More astro features

[w1g3y]

I see a request for dark frame removal in the list of issues, is it possible to tweak your averaging function to add a multiplying feature between frames.

I'm not an expert here, but I'm guessing it'd need a threshold value that could be customised, so that dark areas become darker (negative multiplication), and light areas become lighter.

A rudimentary imaging "stacking" feature, if you will.

Love your software, I use it all the time!!!