Here is my code :
foreach($_FILES as $key=>$photo){
if ($check[$key] == 'OK'){
$path = '../images/chevaux/' . $_POST['horseName'] . '_' . $horseID . '/' . $key . '.' . $file_extension;
$folder = '../images/chevaux/' . $_POST['horseName'] . '_' . $horseID;
if (!is_dir($folder))
{
mkdir($folder);
}
$filename = $photo['tmp_name'];
$percent = 4.08;
list($width, $height) = getimagesize($filename);
$newwidth = $width / $percent;
$newheight = $height / $percent;
$thumb = imagecreatetruecolor($newwidth, $newheight);
$source = imagecreatefromjpeg($filename, $path);
imagecopyresampled($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
imagejpeg($thumb, $path);
//....
All is working fine. Except that my pictures are completely black. The aim is to reduce their width and height by dividing them by 4.08. Know that uploaded image have width equal to 3264 px and height equal to 2448 px. Maybe it is too much?