This paper presents a dense method of real-time registration of RGB-D image pair. So far, we have proposed the “see-through system”, in which multiple images acquired from RGB-D sensors are integrated to present images that is useful for confirming the shape or the positions of objects behind obstacles. However, errors of positional relation of sensors result in see-through images in which some objects are doubled or appear at incorrect positions. It is difficult to align the images because they are captured from distant viewpoints and there are few shared field of view. In the proposed method, positional relation of two RGB-D sensors is corrected using a new IRLS framework, fast and robust minimization strategy.