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Camera Support #12608

Noise profile: Canon PowerShot SX160 IS

Added by Hartmut Knaack 3 months ago. Updated 29 days ago.

Status:
Fixed
Priority:
Low
Assignee:
Category:
Darkroom
Target version:
-
Start date:
02/24/2019
Due date:
% Done:

100%

Affected Version:
git master branch

Description

Noise profile for Canon PowerShot SX160 IS using chdk.

darktable-noiseprofile-20190224.tar.gz (6.53 MB) Hartmut Knaack, 02/24/2019 01:39 AM

darktable-noiseprofile-20190413.tar.gz (5.98 MB) Hartmut Knaack, 04/13/2019 08:44 PM

History

#1 Updated by rawfiner - 3 months ago

  • Category set to Darkroom
  • Assignee set to rawfiner -

#2 Updated by rawfiner - 3 months ago

Hi
Just to be sure, is that all the possible ISO values for this camera? I mean, for instance, no value in between 800 and 1600?
The profile fits nicely for lower ISO values, but I am not confident about the values above ISO 1600 (included). It would be nice if you could remake the noise profile with a different set of images to be able to confirm the values obtained. :-)
Thanks

#3 Updated by Hartmut Knaack 3 months ago

The official camera firmware offers ISOs 100, 200, 400, 800 and 1600. The chdk-firmware-extension allowed to choose any custom ISO value from about 10 to 10000.
However, I don't possess this camera any more, so this is the only data I can provide.

#4 Updated by Anonymous 3 months ago

Spam deleted.

#5 Updated by rawfiner - 3 months ago

Ok, so I am afraid the only thing we can do is waiting to see if with a later version of the noise profiling tool we get better results...
Please keep your raw files, to be able to redo the profiling if it gets updated.

#6 Updated by Hartmut Knaack 3 months ago

OK. Will anyone update this ticket, once the tool received a significant update?
And can anyone point out, what kind of improvement is desired?

#7 Updated by rawfiner - 3 months ago

Yes, I will let you know.
Basically, (among other things) the curve fitting code could maybe be improved, which would maybe result in an improvement for your images.

#8 Updated by rawfiner - about 2 months ago

Hi,
Please could you try making the profiles again, after the following changes:
- copy darktable-gen-profile to old-darktable-gen-profile
- open the darktable-gen-profile file with a text editor
- change these lines:

        set xrange [0:0.35]
        fit f1(x) "$dat" u 1:(\$2**2):(1/max(0.01, \$5)) via a1,b1
        set xrange [0:0.8]
        fit f2(x) "$dat" u 1:(\$3**2):(1/max(0.01, \$6)) via a2,b2
        set xrange [0:0.5]

to:
        set xrange [0.1:0.35]
        fit f1(x) "$dat" u 1:(\$2**2):(1/max(0.01, \$5)) via a1,b1
        set xrange [0.1:0.8]
        fit f2(x) "$dat" u 1:(\$3**2):(1/max(0.01, \$6)) via a2,b2
        set xrange [0.1:0.5]

Then, save the file, and remake the profiles

#9 Updated by Hartmut Knaack about 1 month ago

OK, there you go.

#10 Updated by rawfiner - about 1 month ago

Thanks. Look ok to me.
I created a pull request: https://github.com/darktable-org/darktable/pull/2447

#11 Updated by rawfiner - 29 days ago

  • % Done changed from 0 to 100
  • Status changed from New to Fixed

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