Coherence-enhanced diffusion filtering applied to partially-ordered fluids

Abstract

Due to the increased interest in directly visualising partially-ordered fluids, there is a need for techniques that enable determining the associated director field from intensity images in robust and precise ways. Coherence-enhanced diffusion filtering (CEDF) is a computer vision technique designed to determine the local direction along which the intensity fluctuates the least. We pedagogically illustrate how CEDF can be applied to such partially-ordered systems using a microtubule-based active nematic as an example. In this system, the local microtubule orientation is visible using fluoresence microscopy. We illustrate how to choose parameters in the analysis, and demonstrate the technique is robust by applying it to data corresponding to an active nematic in flat space and an active nematic confined to the surface of a torus. Lastly, we show how to leverage topology to calculate the error in the analysis and find that in the examples presented, the influence of errors is negligible.

GRAPHICAL ABSTRACT

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by “La Caixa” Foundation.