Php Function To Create Animated Gif

I am looking for a simple php function I can use to do the following

take a directory as the function input and output the filename of an animated gif with all image files in that folder.

so function should work like this..

$animatedgif = animatedgif(‘/home/account/public/images/’,$gifid);

All images should be resized and cropped to 240×180
there should be a delay of 0.4 seconds between frames
animated gif should be stored as $gifid.gif in a seperate folder

Thanks,
John