Robust optical flow estimation applied to particle image velocimetry images for high resolution velocity measurements

The article discusses application of Robust Optical Flow Estimation for increasing of Particle Image Velocimetry measurement resolution. Nowadays, one of the promising approaches for increasing the performance of the PIV systems is application of the Optical Flow Estimation for image analysis. Nevertheless, some of the OF implementations do not perform well in case of motion discontinues typically occurring in the PIV images. The purpose of this study is to validate the performance of the Robust Optical Flow Estimation. The tests were performed on simulated images of vortex flow and the results were compared with displacement fields calculated with the typical correlation PIV algorithm. The velocity for high and medium particle concentration was similar for Optical Flow and PIV-like analysis. Furthermore, the performance of the robust optical flow framework was tested with images corrupted with blurs and occlusions. The tests proved good performance of proposed analysis in case of non-Gaussian sources of measurement errors. The robust estimation framework performed well in the case of common image artefacts and proved to be a promising method for precise PIV flow measurements. The presented approach can be useful in development hybrid OF-PIV post processing software aimed for high-resolution measurements and provide a help in designing of experimental investigation of microscale fluid flow phenomena.

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Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).