Trouble with DBE?

[roberthurt]

I'm an occasional user, but the DBE is often what brings me to Pixinsight when working on datasets from Spitzer or other missions.

My problem is that I'm getting an odd error running DBE, though I don't think I'm doing anything differently than previous times (maybe 6 months ago?). Here's my workflow:

1 - Open up a large image.

2 - Set Auto STF (large dynamic range)

3 - Open DBE window. Begin clicking on background areas.

4 - After making about 20 samples I click the checkbox.

5 - I get an error message about there being fewer than three background samples selected.

I'm not sure what I'm doing wrong. Clearly there are a lot more than 3 samples selected. I'm attaching screenshots of the windows in case somebody might have a suggestion for me!

I'm running current versions of Pixinsight (fully updated) and Lion.

[Cleon_Wells]

Robert, I have seen this DBE error message on my MAC also, try increasing the Tolerance to 1.0 in the Model Parameter (1) section. I see that your Sample Generation number is high compared to what I see, which after I select my images jumps from the default of 5 to 14.
When you change the Tolerance setting select another  setting like Shadow relaxation, I have seen the changed setting not take effect until I do this other selection trick, this could be some bug in the MAC software.
Cleon

[Harry page]

Hi

All your samples are red meaning they are not included in the model ( hence the less than 3 samples report) as suggested increase the tollerance till your samples change from the red colour

Regrads Harry

[roberthurt]

Ah, thanks. The tolerance value (which I've never really messed with before) was the culprit, and opening it up validates my samples. Thanks for the help!

[pfile]

note also that if imageintegration leaves you with borders around the image which are not perfectly black, DBE's statistics can get confused and no amount of tolerance will fix your red samples. in this case you either have to crop first or replace the borders with the median pixel value with pixelmath.