Free-Hand Stroke Approximation for Intelligent Sketching Systems
Tevfik Metin Sezgin, Randall Davis · 2001
Introduction Free-hand sketching is used extensively during the early design phases as an important tool for conveying ideas, guiding the thought process, and serving as documentation (Ullman et al., 1990). It also provides a natural way of interaction desirable in the context of E21 and intelligent design spaces. Unfortunately there is little computer support for sketching. The first step in building a sketch understanding system is generating more meaningful descriptions of free-hand strokes. We describe a system that takes strokes described by an array of points along with timing data, and generates such descriptions in terms of geometric primitives such as circles, polylines, curves and their combinations. 2. System Description 2.1 Issues Loss of information due to digitization, noise in the data, imprecision due to freehand sketching and sparseness of sampled data points -- which may be as low as 4-5 dpi as opposed to scanned drawings that may have 1200-2400 d