Interactive beautification

We propose interactive beautification, a technique for rapid geometric design, and introduce the technique and its algorithm with a prototype system Pegasus. The motivation is to solve the problems with current drawing systems: too many complex commands and unintuitive procedures to satisfy geometric constraints. Interactive beautification system receives the user's freestroke and beautifies it by considering geometric constraints among segments. A single stroke is beautified one after another, preventing accumulation of recognition errors or catastrophic deformation. Supported geometric constraints includes perpendicularity, congruence, symmetry, etc., which were not seen in existing freestroke recognition systems. In addition, the system generates multiple candidates as a result of beautification to solve the problem of ambiguity. Using the technique, the user can draw precise diagrams rapidly satisfying geometric relations without using any editing commands.Interactive beautification is achieved by three sequential processes; 1) inferring underlining geometric constraints based on the spatial relationships among the input stroke and the existing segments, 2) generating multiple candidates combining inferred constraints appropriately, and 3) evaluating the candidates to find the most plausible candidate and to remove the inappropriate candidates. An user study was performed using the prototype system, a commercial CAD, and an OO-based drawing system. The result showed that the users can draw required diagrams more rapidly and more precisely using the prototype system.