Geometric information is needed to be handled to actualize this method, thusgeometric reasoning plays an major role in model-based vision. For thispurpose, we consider that it is important to be provided a mechanism, which allows a user to instruct one's intention explicitly, flexibly and graphically. To demonstrate the importance of this view on human interface, this paper presents a drawing editor prototype system of conceptual figures, DOGS, focused on relations among objects in a figure. In the system, a user can precisely provide his intention about the relations to the system by explicitly giving graphical indications. Given relations are preserved as constraints to offer flexible modifications of drawings.
DOGS can deal with two kinds of relations, primitive and macro ones.
The primitive relation represents a geometric relation among objects, and the macro relation is for a conceptual relation. In our embodiment, seven kinds of primitive relations are available. The macro relation is defined by the user as a combination of several primitive relations. The macro relations express highly structured relations, i.e., relations much closer to the user's concepts. DOGS realizes a proper drawing process for conceptual figures and a flexible visual user interface for the communication from user to computer.