[Insight-users] elongation implementation not matching its definition

[Matt McCormick]

Hi Cagatay,

Thank you for the contribution.  It has been merged, and it will show
up in tomorrows generated Doxygen documentation.

Thanks,
Matt

On Fri, Aug 23, 2013 at 6:45 PM, Cagatay Bilgin <bilgincc at gmail.com> wrote:
> I just corrected this and submitted for review. Thank you for the help.
>
> Cheers,
> C. Cagatay Bilgin
>
>
> On Thu, Aug 22, 2013 at 3:08 PM, Bradley Lowekamp <blowekamp at mail.nih.gov>
> wrote:
>>
>> I agree this is a documentation error. Wikipedia seems to agree with the
>> source code:
>>
>>
>> http://en.wikipedia.org/wiki/Shape_factor_(image_analysis_and_microscopy)#Elongation_shape_factor
>>
>> On Aug 22, 2013, at 5:13 PM, Cagatay Bilgin <bilgincc at gmail.com> wrote:
>>
>> Hello everyone,
>>
>> Either I am missing something or the write up about the elongation is not
>> matching the actual implementation.
>>
>> "elongation is computed as the ratio of the largest principal moment by
>> the smallest principal moment. "
>>
>> however in itkShapeLabelMapFilter.hxx elongation is defined as largest
>> principal moment / second largest principal moment. In 3D the definition and
>> the implementation becomes inconsistent.
>>
>> from itkShapeLabelMapFilter.hxx
>> 331  elongation = vcl_sqrt(principalMoments[ImageDimension - 1] /
>> principalMoments[ImageDimension - 2]);
>> 332  flatness = vcl_sqrt(principalMoments[1] / principalMoments[0]);
>>
>> Cheers,
>> C. Cagatay Bilgin
>>
>> --
>> Cemal Cagatay Bilgin, PhD
>> Life Sciences Division
>> Lawrence Berkeley National Lab
>> MS977, One Cyclotron Road
>> Berkeley, CA 94720, USA
>> Email: ccbilgin at lbl.gov
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>
>
>
> --
> Cemal Cagatay Bilgin, PhD
> Life Sciences Division
> Lawrence Berkeley National Lab
> MS977, One Cyclotron Road
> Berkeley, CA 94720, USA
> Email: ccbilgin at lbl.gov
>
> _____________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Kitware offers ITK Training Courses, for more information visit:
> http://www.kitware.com/products/protraining.php
>
> Please keep messages on-topic and check the ITK FAQ at:
> http://www.itk.org/Wiki/ITK_FAQ
>
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