SILK-SVM: An Effective Machine Learning Based Key-Frame Extraction Approach for Dynamic Hand Gesture Recognition

Dynamic hand gesture recognition is a fundamental domain in Human-Computer Interaction, wherein machine learning and deep learning models are widely employed. Key-frame extraction from the input hand gesture videos is a challenging task in this domain, since voluminous video datasets contain numerous redundant frames leading to storage inefficiency and longer training times. The existing approaches address this problem using various traditional and deep learning methods for this problem, aimed at extracting a fixed number of key-frames from all input videos. This paper introduces a novel skeleton-based silhouette-optimized K-means clustering mechanism (SILK) for dynamic Key-Frame Extraction. Initially, the hand skeleton features are localized on the video frames followed by frame filtering, consecutively, an unsupervised K-means clustering optimized by Silhouette score metric dynamically extracts an optimal number of unique key-frames from each video based on frame similarity. Effectiveness of the so extracted key-frames has been verified by SVM classification. The proposed approach (named as SILK-SVM) has been thoroughly tested on two publicly available datasets-IPN hand gesture dataset and the ASL (J&Z gesture) dataset. The experimental results obtained by SILK-SVM demonstrate a significantly higher classification accuracy (79.2% on IPN and 100% on J&Z gesture) with a frame reduction of 97% and 95% respectively, surpassing the two ablation models. Furthermore, a notable improvement over the state-of-the-art systems in terms of accuracy and frame reduction percent, with reduced complexity demonstrates the superiority of the proposed approach.