This paper presents a method for constructing object models from a single sketch image and optimizing their shapes. The sketch images used correspond to style sketches and all figures are drawn in three-point perspective, in which all lines ultimately converge on a common vanishing point. It is assumed that these images are drawn on paper by industrial designers. Basic models represented by Bezier curves are constructed based on straight homogeneous generalized cylinders (SHGC), using a contour image generated from the sketch image. Next, the shapes of the basic models are optimized by moving the control points of the Bezier curves with the use of genetic algorithms (GA). As a preliminary experiment, four methods of shape optimization are applied, using the same generation size. It is shown that the best of the preliminary methods may also be used for optimization of another kind of object model.
