Seedings at Olympics, like in Wimbledon or not?

So, can somebody tell me is the seeding is same like in Wimbledon or it's normal. I presume it's normal.

Since the field has 64 players, I presume it's 16 seeds like the Masters events.

Nope it will based on rankings according to the rulebook
Direct quote:
The selection of seeds for the Singles events shall be made by the
Referee based on the latest available recognised international
singles computer rankings. The selection of seeds for the Doubles
events will be at the discretion of the ITF, however the latest
available recognised international computer rankings shall be a
primary, but not sole, basis for such selections.

http://en.wikipedia.org/wiki/Tennis_at_the_2012_Summer_Olympics