ciao, sto facendo prove in locale per caricare delle immagini, nello specifico per convertire l'estensione (qualunque) in jpg, ma riscontro svariati problemi. Se l'immagine è jpg tutto è ok, se si tratta di gif o png ricevo questi warning:

codice:
Warning: imagecopyresampled(): supplied argument is not a valid Image resource in C:\Programmi\Apache Software Foundation\Apache2.2\htdocs\prova\capitolo7\check_image.php on line 44

Warning: imagedestroy(): supplied argument is not a valid Image resource in C:\Programmi\Apache Software Foundation\Apache2.2\htdocs\prova\capitolo7\check_image.php on line 46

Warning: Cannot modify header information - headers already sent by (output started at C:\Programmi\Apache Software Foundation\Apache2.2\htdocs\prova\capitolo7\check_image.php:44) in C:\Programmi\Apache Software Foundation\Apache2.2\htdocs\prova\capitolo7\check_image.php on line 50

Warning: rename(C:/Programmi/Apache Software Foundation/Apache2.2/htdocs/prova/images/immagine.gif,C:/Programmi/Apache Software Foundation/Apache2.2/htdocs/prova/images/21.jpg) [function.rename]: File exists in C:\Programmi\Apache Software Foundation\Apache2.2\htdocs\prova\capitolo7\check_image.php on line 53
il che mi fa capire che il codice di conversione non si comporta correttamente, ma non riesco a decifrare bene i warning.
questo il codice:
Codice PHP:
$image_caption =$_POST['image_caption'];
$image_username $_POST['image_username'];
$image_tempname $_FILES['image_filename'] ['name'];
$today date("Y-m-d");

$ImageDir ="C:/Programmi/Apache Software Foundation/Apache2.2/htdocs/prova/images/";
$ImageName $ImageDir $image_tempname;

if (
move_uploaded_file($_FILES['image_filename']['tmp_name'],$ImageName)) {
    list(
$width$height$type$attr) = getimagesize($ImageName);
    
if (
$type 3) {
    echo 
"Sorry, but the file you uploaded was not a GIF, JPG, or PNG file.
"
;
    echo 
"Please hit your browser's 'back' button and try again.";
} else {
        
        
$insert "INSERT INTO images
                    (image_caption, image_username, image_date)
                    VALUES
                    ('
$image_caption', '$image_username', '$today')";
        
$insertresults mysql_query($insert)
            or die(
mysql_error());
        
        
$lastpicid mysql_insert_id();
        
        
$newfilename $ImageDir $lastpicid ".jpg";
        
        if (
$type == 2) {
            
rename($ImageName$newfilename);
        } else {
            if (
type == 1) {
                
$image_old imagecreatefromgif($ImageName);
            } elseif (
$type == 3) {
                
$image_old imagecreatefrompng($ImageName);
            }
            
            
$image_jpg imagecreatetruecolor($width$height);
                
imagecopyresampled($image_jpg$image_old0000$width$height$width$height);
                
imagejpeg($image_jpg$newfilename);
                
imagedestroy($image_old);
                
imagedestroy($image_jpg);
            }
            
$url "location: showimage.php?id=" $lastpicid;
            
header($url);
        }
        
        
rename($ImageName$newfilename);
    } 
Inoltre in un'immagine jpg che ho caricato correttamente mi ritrovo lo sfondo nero che in partenza era bianco....

grazie