Author Topic: Color Gradient Problem - ask for help  (Read 853 times)

Offline terrycyc0214

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Color Gradient Problem - ask for help
« on: 2018 April 22 23:05:21 »
Dear

I have the problem to remove the color gradient completely.  Can anyone help and show me how to remove it....

Here is the link of the image (after linearfit and RGB combination)

Regards,
Terry

https://drive.google.com/file/d/1hpa6wXdh6yESzR1t7jvZMQn8N8USyeQh/view?usp=sharing


Offline avastro

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Re: Color Gradient Problem - ask for help
« Reply #1 on: 2018 April 23 02:02:33 »
Here is my try, using ABE, I ajusted tolerance and deviation.
Get same results using DBE a bit more tedious.

Antoine
Antoine
Lentin Observatory
http://www.astrosurf.com/avastro/

Offline wimvb

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Re: Color Gradient Problem - ask for help
« Reply #2 on: 2018 May 08 11:50:06 »
DBE with samples placed inbetween clouds of ifn. Since you have delicate ifn in this image, you don't want to destroy it with careless DBE.
I usually place few samples, make them rather large, and can have multiple passes of DBE. If I do multiple passes, I adjust Tolerance such that Sample Weight is above the Minimum Sample Weight limit.
Wim

AZ EQ6 GT + EQ3 PRO, SW 150P, ZWO ASI174MM-Cool, Pentax K20D (retired),
SW ST80 + ZWO ASI120MM + Lin_guider

Offline MikeOates

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Re: Color Gradient Problem - ask for help
« Reply #3 on: 2018 May 10 06:34:58 »
...I adjust Tolerance such that Sample Weight is above the Minimum Sample Weight limit.

Wim, can you please explain what you mean by Sample Weight? I can see the Minimum Sample Weight limit, but where does the Sample Weight come from?

Thanks,

Mike

Offline wimvb

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Re: Color Gradient Problem - ask for help
« Reply #4 on: 2018 May 10 15:33:49 »
The sample weight is in the upper panel of the DBE tool, in the three boxes called Wr, Wg and Wb, and shows the weight for red (Wr), green (Wg), and blue channel (Wb)
In this image it's grayed out (no sample selected)
Wim

AZ EQ6 GT + EQ3 PRO, SW 150P, ZWO ASI174MM-Cool, Pentax K20D (retired),
SW ST80 + ZWO ASI120MM + Lin_guider