Can this background be extracted?

[astrovienna]

Here is a linear image, after DBE: 

https://dl.dropboxusercontent.com/u/58468743/LumwithMay8Cropped2_DBE.fit

I get only marginal improvement with a second DBE.  In Photoshop, I can remove most of this by making an artificial flat, though it's a lot of work and not always a complete success.  On a stretched image, I would first clone out the brighter stars, then crop out the galaxy and fill in various parts of it with whatever background seems closest.  Then subtract that artificial flat.  Any suggestions for how to deal with this in PI?

Kevin

[Alejandro Tombolini]

Hi Kevin, you can use DBE. Attached is the process.
Saludos, Alejandro.

[astrovienna]

Hi Alejandro, I'm afraid I can't get the attached file to unzip.  Winzip reports it is empty.  But I did try a second DBE again, and I had much more success.  I take it the idea is to use a LOT of sample points?  I think I used 15-20 samples per row in the first DBE.  For the second DBE, I used 90 samples per row, and the background is pretty much gone.  Is that basically what you did?

Kevin

[Alejandro Tombolini]

Opps, that is strange!. Anybody else could download it?

Yes, add more samples, be sure none of them are over any star or galaxy and decrease smoothing factor to near zero (I used 0,020). The lower the value the more strict you have to be in not having any sample over stars.

I did not see the original image, but you should manage to extract the background with only one DBE

Saludos, Alejandro.

[llpastro]

I had to install Peazip to unzip other zipped files from PI.

Larry