LinearFit producing odd results

[MikeOates]

I have an odd problem using LinearFit.

I have a 3 panel mosaic (landscape format) and after I had made the mosaic and combined the mono images to get RGB, one panel was rather green. So I went back to the separate integrated panels and did a LinearFit using the middle panel as the reference image. But the other panels turned posterized. See the image below showing the before and after with just STF active.



I also did the same by cropping the borders off, but that did not help. It was panel6 that originally had a green cast.

The .xisf  files for all three integrated green panels are here to try with:
http://www.mikeoates.org/pi/green_integrations_ngc7000.zip

Each panel is made from 15 x 600s subs. They were imaged on different nights so they are bound to be different hence the need for a LinearFit.

Using PixInsight 1.8.4.1193

I must be doing something stupid! so I hope someone can help

Thanks,

Mike

[msmythers]

Mike

Try clicking the 24 icon for 24 bit STF. That should take care of the posterized look.


Mike

[cfranks]

Mike,

I had a similar problem and Juan kindly told me why!  http://pixinsight.com/forum/index.php?topic=7713.msg51061#msg51061

Charles

[MikeOates]

Mike,

Yes I tried that, if does show a better image, but it is changed so much and a 24bit stf should not be needed.

Charles,

Thank you for the pointer, makes sense. I will have to do some manual adjustment to match the panels. I will have to think about that! possibly using pixel math.

So if anyone has a method for doing this and still keeping the images linear, I love to hear from you.

Thank you,

Mike