Which processes use linear VS non linear ?

[Aircrftr]

Is there a way to look at a process and know if it was designed to be used strictly on linear images, Non-linear or both?  It would be nice to have a way to know which process should be used on linear or non-linear or both....

Dan

[pfile]

https://pixinsight.com/forum/index.php?topic=4055.0

rob

[jkmorse]

Dan,

Rob cites the gold standard though that is now a bit dated, being produced before many of the existing tools even existed.  Here is my attempt to update that list:

Linear vs. Non-Linear Processing Steps:

Tools working on linear and non-linear images equally well:
AutoHistogram
CloneStamp*
ColorSaturation   
CurvesTransform – (other than saturation)*
DynamicAlignment
HistogramTransformation*
IntegerResample
Invert
MaskedStretch
NBRGBCombination
   RangeSelection
   RGBWorkingSpace assignment
   Rotation
SCNR*
   StarAlignment*
   StarMask*
Statistics
   processes that only alter the physical shape of the image

Tools best used on linear images:
AssistedColorCalibration
AutomaticBackgroundExtraction
ColorCalibration
CosmeticCorrection
Fast Rotation
Deconvolution*
DeconvolutionPreview
DrizzleIntegration
DynamicBackgroundExtraction*
Dynamic Crop*
Dynamic PSF*
GradientHDRComposition
GradientHDRCompression
GradientMergeMosaic
HDRComposition
ImageCalibration*
ImageIntegration*
      LinearFit*
MLT Noise Reduction*
ScreenTransferFunction*
SubframeSelector*
Superbias

Tools best used on non-linear:
ACDNR
CanonBandingReduction
ChannelCombination
CurvesTransformation - for saturation*
DarkStructureEnhancement
HDRMultiscaleTransform
LocalHistogramEqualization*
MorphologicalTransform*
ATWT Noise Reduction
MMT*
TGVD Noise Reduction*
SHO-AIP NB Combination*

That leaves the following uncategorized:

Processes:
ChannelExtraction
ChannelMatch
Convolution
DefectMap
DigitalDevelopment
FourierTransform
ICCProfileTransformation
InverseFourierTransform
LarsonSekanina
NoiseGenerator
RestorationFilter
SimplexNoise
UnsharpMask


*Tools I use on almost all of my images

These assessments show my personal bias so feel free to test using Tools in other categories to see if you come to different conclusions.

Hope that helps,

Jim

[Aircrftr]

Thanks for the info guys!
     It would really be nice if the developers could assign colors to the process title bars or something like that. I.E. linear processes would have their title bar colored blue, Non-linear blue and if it works in either state red/blue....   that way we could tell just by looking at it instead of keeping a list somewhere..