X-trans compressed -- status?


here is an example, processed .raf file, exported to jpeg. Please zoom to 100%

(Ingo Weyrich) #22

If you can provide the raw file I can check in RT without demosaicer

(Roman Lebedev) #24

FWIW if i convert that compressed RAF to uncompressed DNG, i see the exact same checkboard pattern.
So it’s unlikely to be incorrect CFA, too. And i still see it with demosaic off.
It’s likely either inherent “X-Trans moire”, or inherent compression algorithm deficiency.

darktable output with monochrome demosaic, from ADC uncompressed DNG:


Here is the .raf file
DSCF6956.RAF (29.4 MB)

(Ingo Weyrich) #26

Thanks for the .raf. Here’s the default processed jpg from RT. I didn’t try without demosaic, because the artifacts are not present in the rt demosaiced version.


I am sorry. What does it mean. The jpeg zoomed in shows the same jagged lines (if you zoom into the rope handle). None of these show in the original jpeg file which is nice and sharp (I took fine jpeg + raf).
Btw, I used LR CC (on my iPad) and opened the same .raf file, and the photo looks fine.

(Ingo Weyrich) #28

Ok, seems we talk about different issues:

Thats what I see when I zoom into your jpeg (screenshot from zoomed in area in Firefox):

And thats what I see when I zoom into the jpeg generated by rt (screenshot from zoomed in area in Firefox):

(Roman Lebedev) #29

Ok, now i got it. It was indeed a CFA problem.
Edit: looked through all the compressed raw samples for all 6 fuji cameras, it seems this was an isolated incident.

(Roman Lebedev) #30


Wow, that is fast action. I’ll recompile and try it again. Thanks.


Hi Roman. Just to let you know it rocks. Thanks.