Viewing discarded data

[Synchronicity]

I'm hoping this is the correct forum for this question.  While I've been practicing my image processing I've been thinking about all of the data that DSS filters out of my images - I can't help but think it would be interesting to see what was discarded. I know it'll be mostly hot pixels, satellite trails and alien spaceships but there might be something worth seeing too 

Is there any setting in DSS or other stackers that would do this?

All the best

Michael

[vlaiv]

If you want to see everything that has been left out of the stack, there is a simple trick to do it in any software.

First create stack with all advanced features turned on like you normally would - hot pixel / cosmetic correction, some sort of sigma clip stacking, what ever you usually do to make image look "nice". Next thing is to do same with all the features turned off - use simple mean (average) stacking method.

Make sure that for both stack you select the same reference frame (so they are aligned properly).

Load both frames into some software that is able to do simple math operations (I think even Gimp can do this with two layers) - I usually do it with ImageJ. Simply create difference of two frames - second frame subtracted from first (or other way around, it makes no difference really). This frame will probably have some offset, but by using levels/stretch you will be able to adjust all details to be visible.

What is left is all the tiny details that have been removed by those "special software features" that remove stuff

 

[AngryDonkey]

PixInsight generates rejection maps (low and high) to give an indicationof how pixels have been rejected.