How to choose a demosaicing algorithm

[Peter]

Sadly, yes. darktable is way better.

[roddy (Roddy González)]

Thanks for the comparison.

I see noisy dots more noticeable and reddish in PPG in “LMMSE vs PPG” photo.
AMaZE and LMMSE looks the same to me.

It truly seems that I have to see a 200% crop to start noticing some differences.

[Peter]

I see the colour dots even at 100% and with all demosaicing methods but LMMSE.

I haven’t tried this one, but there is a raw sample from Mavic here https://raw.pixls.us/getfile.php/1052/nice/DJI%20-%20FC220%20-%2016bit%20(4:3).DNG

[hannoschwalm (Jens-Hanno Schwalm)]

@roddy

I see noisy dots more noticeable and reddish in PPG in “LMMSE vs PPG” photo.
AMaZE and LMMSE looks the same to me.

It truly seems that I have to see a 200% crop to start noticing some differences.

This all depends at lot on the raw data. This image is likely a pretty easy one for a demosdaicer, no very-high/very-low transitions on single color channels. Also the lens looks “not too sharp”. Things get interesting in parts like “sun on sea at a beach”. Likely lots of reflections on the water. Or on small stones.

Also not that in dt as in other developers there are many steps following the demosaicer. You might rotate a bit for example and immediately the overshoots (like most obviously in PPG) will lead to further errors.

@roddy

It truly seems that I have to see a 200% crop to start noticing some differences

Well - a demosaicer works on pixel-level

[Peter]

VNG4 vs RCD at 200%. VNG4 gives moire but smoothes the sky. RCD gives more digital noise in the sky but almost no moire and better details of the aircraft.

For a picture like this I normally go for dual demosaicing. RCD+VNG4.

[afre (Alan)]

Speaking of RCD, a while back, its dev (@LuisSanz) indicated that he wanted to improve it. I wonder if there was any progress. Pinging him in case he would like to comment in this thread.

[Thanatomanic (Roel)]

@paperdigits

@hatsnp

On the topic of demosaicing, is there any change there’ll be new ones investigated for the x-trans filter

The research is often done by people in academia, who then publish a paper. That paper is picked up by some FOSS Dev and implemented. Maybe searching Arvix or another academic database will yield something.

Some clues for alternative (academic) methods: Google Scholar with search terms (demosaicing OR demosaicking) x-trans -neural -deep

[afre (Alan)]

@Thanatomanic

-neural -deep

LOL - it is common practice for me to negate these keywords as well mostly because my laptop can’t handle it, let alone normal processing. That said, I don’t think there is much out there. More papers are on novel mosaics such as ones with yellow and/or white and/or extra circuitry in the pattern as far as I have found.