I've tried to make a threshold effect with Filters.
I thought maybe Color Matrix could help me - thought fro some reason it made my object invisible.

I've realized there seems to be no way of achieving that.

I thought that a typical RGBA Curves filter would be amazing.

It'd allow creating some very interesting effects.

Would that be possible?

This is what https://developer.mozilla.org/en-US/doc ... ntTransfer is for.

But inkscape support for filters is really basic.
Don't expect a curve editor.

Below is an exemple of solarisation