使用ImageMagick，您可以轻松，更快地创建缩略图，比使用PHP的容易得多。

 <?php
// Location to upload main image:
$mainDir = $_SERVER['DOCUMENT_ROOT'].'/images/l/';
// Location to create the thumb image:
$smalDir = $_SERVER['DOCUMENT_ROOT'].'/images/s/';
// Command to use:
$command = '/usr/bin/convert';
// Thumbnail width:
$size = 210;
// Make sure we have an image:
if(isset($_POST['submit'])){
    if(getimagesize($_FILES['photo']['tmp_name'])){
        $name = $_FILES['photo']['name'];
        $uploadfile = $mainDir . $name;
        move_uploaded_file($_FILES['photo']['tmp_name'], $uploadfile);
        $lrgImg = $mainDir . $name;
        $smlImg = $smalDir . $name;
        $imageMagick = $command . " '". $lrgImg . "' -resize '$size' '" . $smlImg . "'";        
        shell_exec($imageMagick);
    }
    header("Location: /test.php");
    exit;
}else{
?>
    <form action=" <?php echo $_SERVER['PHP_SELF']; ?> " method="post" enctype="multipart/form-data">
        <p><input type="file" name="photo" /></p>
        <p><input type="submit" value="Upload!" name="submit" /></p>
    </form>
<?php
    foreach(glob($smalDir.'*') as $img){
        echo ' <img src="'.str_replace($_SERVER['DOCUMENT_ROOT'], '',$img).'" /> ';
    }
}
?>