Have learned a good bit so I thought that, in case there are others like me that stumble into this thread, the following could be helpful.
The links in the previous post provide useful information, although I don't recall anything there specifically answering my questions. I would suggest that newcomers avoid the last two links until they have a basic familiarity with PI and DBE as these are quite old and address a much older version of PI and, from what I can tell, a number of things have changed. OTOH, the DBE-example link does have discussion that I found most useful (but could have been misleading if that is where I had started).
1) You can define a 'center' in your image when placing sample points. Is this kind of like the 'center of mass' of the background you are trying to get rid of? Or ??
Per Juan in a 2011 post in this forum
"DBE's symmetries are now rarely used by astrophotographers ..."
2) You can set a tolerance. Does this number strictly apply to the process of placing and/or accepting valid sample points? Or is it also used in the actual processing.
From all I can tell this is simply a sample thing. My initial reaction to this parameter was that, given that some samples were 'richer in data' than others, that this might be used in processing. My best (uneducated) guess is that this is not the case.
3) I assume that the processing is happening in the frequency domain. Is that right?
Apparently not. I know a little about moving from the time to the frequency domain (and back) and this felt like that kind of problem (replace 'time' with 'spatial') sounding like a low frequency rejection filter. But I keep seeing references to interpolation which does not sound like a frequency domain action. I know almost nothing about topology math, but I would speculate that the answer to my question is 'no'.
4) My Process Explorer icon started out on the left side (with history, etc). How do I put it back there?
Finally stumbled into the little triangle that allows placement.
5) The DBE window seems to only link to a specific image when I hit the reset button (lower right) and an image has been selected. Seems odd to me - is there a normal way here?
This one was interesting! I had seen a number of references to 'clicking ON the desired image to connect DBE to that image'. To me that means 'click on the border'. And that doesn't work - you have to click IN the image (for some reason 'RESET' will select the image that you clicked ON, but reset is often not what you want). UI's can be subtle.
6) Not a DBE question, but can you delete a preview tab from an image window without deleting the whole window?
I thought that I had gone down this road, but apparently not. The Preview pulldown will do it. Also if your Preview image is sized such that there is extra gray area in the window, a right click gives you a handy context menu of options (similar to the Preview pulldown).
FWIW.
dave
ps. Despite start up frustrations, this is a most impressive piece of software.
