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Bug #9996

Tonemapping produces Artifacts on soft edges

Added by Björn Sonnenschein about 5 years ago. Updated about 5 years ago.

Status:
Confirmed
Priority:
Low
Assignee:
-
Category:
Darkroom
Target version:
-
Start date:
06/23/2014
Due date:
% Done:

10%

Affected Version:
git development version
System:
other GNU/Linux
bitness:
64-bit
hardware architecture:
amd64/x86

Description

As the attached sample file shows, the tonemmapping module produces stepping and other artifacts on edges and some gradients.
This affects many situations, for exampe most images containing trees in front of a bright sky.

_DSC0116.NEF.xmp (7.29 KB) Björn Sonnenschein, 06/23/2014 02:46 PM

_DSC0116.NEF (5.02 MB) Björn Sonnenschein, 06/23/2014 02:47 PM

History

#1 Updated by Ulrich Pegelow about 5 years ago

  • % Done changed from 0 to 10
  • Status changed from New to Confirmed

Our tonemapping module uses Durand's algorithm from 2002 which involves a bilateral filter. It's a known shortcoming that it produces artifacts along strong aliased edges ([[http://cybertron.cg.tu-berlin.de/pdci09/hdr_tonemapping/tonemapping.html ]]).

Your example image is a typical case with strong aliasing due to the rather low resolution.

There seem to be some options for an improvement of the algorithm. I might have a look, but this will really take some time.

Recommendation: please try alternative modules like "global tonemap" and "shadows and highlights" which might also serve your purpose.

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