Fall detection using deep learning with features computed from recursive quadratic splits of video frames

Accidental falls are a leading cause of injury and death worldwide, particularly among the elderly. Despite extensive research on fall detection, many existing systems remain limited by reliance on wearable sensors that are inconvenient for continuous use, or vision-based approaches that require full video decoding, human pose estimation, or simplified datasets that fail to capture the complexity of real-life environments. As a result, their accuracy often deteriorates in realistic scenarios such as nursing homes or crowded public spaces. In this paper, we introduce a novel fall detection framework that leverages information embedded in the High Efficiency Video Coding (HEVC) standard. Unlike traditional vision-based methods, our approach extracts spatio-temporal features directly from recursive block splits and other HEVC coding information. This includes creating a sequence of four RGB input images which capture block sizes and splits of the video frames in a visual manner. The block sizes in video coding are determined based on the spatio-temporal activities in the frames, hence the suitability of using them as features. Other features are also derived from the coded videos, including compression modes, motion vectors, and prediction residuals. To enhance robustness, we integrate these features into deep learning models and employ fusion strategies that combine complementary representations. Extensive evaluations on two challenging datasets: the Real-World Fall Dataset (RFDS) and the High-Quality Fall Simulation Dataset (HQFSD), demonstrate that our method achieves superior accuracy and robustness compared to prior work. In addition, our method requires only around 23 GFLOPs per video because the deep learning network is executed on just four fixed-frame representations, whereas traditional pipelines process every frame individually, often amounting to hundreds of frames per video and orders of magnitude higher FLOPs.