Trimming Local and Global Self-intersections in Offset Curves Using Distance Maps

Abstract

The problem of detecting and eliminating self-intersections in offset curves is a fundamental question that has attracted numerous researchers over the years. The interest has resulted in copious publications on the subject. Unfortunately, the detection of self-intersections in offset curves, and more so, the elimination of these self-intersections are difficult problems with less than satisfactory answers. This paper offers a simple, and equally important robust, scheme to detect and eliminate local as well as global self-intersections in offsets of freeform curves. The presented approach is based on the derivation of an analytic distance map between the original curve and its offset.