Air-writing recognition using reverse time ordered stroke context

Tsung-Hsien Tsai, Jun-Wei Hsieh, Chuan-Wang Chang, Chin-Rong Lay, Kuo-Chin Fan

Abstract: Highlights•A novel technique is proposed for recognizing any air-written trajectories without using any pen-starting-lift signal.•A backward time order stroke recognizer is implemented to characterize a writing trajectory in a backward manner. It can effectively remove redundant trajectory data.•A novel hierarchical arrangement technique that presents an air-written English alphabet tier by tier can well handle both the multiplicity and confusion problems.