Print Email Facebook Twitter Elimination of unsteady background reflections in PIV images by anisotropic diffusion Title Elimination of unsteady background reflections in PIV images by anisotropic diffusion Author Adatrao, S. (TU Delft Aerodynamics) Sciacchitano, A. (TU Delft Aerodynamics) Date 2019-03 Abstract A novel approach is introduced that allows the elimination of undesired laser light reflections from particle image velocimetry (PIV) images. The approach relies upon anisotropic diffusion of the light intensity, which is used to generate a background image to be subtracted from the original image. The intensity is diffused only along the edges and not across the edges, thus allowing one to preserve, in the background image, the shape of boundaries as laser light reflections on solid surfaces. Due to its ability to produce a background image from a single snapshot, as opposed to most methods that make use of intensity information in time, the technique is particularly suitable for elimination of reflections in PIV images of unsteady models, such as transiting objects, propellers, flapping and pitching wings. The technique is assessed on an experimental test case which considers the flow in front of a propeller, where the laser light reflections on the model's surface preclude accurate determination of the flow velocity. Comparison of the anisotropic diffusion approach with conventional techniques for suppression of light reflections shows the advantages of the former method, especially when reflections need to be removed from individual images. Subject particle image velocimetryimage pre-processinganisotropic diffusionbackground removalunsteady light reflections To reference this document use: http://resolver.tudelft.nl/uuid:bd62b547-e175-4c3c-9699-65785e3d2437 DOI https://doi.org/10.1088/1361-6501/aafca9 ISSN 0957-0233 Source Measurement Science and Technology, 30 (3) Part of collection Institutional Repository Document type journal article Rights © 2019 S. Adatrao, A. Sciacchitano Files PDF Adatrao_2019_Meas._Sci._T ... 035204.pdf 4.72 MB Close viewer /islandora/object/uuid:bd62b547-e175-4c3c-9699-65785e3d2437/datastream/OBJ/view