我要上傳圖片就會發生以下的問題~~~想請教各位大大~~要如何解決
Exception message: imagecreatetruecolor(): requires GD 2.0 or later
Error code: 2
Stack trace is not available

Exception message: imagecreatetruecolor(): requires GD 2.0 or later
Error code: 2
Stack trace is not available

Exception message: Cannot add header information - headers already sent by (output started at /var/www/html/plog/class/object/exception.class.php:37)
Error code: 2
Stack trace is not available

Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 46080 bytes) in /var/www/html/plog/class/template/smarty/Smarty_Compiler.class.php on line 706