SH 108 Scrollable Annotated Image

This is a remastering of the original 2012 display.

Processing Sequence

I thought it would be useful to record what I did. As is my current practice the first thing I do is build masks.  After combining the colors I extract a luminance.  I then make a copy and HT it.  Most of the star masks are based on the linear version.  The bright, midtones, and shadows masks are based on the non linear with stars removed.  The bright mask was built using ACDNR on the non linear

Tool Mask Reason
Channel Combination
Combine source images.  Each had been separately mosaic
Fits Header
Add the WCS coordinates to the file.  The linear L was used for the solution.
Color Calibration ~star mask Using a carefully chosen sample area for a white reference I increased the amounts of red and blue relative to green
Curves bright mask increase the color saturation of the bright areas
Curves star mask remove any color from the stars
make the image non-linear.
remove some of the pedestal in the image
Curves bright mask tweek the saturation more
HDRMultiscaleTransform bright mask Using Linear 3 I increased the contrast between light and dark areas.  Linear 3 gave the most interesting result
Curves bright mask Increase the brightness of the bright areas
Curves midtones Try to bring up the midtone areas.  This was not enough and I retried later with a fancier mask
MultiscaleMedianTransform bright mask sharpen the image by selectively increasing certain wave sizes and applying noise reduction
A script that increases the contrast of dark features
TGVDenoise shadows reduce the noise in the shadows
HistogramTransformation shadows further darken the shadows
PixelMath Sadar halo Sadar was pretty blown out at this point.  Replace it with the non Linear L image
Curves Color Mask Sadar had a purple halo.  Color mask is a new script that searches for a particular color range and builds a mask for it.  In the case of my images stars tend to get purple halos.  Most were prevented using star masks, but that did not work for Sadar and a couple of other bright stars.  Thus by carefully selecting colors I built a mask for this and other halos.  I then partially desaturated these leaving some of the color (since I liked the effect).
Curves bright mask I wanted to increase the midtones.  To prevent loss of contrast I first increased the brightness of the bright areas
Curves midtones2 Using a carefully constructed mask I increased the midtones in the range of the feathery nebula and also did a mild increase of the some of the dimmer midtones
TGVDenoise midtones2 Doing these increases increased the noise.  I used TGVDenoise in Lab mode to apply noise reduction to the chrominance without affecting the detail of the luminance
Curves shadows some more reduction of the background to increase contrast

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Creative Commons License (c)2015 Robert J Hawley.  Some Rights Reserved.
Except as noted, all work on this site by Robert J. Hawley is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. This permits the non commercial use of the material on this site, either in whole or in part, in other works provided that I am credited for the work.