I want to create offline map tiles for JMapViewer from an image. How may I be able to achieve it? What are the tools used to generate those tiles?
There are different ways to reach that goal. All of them make use of an external toolchain:
1. Offline renderer
This is a bit more complex, as you need to use a renderer, a map style and OSM data packages to render your own map tiles on your box. A first simple way is to make use of Maperitive as it's very easy to configure and comes with styles. More advanced, you can setup a whole OSM rendering stack (Mapnik, PostgreSQL DB, osmosis, ...) so please see the tutorial at www.switch2osm.org
2. Tile downloader
This is pretty easy. There are different tools to download tiles from the official servers:
http://wiki.openstreetmap.org/wiki/Category:Tile_downloading
But please keep in mind that this machines are donated and should not be stressed by just a few single users. So the speed needs to be very moderate and respect the TUP:
http://wiki.openstreetmap.org/wiki/Tile_Usage_Policy