This is a BlinkScript version of a weighted Median method for Bayer demosaicing. It supports different CFA arrangements and also handles alpha channels by reconstructing them from green. For proper color fringes I would advise you to run this filter on the final comp though, as in reality the Sensor artifacts would be among the last imperfections to happen before storage/compression. (Images at 200% to better show the artifacts)

I found this filter quite handy to match CGI with plates and if you add a random offset per-pixel (+/-) before applying it you can get some nice digital noise patterns for free: