Nonlinear stretch: MultiScaleAdaptiveStretch or HistogramTransformation
(Optional) Combine L with RGB
CurvesTransformation to adjust the colors
Crop: DynamicCrop
Rotate: FastRotation
Resample or IntegerResample
SampleFormatConversion to convert floats to uint8 or uint16
Save final image
Calibration, Alignment, and Stacking
Use the Script -> Batch Processing -> WeightedBatchProcessing (WBPP) to do
everything up to and including stacking images, for all filters at once.
The "Grouping Keywords" section of WBPP window can be used to group targets or
parts of a mosaic. Make sure pre and post are checked or the script will try
to put all of your mosaic tiles on top of each other. Also select Registration
Reference Image Mode "auto by ...." The file names must all have the same
keyword before the target/part name, each separated by an underscore. For
example *_target_M1_** or *_part_x1y2_.
Image Inspection
Process -> ImageInspection -> SubframeSelector
Eccentricity goes up (bad) as FWHM goes down. Less than 0.42 is considered round on the PixInsight Forums
Process -> ImageInspection -> Blink
Script -> Image Analysis -> ImageSolver plate-solves an image
Script -> Image Analysis -> AberrationInspector zooms in on the center, edges, and corners of an image
Script -> Image Analysis -> FWHMEccentricity
Must be grayscale images
Click Support to see how they vary over the image
Background Extraction, Deconvolution, and Noise Reduction
BlurXTerminator and NoiseXTerminator are AI-based paid plugins from RC Astro
DynamicBackgroundExtraction: auto-generate points and then add/subtract points as needed replaced with MuliscaleGradientCorrection
MultiscaleGradientCorrection with MARS data, you must run SpectrophotometricFluxCalibration first
BlurXTerminator: make sure to create previews so you can test out settings quickly with the sliders; I like the defaults
NoiseXTerminator: make sure to create previews so you can test out settings quickly with the sliders; I like more noise than the defaults
Color Correction
Process -> Color Calibration -> SpectrophotometricColorCalibration is the state of the art (Official Documentation)
Make a preview of the background, and put it into the region of interest box
Make sure the QE curve and filters match the imaging hardware (or are close)
Use Ideal QE Curve for Bayer-filter cameras
Update the White Reference to taste--this is the desired white balance of the image
Process -> Color Calibration -> Background Neutralization may also be helpful; use the background preview as reference
Process -> Color Calibration -> Color Calibration is the oldest option. It calibrates the image to a spiral galaxy, or similar
1. Use the background preview as the background reference
2. For the white reference use
- A preview of a spiral galaxy in the image
- The whole image (all of the stars approximate a spiral galaxy)
Cosmetic Processing
(Optional) Create a star mask
Use Process -> IntensityTransformation -> CurvesTransformation to tweak the colors
Use Process -> IntensityTransformation -> HistogramTransformation