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Old 11-10-2015, 08:15 AM
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RickS (Rick)
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Join Date: Apr 2010
Location: Brisbane
Posts: 10,584
Quote:
Originally Posted by andyc View Post
Overlaying Paul's image showed the issue clearly - the sky background still had some blue in it, and I think I have a clean solution, at least for galaxies: use the 'background neutralisation' or 'colour calibration' in PI late in the processing.
The BGNeutralization and ColorCalibration processes are designed for use on linear data. I suspect they won't work well once you've started stretching. The best way to get a neutral background is to use BGN and CC early on and don't do anything in later processing to add a cast to the background. Failing this, you can always construct a mask exposing the background, e.g. with RangeSelection, and use CurvesTransformation to desaturate it.

Cheers,
Rick.
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