Removing large scale fluctuations: divide by lowpass

In 1P movies there are enormous fluctuations of background that make viewing and analysis of the movies problematic, especially if you apply dff: (F-F0)/F0.

One option to remove these large scale fluctuation is to take a low-passed frame as F0 for each frame.

Mosaic App: Process -> Movie -> VLM -> Divide by low pass Empirically good value for the radius of the spatial filter is 200 pixels (on full resolution 1P movies).

You need to supply a binary vessel mask to this app. See [[How to create a mask of vessels][ for details.