When I build my D&D table I am highly considering using a TV inside the gaming table. But the issue is, how do I hide things? Most maps I know of have hidden areas shown in the D&D books and on online map generators.
Basically you need two things;
1) Fog of War; most of the VTT's out there can do this for you. Fantasy Grounds, Rolls20, Maptools, Battlegrounds, etc
2) Player ready maps. i.e. maps that don't have a big "S" or other symbol that indicates the secrets, traps, etc that will give away to the players what you don't want the players to see.
Folks have been using Fantasy Grounds to do this forever and you might find it useful to visit the forums over there and take a peek... and maybe ask your own questions if necessary. For example, the forums for Fantasy Grounds have a number of threads that you might find helpful. (And prove that you might find some guidance over there.) Here are a couple from a simple search of their forums...
The Adventurers League at my FLGS has at least 3 DMs that bring 36" monitors to the tables. You can buy 3rd party content for maps or modify them to create your own. Like photoshop there are different layers to the digital map. The DM layer has everything in on the map. You move what you want the players to see on the player layer when appropriate. It's great.
Are you just putting the map on the screen with photos, or are you using a VTT? Roll20, for example, has layers that can keep information hidden from the players, plus Fog of War which keeps unexplored areas blacked out.