PHP : Saiz imej berdasarkan kadaran ( Proportional resizing image )

<?php
function scale_image($foto, $maxdim){
$thumb_width = $maxdim;
list($fullsize_width, $fullsize_height) = getimagesize($foto);
$thumb_height = @floor($fullsize_height/($fullsize_width/$thumb_width));
if($fullsize_width > $thumb_width){ $width = $thumb_width; $height = $thumb_height; } else { $width = $fullsize_width; $height = $fullsize_height; }

return '<img src="' . $foto . '" width="' . $width . '" height="' . $height . '" />';
}

echo scale_image('image.jpg', '500');
?>