[질답/버그/제안] 급합니다 ㅠㅠ 뭐가 문제일까요 ㅠㅠ

Fatal error: Uncaught Error: Call to undefined function imagecreatefromjpeg() in /www_root/lib/thumbnail.lib.php:269 Stack trace: #0 /www_root/nariya/lib/content.lib.php(662): thumbnail('679593194.jpg', '/www/youngdong_...', '/www/youngdong_...', 400, 225, false, true) #1 /www_root/skin/board/NB-Basic/list/gallery/list.skin.php(173): na_thumb('http://youngdon...', 400, 225) #2 /www_root/skin/board/NB-Basic/list.skin.php(180): include_once('/www_root/skin/...') #3 /www_root/bbs/list.php(255): include_once('/www_root/skin/...') #4 /www_root/bbs/board.php(237): include_once('/www_root/bbs/l...') #5 {main} thrown in/www_root/lib/thumbnail.lib.php

on line269