Process 2020

This is a quick guide that I currently use to process my astrophotography images.  The is a lot of other stuff I do and I may deviate from this from time to time.  Processing is like baking, there is a general recipe but there is also a lot of a 'pinch here' a 'dash there' which means there is a lot of variation in my processing.  Also, I just started using StarNet, the star removal software, which could  be used prior to combining NB images or after.

This current process is modified from a process that Gary Imm from Imm Astrophotography uses.  In addition, the section on deconvolution was from Visibledark Astro Video.  StarNet was first introduced to me from Chuck Ayoub of Chuck's Astrophotography.  Lastly, I am using a new method for combining RGB stars into starless NB images developed by Trevor Jones from Astrobackyard. 


Modified from Gary Imm
All subs (in PixInsight):
1. Use Blink, along with HFR from step 1, to eliminate bad images
2. Use Batch Preprocessing, with Cosmetic Correction, to develop LRGB masters
3. Use Dynamic Crop to frame object (apply to all 4 masters)
4. Apply APE/DBE to correct for gradients as necessary on each master
RGB:
5. Use ChannelCombination to combine R/G/B subs to obtain RGB
6. Apply Background Neutralization and RGBWorkingSpace to RGB (sometimes)
7. Apply TGV to RGB (noise reduction) see TGV Detail
8. Apply MLT to RGB (noise reduction)
9. Stretch RGB using Histogram Transformation (HT) to obtain RGBS
Lum:
10. Copy Lum and apply HT to create Lum-L (stretched Lum) see Deconvolution Detail
11. Apply StarMask to Lum-L to create Star Mask
12. Apply PSF to Lum to create PSF image
13. Using StarMask and PSF, apply Deconvolution to Lum (sharpening)
14. Apply TGV to Lum (noise reduction) see TGV Detail
15. Apply MMT to Lum (noise reduction)
16. Stretch Lum (HT) to obtain Lums
17. Apply HDR to Lums (range compression)
LRGB:
18. Match RGBS Luminosity with Lums using LinearFit (I currently adjust by sight)
19. Use LRGB Combination to combine RGBS and Lums to create LRGBS
20. Apply ACDNR to LRGBS (noise reduction)
21. Apply SCNR to LRGBS
22. Save as LRGBS TIF file for final touches in Photoshop, Lightroom, PI
(noise reduction, clarity, contrast, saturation, overall brightness)


TGV - Detail
1. extract L from the linear unprocessed RGB to create RGB_L
2. Then stretch RGB_L, copy it
3. then apply CurvesTransformation with the RGB/K settings at
- 0, 0.2 and 1, 0.5 to create a low contrast mask.
4. Apply this mask to the RGB and invert it.
5. Then apply TGV with these settings
- Strength of 5, Edge Protection of 0.000008, and Smoothness of 2. Use 500 iterations.
6. Preview and play with Edge Protection a bit for the optimal setting for a given image.
7. You want to be able to see the noise reduced slightly but not too much
- I never change the Strength, Smoothness, or Iterations values.
8. Make sure you check Local Support and use the RGB_L as the Support Image.



From Visibledark Astro Video -
Deconvolution Detail (Luminosity or NB Channels)
3-things: 1) Decon Mask, 2) Local Deringing Support Mask - LDSM, 3) PSF Image
Decon Mask - clipped mask (black)
1. HST tool to make nonlinear - Decon Lum
2. Stretch and clip Decon Lum
3. Rename identifier to Lum_Decon_Mask
LDSM
4. Starmask of linear image - default settings - Rename LDSM
5. Scale increase
6. Truncation - 0.25
Point Spread Function Mask
7. Scripts
8. Render
9. PSF
Deconvolution
10. PSF select
11. Add Lum_Decon_Mask
12. Richard-Lucy algorithm, Iterations 50-80
13. Deringing
14. Local Support - Starmask/LDSM
15. Preview
16. Global Dark from 1.000 to 0.200