How to create camera noise profiles for darktable

As already asked on github, can you please share the file(s), then I’ll have a look.

The script uses darktable-cli generated JPEG files to check for under/over-exposure, and makes wrong conclusions about under/over-exposure in RAW.

Please file a bug and explain the details of your findings.

This has already been raised by @Paolo_Benvenuto here:

I think the solution would be to turn of the “highlight reconstruction” module for JPEG conversion.

Trying to follow:

mkdir build
cd build
cd tools/noise
sudo make install

Change cd tools/noisecd ../tools/noise, but then:

$ make
make: *** No targets specified and no makefile found.  Stop.

What are you trying to achieve:

  • build the whole DT project with noise tools
  • build only noise tools?

in case of the latter, you can just:

cd tools/noise
mkdir build
cd build
cmake -DCMAKE_INSTALL_LIBEXECDIR=/opt/darktable ..
sudo make install

I was trying to build darktable and noise tools.

So perhaps the instructions should be updated with separate build within tools/noise.

Why did you do cd tools/noise then?
Without that it should work and build the whole darktable project including the noise tools.

Because darktable was built alright, but tools/noise were not.

At least for me it works, just those steps (as you outlined already):

mkdir build && cd build
sudo make install

Somewhere during the build process you should come across this output:

Scanning dependencies of target darktable-noiseprofile
[  9%] Building C object share/darktable/tools/noise/CMakeFiles/darktable-noiseprofile.dir/noiseprofile.c.o

After successfull build & installation you should find the noise calibration tools here: /opt/darktable/libexec/darktable/tools

Just tried compiling entire darktable once more and I do get /opt/darktable/libexec/darktable/tools/darktable-noiseprofile.

Then what is

mkdir build
cd build
cd tools/noise
sudo make install

for? If compiling tools only, shouldn’t cd tools/noise be the first line?

Where did you find this line cd tools/noise in the instructions? It does not make any sense after you already changed into the build folder.

If you only want to build the noise tools follow my instructions here: How to create camera noise profiles for darktable - #176 by da-phil

It’s in this very article we are commenting on, STEP 1a.

Ups, I completely forgot about that, I was only thought about README files :smiley:
Well, then we should ask @asn to update the article before more people fall into the same trap.

Anyone can update an article, just make a pull request against our github.

First, any manual in how to understand the generated PDF?
noise_result.pdf (337.2 KB)

noise_result.pdf (352.3 KB)

Second, any benefits of using multiple raw files for each ISO? For example like ISO 800 in the print screen.

Third, a thing I found was when I tried to create a noise profile for DJI Air 2. This camera has 12 Mpix and 48 Mpix. I am able to create two noise profiles, but the camera model names are the same for them, so I can’t separate them later in the .json file. Any clue or just to forget it and use one for both?

I think I did not correctly understand the process. It seemed obvious though.
First, one has to open wide the lens at iso 100 (or, I guess, the lowest real one), but still see details, hence the need to eventually decrease the aperture. That, I think I understood.
But, then, one has to make the picture dark - but how ? The only way would be to decrease the aperture at its lowest value. And then I feel totally puzzled.
That sounds not very obvious to me, and this could explain why I could not success so far.
Could someone please explain this to me - and be indulgent - ?
Thanks in advance.

Large aperture, set the lens to infinity. I used a bright window and with a black curtain beside so that I could get both clipped highlights and crushed shadows.

So, in fact, just find the correct setting to start from at iso 100, and then just change the speed according to the sensitivity and that’s all.
The part I was refering to is Now you need to set the shutter speed. Make the picture really dark and then make the shutter speed longer till the gap which gives us the white from the monitor is overexposed, pure white see Figure 4. The black around the white paper should be underexposed (pure black).
Maybe some cut/paste leftover…

Upload a sample and we can check what will need to be done.