Fatal error: Call to undefined function getiamgesize() in?D:\www\shopImooc\test\resizeImage1.php?on line?3

<?php
$filename="ad.jpg";
list($src_w,$src_h,$imagetype)=getiamgesize($filename);
$mime=image_type_to_mime_type($imagetype);
echo?$mime;

運(yùn)行報(bào)錯(cuò)，怎么辦呢