Abstract: We provide a method for extracting and classifying stroke segments from a line drawing or sketch with the goal of producing perceptually-valid output in the context of mesh inflation. This is important as processing freehand sketch input is a fundamental task in sketch-based interfaces, yet many systems bypass the problem by forcing simplified, unnatural drawing patterns. Our stroke extraction combines contour tracing with feature-preserving post-processing. The extracted strokes are classified according to the objects and regions in the sketch: object and region boundaries, interior features, and suggestive lines. The outcome of this classification is demonstrated with examples in feature-sensitive mesh inflation.