Usage and generality of knowledge in the interpretation of diagrams

Considerable effort has been applied to the problem of picture interpretation, and in particular the interpretation of line drawings and diagrams. The paper surveys published approaches to line drawing and diagram understanding. A set of distinct processing levels that characterize the surveyed approaches is described, and five basic classes of knowledge which can be used to interpret line drawings and diagrams are then defined. The effect of these five classes of knowledge on the generality of an interpretation system is discussed, and the implications of using a particular class of knowledge at a particular processing level are considered in terms of system generality. A survey of current line drawing and diagram interpretation systems details the assumptions that follow from the sources of knowledge embedded in these systems. Finally, the use of knowledge in the surveyed methods, in relation to that proposed for an idealized and more general picture interpretation system, is discussed.