GPU-FV: Realtime Fisher Vector and Its Applications in Video Monitoring

TL;DR

GPU-FV is a GPU-accelerated Fisher vector extraction method enabling real-time video monitoring with high speed and comparable accuracy to traditional methods, outperforming some deep learning features especially with limited training data.

Contribution

This work introduces GPU-FV, a novel GPU-based implementation of Fisher vector extraction optimized for real-time video analysis, achieving significant speedups over CPU and non-optimized GPU versions.

Findings

GPU-FV is 12 times faster than CPU version.

GPU-FV processes frames within 34ms on standard hardware.

GPU-FV outperforms previous methods in real-time video monitoring.

Abstract

Fisher vector has been widely used in many multimedia retrieval and visual recognition applications with good performance. However, the computation complexity prevents its usage in real-time video monitoring. In this work, we proposed and implemented GPU-FV, a fast Fisher vector extraction method with the help of modern GPUs. The challenge of implementing Fisher vector on GPUs lies in the data dependency in feature extraction and expensive memory access in Fisher vector computing. To handle these challenges, we carefully designed GPU-FV in a way that utilizes the computing power of GPU as much as possible, and applied optimizations such as loop tiling to boost the performance. GPU-FV is about 12 times faster than the CPU version, and 50\% faster than a non-optimized GPU implementation. For standard video input (320*240), GPU-FV can process each frame within 34ms on a model GPU. Our experiments show that GPU-FV obtains a similar recognition accuracy as traditional FV on VOC 2007 and Caltech 256 image sets. We also applied GPU-FV for realtime video monitoring tasks and found that GPU-FV outperforms a number of previous works. Especially, when the number of training examples are small, GPU-FV outperforms the recent popular deep CNN features borrowed from ImageNet. The code can be downloaded from the following link https://bitbucket.org/mawenjing/gpu-fv.