Smoothing application enhancement

Summary

Some modifications of the Smoothing application. In particular the Gaussian mode now has two additional parameters : type.gaussian.maxerror and type.gaussian.maxwidth. These parameters were available in the ITK filter, but were not exposed in the application

Closes #1961 (closed)

Implementation Details

Applications

Smoothing :

• new parameter type.gaussian.maxerror : The algorithm will size the discrete kernel so that the error resulting from truncation of the kernel is no greater than type.gaussian.maxerror
• new parameter type.gaussian.maxwidth : Set the kernel to be no wider than maxwidth pixels, even if type.gaussian.maxerror demands it.
• the radius parameter has been renamed into stdev (because this is what it is, see the TODO in code)
• Some modernization (auto, RegisterPipeline())

FastNLMeans :

• Some modernization (auto, RegisterPipeline())

Tests

The tests for the Smoothing application have been updated:

• New test for the Gaussian mode (there was no test for this mode)
• New test for the Anisotropic mode (there was no test for this mode). Note that I needed to set a tolerance value for this test (1e-6), because the result were different on windows 8 (x86). The differences are probably caused by numerical error, and we can't do much about it anyway because we are using an ITK filter.
• The apTvUtSmoothingTest_InXML now depends on the apTvUtSmoothingTest_OutXML test, instead of using a stored baseline.
• The apTvUtSmoothingTest has been removed, there is no need to test 3 times the mean mode with the same parameters. (see InXML and OUTXML tests).

Copyright

The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.

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Check before merging:

• All discussions are resolved
• At least 2 👍 votes from core developers, no 👎 vote.
• The feature branch is (reasonably) up-to-date with the base branch
• Dashboard is green
• Copyright owner has signed the ORFEO ToolBox Contributor License Agreement
• Optionally, run git diff develop... -U0 --no-color | clang-format-diff.py -p1 -i on latest changes and commit