Resizing images

[jbv at souslelogo.com]

Hi list,
I need to resize hundreds of jpg and png images.
Most images have different initial width and height,
and the resizing needs to be done according to data
in an xml file, therefore most resizing are quite
unique.
I was wondering : what is the best way to do it ?
1- with a LC script using export snapshot
2- or in php using a library such as Image magik ?

The main point is not how to do it, for I can code
both options, but rather : which option will ensure
the best image quality after resizing ?

Thanks in advance.
jbv