Selecting interpolation in script

I’d like to know how to switch to PPG interpolation method (which is the best one according to the documentation) when using script, in the directive convert/convertraw (or everywhere else it is supposed to go). Is it an option of -debayer, or something like that ? Command line documentation doesn’t mention it. The context is: DSRL unfiltered raw files (NEF/CR2/ARW).

Thank you !


PPG is not the best one.
Also this interpolation is only used by libraw when directly doing the debayer from RAW file.
In script files you generally convert your RAW into FITS CFA then you apply the debayer. In this case no PPG. The best one is RCD which is the default one.

Hi lock042, thank you!
Ok, I was (and probably still am) missing some knowledge…
So I can assume that RCD is used by default.
Anyway I still wonder how to select a different interpolation method in the script (from GUI it is selected in the Preferences).

(My purpose is to automatize everything from bash shell by customizing the siril input script using unix tools (awk, sed, grep, etc.) starting from my raw files.)

Thank you!


The algorithm used (even for scripts) is the one defined in preferences.

I would advise to let default settings however.

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Ok thank you.
I expected a command line behaviour more independent of the whole gui application.
But it is perfectly ok like this.


Hi lock042,
I’ve been checking for a while. First I didn’t find the RCD interpolation algo (Siril 0.99.6, the latest, no updates available) in the drop down menu, but only Bilinear, AHD, VNG, PPG, DCB as shown in the attached png file.
Furthermore, despite the PPG interpolation is set in the preferences, the command line is still using the VNG. I am probably missing something…

Yes but you are not watching the right thing. As I said here it is the libraw settings. You need to check the FITS /SER debayer settings.

Whoops! I was completely confused !
Ok, the RCD is selected by default.

To be clear enough, I’ve added an explanation text.

Ok thanks, I guess it will come with next Beta3…
I start suspecting that I am doing the wrong workflow, that could be the reason of the other issue I’ve described on another Topic (about Siril not finding stars for registration), in particular concerning the RAW conversion.