Large Objects

I have a collection of images that I want to store in a database. The
collection is currently 12 GB. 
Can anyone give me some advice or links to any documents that discuss
the different methods to accomplish this. I already read techdocs
documents related to large objects. I just want some advice on good ways
to do it.
The database is going to be accessed through a Servlet (JDBC).
One thing that wasn't clear from techdocs was the disk space usage. If i
store 12 GB in the database without deleting it from the filesystem, it
is going to occupy another 12 GB. Is this right?
Thanks in advance.
nadim