Sometimes 1-Pixel-Artifacts from X-Trans Demosaicing

Software RawTherapee
1

Hello Community,
due to home office there is too much time to play around with photos!

I’d like to report some artifacts that appear in some cases with X-Trans images. When viewing in normal scale, the dots don’t stand out. But to adjust sharpening, I always use 100% view.

Here are three screenshots to visualize the problem:

  1. 3-Pass-Markesteijn

    demosaic_001_13052020_141146
    demosaic_001_13052020_1411461535×1200 766 KB

  2. fast

    demosaic_004_13052020_141217
    demosaic_004_13052020_1412171535×1200 725 KB

  3. using Iridient X-Transformer for demosaicing:

    demosaic_007_13052020_141551
    demosaic_007_13052020_1415511535×1200 686 KB

1-pass Markesteijn produces even more dots.

If necessary, I will upload the RAF and the DNG

2

Yes, please upload the RAF and the .pp3 you used

3

Okay, here they are:
DSCF4615.RAF (32.1 MB)
DSCF4615_RT-2.jpg.out.pp3 (12.8 KB)

This file is licensed Creative Commons, By-Attribution, Share-Alike.

Thanks for looking @heckflosse!

1 Like
4

Thanks a lot for the files.
There is definitely a bug somwhere. Left shows the dots, right does not show the dots. The only difference between left and right is, that in right I switched to Mono and then back to 3-pass (which should give the same result as in left)

grafik
grafik1920×1080 618 KB

1 Like
5

Can you post the content of your AboutThisBuild.txt ?

6

AboutThisBuild.txt (838 Bytes)

I use the newlocallab builds

7

Thank you, did not try this before. It is a nice workaround :+1:

No, the output jpeg shows the dots again

8

As expected…

9

At least I know now what causes the bug. And there is possibly already a fix in this pr:

Will check that now

1 Like
10

Here’s a before/after from above mentioned pr
left is using current (dev) behaviour, right is using camera wb for raw preprocessing

grafik
grafik1474×882 279 KB

2 Likes
11

Very big Thank You for merging the Raw preprocessing WB branch into dev! :pray:

12

I did not merge yet.

Edit: Is saw, rom9 merged \o/

Ah no, he merged dev into his branch. Anyway, tomorrow it will be merged into dev I guess. Then maybe another day to merge dev into the other branches (newlocallab for example)

1 Like
13

Doesn’t matter if it will take a few days to merge into all branches! Your reaction time here is ultra fast

2 Likes
14

Merged into dev \o/

4 Likes
15

@jdc Any objections to merge dev into newlocallab? If not, I will do that…

4 Likes
16

@heckflosse

Ingo
I just push a change before.
but after no problem you can merge.

Thank you

Jacques

1 Like
17

Done

1 Like
18

Thanks a lot to @heckflosse and @jdc!
Just downloaded RawTherapee_newlocallab_5.8-1964-g0436674b3_20200515. When using Preprocess White Balance mode = Camera the dots are much less prominent than before. Switching to Mono and back to 3-pass lets them disappear completely.

19

That’s a bug , though an interesting one :wink:

1 Like
20

A nice looking bug :beetle: :upside_down_face: