message
 if(isset($_POST['Submit']) && !$errors) 
 {
 
   // mysql_query("update {$prefix}users set img='$big',img_small='$small' where user_id='$user'");
     $change='<div>Image Uploaded Successfully!</div>';  }

Grazie

[Alhazred]

Basta cercare, questo è il primo link che ho trovato digitando "php png transparent black"
http://stackoverflow.com/questions/2...of-transparent

ma ne trovi tanti altri

[Marcolino92]

Ciao, grazie per la risposta. Avevo gia trovato questi risultati, ma non sono riuscito ad applicarli nel mio caso, per questo motivo avrei bisogno di aiuto piu dettagliato, nel senso, indicarmi quale pezzo sostituire o aggiungere nel mio codice.