In this paper, we present a refocus interface to set the parameters used for diminished reality (DR)-based work area visualization and a multiview camera-based rendering scheme. The refocus interface allows the user to determine two planes — one for setting a virtual window, through which the user can observe the background occluded by an object, and the other for a background plane, which is used for the subsequent background rendering. The background is rendered considering the geometric and appearance relationships of the multiview cameras observing the scene. Our preliminary results demonstrate that our DR system can visualize the hidden background.