[Insight-users] Recommended method for setting threads for optimized registration

[Sean Ziegeler]

When building 3.20.0 with ITK_USE_OPTIMIZED_REGISTRATION_METHODS on, I'm 
trying to figure out the latest recommended method for setting the 
number of threads for the entire registration process.

There are a number of examples from the Testing/Code/Review directory, 
and each does it differently, i.e.,

1. itkOptImageToImageMetricsTest uses:
     itk::MultiThreader::SetGlobalDefaultNumberOfThreads(#);
     itk::MultiThreader::SetGlobalMaximumNumberOfThreads(#);

2. itkOptImageToImageMetricsTest2 uses:
     metric->GetThreader()->SetGlobalDefaultNumberOfThreads(#);
     metric->GetThreader()->SetGlobalMaximumNumberOfThreads(#);

3. itkOptMattesMutualInformationImageToImageMetricThreadsTest1 uses:
     metric->SetNumberOfThreads(#);

Is any one better or more recent than the other?

Thanks,
Sean