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denoise profiled plug-in

Introduction

The denoise (profiled) plug-in forms part of the correction plug-in group and is used to denoise images, using a camera-specific noise calibration.

Blog-post describing the details behind the plug-in: http://www.darktable.org/2012/12/profiling-sensor-and-photon-noise/

todo: screenshot

This page is correct for the following stable versions of darktable

Reasons for use

The plug-in is used to denoise images.

What this plug-in actually does

See the blog post referenced above.

Parameters that can be changed

The following [parameters/settings] can be changed within this plug-in:

  • profile (calibrated for camera and iso value)
  • mode, non-local means or wavelet
  • patch size
  • strength
  • blend mode

profile

todo

mode

Method used in the denoising core. Non-local means works best for 'lightness' blending, wavelets work best for 'color' blending.

patch size

todo

strength

todo

blend mode

Standard blend mode is available for this module.

Generally recommended settings

The modules produces good results out of the box, possibly with a reduced strength or blend mode normal with reduced opacity.

A usual trick is to reduce chroma noise, while applying less denoise to luma (lightness), to avoid losing too much detail. Create two instances of the module, one with blend mode color and another with blend mode normal or lightness. Adjust the strength or opacity of the modules to taste.

Example usage

Example 1

TODO

Example 2

The [NAME] plug-in allows you to [manipulate/adjust/enhance/reduce/maximise/minimise/remove - delete as appropriate] VVVVVVVVVV to ....

In this example, you can see how the [NAME] plug-in [manipulates/adjusts/enhances/reduces/maximises/minimises/removes] ZZZZZZZZ and allows ....

Before photo screenshot - insert screenshot here
[Explanation of the original photo and what is hoped to improve/change]

Parameters used/suggested screenshot - insert screenshot here
[Explanation of the parameters used, and why - focusing on the reasons for using the values that you did.]

After photo screenshot to show changes - insert screenshot here
[Explanation of the photo following plug-in improvements and what has improved/changed]

NB.[Important to ensure that the before and after screenshots show only the effect of this plug-in, not a combination of other unspecified plug-ins or a stack of other adjustments. This example should focus on just the changes and improvements that can be achieved through the use of this plug-in. DELETE THIS TEXT ONCE THE EXAMPLE IS CREATED]

[Insert other examples as required]

Caveats

This module requires a noise profile to have been generated for the specific sensor or camera.

The blog post referenced above contains a description on how to perform such a calibration.

See also

http://www.darktable.org/2012/12/profiling-sensor-and-photon-noise/

Source code

darktable:source:src/iop/denoiseprofile.c

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