Generalized Polarization plugin for Fiji and ImageJ as described in [1].
To download the plugin click the following link: https://drive.google.com/file/d/1GRcjxbOY4tEVqvkXSn78gOEQEtry7lhW/view?usp=sharing
Copy the '.jar' file into your ImageJ/Fiji plugins folder. Restart ImageJ/Fiji. The GP plugin will appear in your Plugins menu as 'GP PlugIn'.
[1] Spectral Imaging to Measure Heterogeneity in Membrane Lipid Packing (2015) Erdinc Sezgin, Dominic Waithe, Jorge Bernardino de la Serna, Christian Eggeling. ChemPhysChem. DOI: 10.1002/cphc.201402794