Analysis of Abstract-Graphical Pictures

We now turn to the more practical issue of making the information encoded in abstract-graphical pictures available to interactive systems. The problem is that while such pictures usually present information in a well-structured manner amenable to processing by machine, the vast majority of pictorial materials are stored only on paper, or, if within a computer, then in a data format (like bitmaps) that is difficult to access directly. This access is difficult because the structure must first be derived. While this is often trivial for a human reader, it can be hard to do with an algorithm. In this chapter, we develop a user-supported methodology to carry out this task.