Deep recurrent optical flow learning for particle image velocimetry data

A wide range of problems in applied physics and engineering involve learning physical displacement fields from data. In this paper we propose a deep neural network-based approach for learning displacement fields in an end-to-end manner, focusing on the specific case of particle image velocimetry (PIV), a key approach in experimental fluid dynamics that is of crucial importance in diverse applications such as automotive, aerospace and biomedical engineering. The current state of the art in PIV data processing involves traditional handcrafted models that are subject to limitations including the substantial manual effort required and difficulties in generalizing across conditions. By contrast, the deep learning-based approach introduced in this paper, which is based on a recent optical flow learning architecture known as recurrent all-pairs field transforms, is general, largely automated and provides high spatial resolution. Extensive experiments, including benchmark examples where true gold standards are available for comparison, demonstrate that the proposed approach achieves state-of-the-art accuracy and generalization to new data, relative to both classical approaches and previously proposed optical flow learning schemes. Particle image velocimetry is an imaging technique to determine the velocity components of flow fields, of use in a range of complex engineering problems including in environmental, aerospace and biomedical engineering. A recurrent neural network-based approach for learning displacement fields in an end-to-end manner is applied to this technique and achieves state-of-the-art accuracy and, moreover, allows generalization to new data, eliminating the need for traditional handcrafted models.