Movement Epenthesis Generation Using NURBS-Based Spatial Interpolation

Abstract

This study proposes a novel approach to the generation of video-based movement epenthesis for sign language and concentrates on a spatial interpolation approach using a nonuniform rational B-spline function to produce a smooth interpolation curve. To generate movement epenthesis, the beginning and end points are determined based on the concatenation cost, which is a linear combination of the distance, smoothness, and image distortion costs. The distance cost is defined as the normalized Euclidian distance between the palm locations at two cut points. The smoothness cost is determined by accumulating the second derivative of the curve. The image distortion cost is then estimated from the normalized Euclidian distance between the real and generated hand images. To evaluate the proposed approach, a set of sign video databases is collected and preprocessed with image calibration, content annotation, and principle component analysis. An image component overlapping procedure is also employed to yield a smooth sign video output. Evaluation results demonstrate that the synthesized trajectory is very close to the original trajectory. Moreover, the system was evaluated subjectively based on the results of ten hearing and five deaf people. The evaluation results also demonstrate the stability and feasibility of the proposed approach