Differentiable One-Line Drawings

Image-based one-line drawing seeks to turn a reference into a single stroke that preserves the subject's structure and provides a drawing process that users can inspect and imitate. Existing image generators can suggest the appearance of one-line art without providing a continuous path, while vector synthesis can change the reference geometry or route the stroke without following the subject's form. We propose a contour-guided differentiable framework that couples structural fidelity with locally organized drawing order. It first constructs a path along sampled foreground-boundary points, inserting attention-selected interior points near their closest boundary points. It then refines a cubic spline through image-feature matching and geometric regularization; optional width optimization varies line thickness along the stroke. An attachment-length bound explains the locality of the initialization. Progressive replay exposes the drawing order, as illustrated in the supplemental HTML. Our aim is to turn the visual economy associated with skilled one-line drawing into a process that non-experts can inspect, imitate, and experience.