[ITK-users] [ITK] ShapeLabelMap Roundness/Perimeter Calculation Issue

[Lowekamp, Bradley (NIH/NLM/LHC) [C]]

Hello,

You can find additional information about how this parameter is defined in the following insight journal:
http://www.insight-journal.org/browse/publication/852

This method is generalizable to N-D, so it may not be the most accurate in 2D. The method can produce roundness numbers that are >1. However is should be consistent in debug and release modes. Getting consistent numeric computation with C++ and vectorizable operations can be challenging with different architectures.

You did not provide any specifics for the difference in computation between release and debug modes.

HTH,
Brad

> On May 13, 2016, at 11:26 AM, ebasafa <ehsan.basafa at gmail.com> wrote:
> 
> Hi everyone,
> 
> Recently I noticed that BinaryImageToShapeLabelMapFilter does not calculate
> roundness of objects correctly, and I traced it back to perimeter
> calculation. More curiously, the results I get from the GetRoundness() and
> GetPerimeter() methods differ between debug and release builds! And to make
> it even more confusing, it's a machine-dependent problem, i.e. on some
> machines debug and release give the same (correct?) numbers and on some
> machines they don't. I suspect that release results are erroneous, since
> some roundness numbers turn out to be >1.0 in release but are always <1.0 in
> debug mode. I am working in a Windows 8.1 64-bit environment and am using
> the latest release of ITK (4.9.1) on all different machines.
> 
> I have tried several searches to see if this is a resolved issue, but the
> latest post I found was from 2011 (link below) and has been unanswered. 
> 
> http://itk-users.7.n7.nabble.com/Perimeter-Calculation-via-LabelImageToShapeLabelMapFilter-td14917.html
> 
> Seems like there was a bug report filed that time
> (https://itk.org/Bug/view.php?id=11934) whose status still says "assigned".
> I appreciate any help.
> 
> Thanks,
> Ehsan
> 
> 
> 
> 
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