GDlib imageantialias() not working

Question

How to get imageantialias() to work?

code:

imageantialias($image, true);

error:

Fatal error: Call to undefined function imageantialias() in /var/www...

info:

PHP Version 5.3.3-7+squeeze3
gd
GD Support  enabled
GD Version  2.0
FreeType Support    enabled
FreeType Linkage    with freetype
FreeType Version    2.4.2
T1Lib Support   enabled
GIF Read Support    enabled
GIF Create Support  enabled
JPEG Support    enabled
libJPEG Version     6b
PNG Support     enabled
libPNG Version  1.2.44
WBMP Support    enabled 

Answer 1

According to the manual,

Note: This function is only available if PHP is compiled with the bundled version of the GD library.

If your PHP version is > 5, this must be the reason why it's not available for you.