is pan-starrs' data available to public users? Anybody knows that?

The data products are all images or star catalogs?

This is the link:
http://pan-starrs.ifa.hawaii.edu/public/
Looks like you've to be member of the PS1 Science Consortium to be able to log in.
And you'll need some database query knowledge, at least by using the PSPS Query Builder, or more advanced programming capabilities (XML, SOAP, Python, Perl). A short documentation of the database tables can be found here.
If you like to dig deeper into the database, this FAQ page may be a starting point.

The image processing pipeline (IPP) is described in this paper.