Here are my (quick & dirty) processing steps...
Luminance:
- Crop
- DBE to remove background gradient
- Slight deconvolution - PSF sampled with Dynamic PSF, large star mask as local deringing support, clipped luminance mask to restrict decon to high signal areas
- MultiscaleLinearTransform noise reduction using linear mask
- HistogramTransformation stretch
- Apply star mask: MorphologicalTransformation with Selection for mild star reduction
- Clipped lum mask with stars removed: light LHE
- Clipped lum mask with stars removed: slight MLT sharpen
RGB:
- LRGBCombine R/G/B
- Crop
- DBE
- ColorCalibration with galaxy as white reference
- MLT noise reduction with linear mask
- HT stretch
- ACDNR noise reduction, heavy on chrominance noise
- RGBWorkingSpace 1:1:1 (only affects lum extraction for masks)
- Clipped lum mask: Curves saturation boost
- Star mask: use MLT to blur chrominance (remove first few layers, set target as Chrominance). This helps improve star colour.
- Hue curve to move cyans -> blue
Final combine:
- LRGBCombine: combine Lum and RGB
- Clipped lum mask: Curves saturation boost
- ColorMask blue mask: curves boost blue, slight red boost, sat boost (ColorMask is my script, available from the PI forum)
- Clipped lum mask: slight MLT noise reduction
- Adjust black point
A clipped lum mask is created by taking luminance (copy of Lum data or extracted from RGB) and using HT to clip the bottom of the histogram.
A clipped lum mask with stars removed is created from a clipped lum mask and a star mask. I typically use a PixelMath expression like: "iif(star_mask>0.1,0,$T)" applied to the clipped lum. After removing the stars I'll use a mild Convolution to blur things up a little so there aren't hard edges.
If any of my other shorthand isn't clear, just ask.
Cheers,
Rick.