The method assumes the marker is placed on a relatively uniform colour background, such as room floors typically are. Thus, after we retrieve the marker corner points from ARToolKit, we expand them to cover also the maker’s white surroundings, and fill in the interior pixels by bilinear interpolation of pixels next to the white boundary of the marker. The method has general value for many other AR applications too, as markers are most typically placed on uniform colour walls, tables, etc. The method is fast enough even for real-time implementation, it produces
very good results in most cases, and in our application it is practically always better than showing the marker