Recognize my workplace

Hello guys,

for  a project I need to develop an augmented reality app for the gearVR.

Here the user sits in front of his desk with the gearVR on his head. We pass-through the camera picture for AR.

What we want to achieve is that the user only sees his desk including keyboard, mouse, display, coffee cup etc.

Also it should be possible to recognize the desk even when we add or remove objects from the desk.

Everything else in the room should be black.

Pictures attached explains the situation as well.

What is the best way, or how can we recognize such a big object.

From what I saw by now online I guess we need markers.

Thanks in advance

Chris