SpeedSeg: A technique for segmenting pen strokes using pen speed

We present SpeedSeg, a technique for segmenting pen strokes into lines and arcs. The technique uses pen speed information to help infer the segmentation intended by the drawer. To begin, an initial set of candidate segment points is identified. This set includes speed minima below a threshold, and curvature maxima at which the pen speed is also below a threshold. The ink between each pair of consecutive segment points is then classified as either a line or an arc, depending on which fits best. Next, a feedback process is employed, and segments are judiciouslymerged and split as necessary to improve the quality of the segmentation. In user studies, SpeedSeg performed accurately for new users. The studies also demonstrated that SpeedSeg’s accuracy is surprisingly insensitive to the values of many of the empirical parameters used by the technique. However, it is still possible to quickly tune the system to optimize performance for a given user. Finally, SpeedSeg outperformed a state-of-the-art segmentation algorithm. & 2010 Elsevier Ltd. All rights reserved.