Features and Limitations of Employing Reasoning in Description Logics for Sketch Recognition

Abstract

People intuitively use hand-drawn sketches as a way of communication and to conceive each other’s ideas. For better interactions with human users, it seems essential to endow machines the ability to understand hand-drawn sketches. The simplicity of using hands makes people prefer scribbling sketches over verbally expressing their thoughts or visually describing how they perceive objects in scenes. This is also motivated by the handiness of devices equipped with touch interfaces, which recognize human inputs only as raw gestures. But inherent properties of sketches, particularly impreciseness, make the process of recognizing hand-drawn sketches very challenging for computers. Moreover, there is a difficulty in finding a correspondence between low-level features of a sketched object and what humans have in mind about the same object as a whole concept. One way to resolve the indicated difficulties is to represent hand- drawn sketches in a high-level and formal way, so that machines can somehow easily understand and deal with them. A formal represen- tation reflects the human understanding of sketches in an application domain in terms of concepts that the sketches represent as well as in- terrelationships between the concepts constructing background knowl-