<?php
// Le fichier
$filename = 'test.jpg';
$percent = 0.5;
 
// Content type
header('Content-type: image/jpeg');
 
// Calcul des nouvelles dimensions
list($width, $height) = getimagesize($filename);
$new_width = $width * $percent;
$new_height = $height * $percent;
 
// Redimensionnement
$image_p = imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
 
// Affichage
imagejpeg($image_p, null, 100);
?>