Three-dimensional focusing schlieren using a plenoptic camera

Many flows involve 3D density changes. These density changes can be qualitatively measured by optical imaging techniques such as schlieren imaging. In order to improve flow visualization a focusing schlieren system with threedimensional imaging ability is developed. The technology of a plenoptic cam...

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Bibliographic Details
Main Authors: Kerth, P, Hermann, T, McGilvray, M
Format: Conference item
Language:English
Published: ESA Conference Bureau 2019
Description
Summary:Many flows involve 3D density changes. These density changes can be qualitatively measured by optical imaging techniques such as schlieren imaging. In order to improve flow visualization a focusing schlieren system with threedimensional imaging ability is developed. The technology of a plenoptic camera allows to capture 3D information with a single photograph by recording the incident angle of incoming light rays. A plenoptic focusing schlieren system is set up and characterized to be able to resolve more than 25 focal planes in depth direction. The application of focus measures allows to infer simple 3D information from a focal stack generated by the post processing software. More complex 3D information is obtained by measuring the optical impulse response, the so-called point spread function. This is used to perform a full 3D reconstruction of flow objects from a single schlieren photograph.