AP-TransNet: a polarized transformer based aerial human action recognition framework

Abstract

Drones are widespread and actively employed in a variety of applications due to their low cost and quick mobility and enabling new forms of action surveillance. However, owing to various challenges- limited no. of aerial view samples, aerial footage suffers with camera motion, illumination changes, small actor size, occlusion, complex backgrounds, and varying view angles, human action recognition in aerial videos even more challenging. Maneuvering the same, we propose Aerial Polarized-Transformer Network (AP-TransNet) to recognize human actions in aerial view using both spatial and temporal details of the video feed. In this paper, we present the Polarized Encoding Block that performs (\({\text{i}})\) Selection with Rejection to select the significant features and reject least informative features similar to Light photometry phenomena and (\({\text{ii}})\) boosting operation increases the dynamic range of encodings using non-linear softmax normalization at the bottleneck tensors in both channel and spatial sequential branches. The performance of the proposed AP-TransNet is evaluated by conducting extensive experiments on three publicly available benchmark datasets: drone action dataset, UCF-ARG Dataset and Multi-View Outdoor Dataset (MOD20) supporting with ablation study. The proposed work outperformed the state-of-the-arts.