Using DSSImagerDownloader to help in background modelling

[Astrocava]

I have an image of crescent nebula, all surrounded of faint nebula. Using DBE with this image is difficult, so I tried a different approach:

- Using the DSSImager Downloader I recovered the image of that area.
- With DynamicAlignment I registered the downloaded image to fit my image.
- I selected the registered image as a mask
- I put the DBE samples over the darker areas
- I removed the mask and launched DBE

All went fast and without problems and I think I have a nice bacground model now. 


Sergio

[Nocturnal]

Very creative! Super idea actually. Of course you are assuming the DSS images don't have gradients in them

Can you show us two pictures that show the difference between the traditional DBE and DSS assisted DBE (DAD):

This could actually be automated.

[Juan Conejero]

Very interesting indeed. Please show us an example!

Of course you are assuming the DSS images don't have gradients in them

At least we know a Schmidt camera has no vignetting at all (provided the mirror is well dimensioned) 

[Astrocava]

Here some screen shots, will upload some step by step later.



The original image after registering and stacking, with the registered DSS image (had no time to cover all of my image  ), with an histogram transform and saturated to see the "good" background I have:

http://img33.imageshack.us/img33/4879/comparaoriginal.jpg

In each of the following images is a comparative of the DSS image downloaded and registered and my image after making the DBE correction, all with the same histogram transformation and saturation:


With DBE calculated in automatic mode over a stretched and saturated image, then applied to the base image:

http://img43.imageshack.us/img43/7571/comparaautoi.jpg

With DBE calculated in manual mode over a stretched and saturated image, then applied to the base image:

http://img33.imageshack.us/img33/6749/comparamanual.jpg

With DBE applied in manual mode over the dss image and more samples in the original image:

http://img33.imageshack.us/img33/861/comparadss.jpg


Some thoughts:

Last weekend, when I first posted this, I used the dss image as a mask to put the samples in DBE model, but today I change to put the samples in the dss image, throw DBE icon to workspace, open it again over my image. Will be a improvement to make this easy, to have the STF independently between the image and the mask. What I try to explain is that will be nice if you can apply the STF over the base image and/or over the mask to improve viewing the mask over the image.

I'm sure I'll have better results if the dss image covers all my image, there are still some artificial gradients

Sergio