Author Topic: "Pure RAW" or "Demosaiced RGB"?  (Read 181 times)

Offline Coastliner

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"Pure RAW" or "Demosaiced RGB"?
« on: 2019 March 11 01:56:20 »
Hi,

I am using a Canon 60D DSLR that produces .CR2 files. On a couple of tutorials it has been suggested that under Format Explorer I should select "Pure RAW" and debayer later on through the workflow rather than use "Demosaiced RGB". Is there an advantage to using "Pure Raw"? Or could I use "Demosaiced RGB" and not have to bother with the debayering process?

TIA,

Neil.

Offline John_Gill

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Re: "Pure RAW" or "Demosaiced RGB"?
« Reply #1 on: 2019 March 11 02:12:24 »
Hi,

I would use "Pure RAW" and then do the Debayer a bit later in the work-flow.

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Offline Coastliner

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Re: "Pure RAW" or "Demosaiced RGB"?
« Reply #2 on: 2019 March 11 02:27:36 »
Thanks John,

Why is it better to work in pure raw though? If I set it to Demosaiced RGB I could miss out a processing step.

Offline dld

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Re: "Pure RAW" or "Demosaiced RGB"?
« Reply #3 on: 2019 March 11 02:40:20 »
With the "Demosaiced RGB" setting PI will do the demosaicing behind the scenes (and for your calibration files too!). Demosaicing = interpolation and interpolation on darks and bias is not a good practice. Calibration with debayered data is also not a good practice. Furthermore, you'll have to work with larger files. By design PI is bayer-agnostic for calibration. You only need to debayer before registration.

Offline Coastliner

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Re: "Pure RAW" or "Demosaiced RGB"?
« Reply #4 on: 2019 March 11 03:34:34 »
OK, You'll have to excuse me, I'm new to this and at my age (66) my marbles are slowly abandoning ship.

Looking at Batch Preprocessing (see attached), If I select Pure Raw (in Format Explorer), then I have to leave "CFA" unchecked, right? Then the calibration phase of the batch preprocessing will work on the Pure Raw, then automatically debayer prior to registration?

(If you want to walk away from this I fully understand with good humour!)


Offline dld

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Re: "Pure RAW" or "Demosaiced RGB"?
« Reply #5 on: 2019 March 11 03:59:46 »
No worries, PI is as vast as a basement workshop with plenty of tools ;D

I don't use the BatchPreprocessing script so I might be wrong, but I think with "Pure RAW" you have to tick the "CFA Images" when working with DSLRs or other cameras with a Bayer matrix.

I am sorry, I wasn't aware that you're using the BatchPreprocessing script; hopefully someone more experienced will clarify this!

Offline pfile

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Re: "Pure RAW" or "Demosaiced RGB"?
« Reply #6 on: 2019 March 11 10:25:31 »
yes if you tick "Pure Raw" then you need to tick "CFA Images" as well. "CFA Images" is telling BPP that it needs to debayer after calibration.

CFA stands for Color Filter Array and is a synonym for Bayer Array.

rob