HMM-based on-line multi-stroke sketch recognition

This paper describes a new approach for on-line multi-stroke sketch recognition. The approach is based on hidden Markov model (HMM). Sketches are modeled to HMM chains, and strokes are mapped to different HMM states. The proposed approach introduces a new method to determine HMM state-number, based on which an adaptive HMM sketch recognizer is constructed. A combined feature based on curvature, velocity and geometrical character of stroke for sketch recognition is also proposed to improve recognition accuracy. Finally, the experiments prove the effectiveness and efficiency of the proposed approach.