Pixinsight question about color gradient removal

[konstantinos75]

This is my attempt with Pixinsight of the Pelican Nebula.
http://www.albireo.gr/astrogallery/nebulae/diffuse/2015.08.20/Pelican.html

I did my best to process this image but what I don't like is the purple color gradient at the bottom of the image.
This problem appeared probably because I did something wrong with DBE, background neutralization, color calibration on the RGB frame.
Another explanation could be some bad calibration applying the FLATs...


Do you know how I can get rid of this purple gradient?
I am interested to remove this on the final image, and not go back and do processing from the beginning (make RGB , add L, Ha...)

This is the final FIT image you can download it here if you want to play

https://www.dropbox.com/s/goqy6fyuronybkc/HaLRGB_final.fit?dl=0

Thank you

[RickS]

Hi Konstantinos,

A quick & dirty way to patch it up would be to use my ColorMask script (http://pixinsight.com/forum/index.php?topic=7751.0). Just create a magenta mask (click on the Magenta button, leave other settings at default), apply the mask to the image and then use CurvesTransformation to reduce blue and red.

Cheers,
Rick.

[konstantinos75]

Hi Rick

Thank you for your script.
I will try it and let you know :)

[RickS]

Let me know if I can help. I downloaded your FITS file and it worked quite well for me.

Cheers,
Rick.