image functions doe not work properly

Hi,

I am new to php program. I have a doubt about pear packages in PHP.
I have downloaded the pear packages through the command prompt line 'php go-pear.php' and installed it.
I could work with some examples for XML-RPC and give the correct output.
But when I try to work with an image example it give me the following error.

Warning: main(Image/Canvas.php): failed to open stream: No such file or directory in E:ImageTest ,Fatal error: main(): Failed opening required 'Image/Canvas.php' .

Why did this happened? In the pear package list I could find zip files like DB-1.7.6,Net_Socket-1.0.6,XML_RPC-1.3.3,PHPUnit-1.2.3,Mail-1.1.6, Mail-1.1.6 and XML_Parser-1.2.6 etc.. But I could not find any files related to Image. Should I install any GD library for image functions in PHP other than pear package.

Please help me.
Thanking in advance

From,
Vinod A.