EMD-KURTOSIS: A new classification domain for automated greek sign language gesture recognition

Sign Language (SL), structured on a set of gestures, is the communication channel between the deaf; this, however, requires extra intervention, such as SL translator, to facilitate the communication of the deaf with the hearers. Efforts towards automated SL translation have already reported in the literature. In this paper, a new approach is proposed towards this direction. In particular, data from three-dimensional accelerometer and five-channel surface electromyogram of the user's dominant forearm are analyzed using empirical mode decomposition combined with higher-order statistics (K₄EMD) towards the automated recognition of Greek Sign Language (GSL) gestures. The fourth-order moment, i.e., kurtosis, which is a measure of the deviation from the Gaussianity, estimated within overlapping observation windows for each of the intrinsic mode functions of the measured data was used as feature set for the classification of the signed gestures. The proposed feature set is evaluated with principal component analysis based on the Mahalanobis distance criterion to identify the effective scales of the intrinsic mode functions for the calculation of the fourth-order moment for each channel of the measured data that best discriminate between signed gestures of the GSL. The classification results from the K₄EMD analysis revealed that 90% of the inspected GSL gestures corresponding to ten words were correctly recognized, providing a promising solution to the automated GSL gesture recognition problem.