[ITK-users] [ITK] Geodesic Active Contour with Shape Guidance Parameters

Wed May 18 12:16:56 EDT 2016

Hi,

Additionally, it may be helpful to look at the source code that is
used to generate the text:

  https://github.com/InsightSoftwareConsortium/ITK/blob/master/Examples/Segmentation/GeodesicActiveContourShapePriorLevelSetImageFilter.cxx

There is also a test in ITK.  Turn on BUILD_EXAMPLES and BUILD_TESTING
in ITK's CMake configuration.  To see the command use to run the test,
execute "ctest" from the ITK build tree with the "-V" flag for verbose
and "-R" to select the test name.

`--> ctest -R GeodesicActiveContourShapePriorCallosumTest -V
[...]
 Start 2489: GeodesicActiveContourShapePriorCallosumTest 2489: Test
command: /home/matt/bin/ITK-Clang-MinSizeRel/bin/itkTestDriver
"--compare" "/home/matt/bin/ITK-Clang-MinSizeRel/ExternalData/Testing/Data/Baseline/Segmentation/GeodesicActiveContourShapePriorCallosumTest.png"
"/home/matt/bin/ITK-Clang-MinSizeRel/Testing/Temporary/GeodesicActiveContourShapePriorCallosumTest.png"
"/home/matt/bin/ITK-Clang-MinSizeRel/bin/GeodesicActiveContourShapePriorLevelSetImageFilter"
"/home/matt/src/ITK/Examples/Data/BrainMidSagittalSlice.png"
"/home/matt/bin/ITK-Clang-MinSizeRel/Testing/Temporary/GeodesicActiveContourShapePriorCallosumTest.png"
"120" "85" "60" "102" "88" "83" "6" "1.0" "0.5" "0.02"
"/home/matt/src/ITK/Examples/Data/CorpusCallosumMeanShape.mha" "3"
"/home/matt/src/ITK/Examples/Data/CorpusCallosumMode%d.mha" "10" "0"
 2489: Test timeout computed to be: 1500
 2489: 1: 0.045812 [-0.035055221959695966, -0.09800734065323966,
0.04907730547869208, 0.005318973983536123, 10.86828403407632,
1.004596337951197] 2489: 2: 0.042193 [-0.059140664486747936,
-0.08336078625977526, 0.04435292989759791, 0.004098441654243041,
10.432127400031401, 0.4590531607561731] 2489: 3: 0.0404411
[-0.07105401413026971, -0.06988223639208144, 0.06116857571760887,
0.0014592130990724208, 11.267062616976325, 0.57187964997921] 2489: 4:
0.0387712 [-0.07105401413026971, -0.06988223639208144,
0.06116857571760887, 0.0014592130990724208, 11.267062616976325,
0.57187964997921]
[...]

HTH,
Matt

On Wed, May 18, 2016 at 11:40 AM, Timothee Evain
<tevain at telecom-paristech.fr> wrote:
> Hello,
>
> Quote from the ITK book right beside the code snippet that troubles you (at least in my book version, i.e. 4.5):
> "Before starting the segmentation process we need to also supply the initial best-fit shape estimate.
> In this example, we start with the unrotated mean shape with the initial x- and y- translation
> specified through command-line arguments."
>
> So startx and starty are the initial translation (of shape model) parameters that are given as the optimizer initialization.
> The other parameters are the rotation and the principal component multipliers as explained earlier in the example.
>
> About the influence, it highly depends on the scale parameters.
> If you gave them a high scale value relative to others, they are likely to stay stable during the optimization.
>
> HTH,
>
> Tim
>
>
> ----- Mail original -----
> De: "Robert" <scorpiuni at gmail.com>
> À: insight-users at itk.org
> Envoyé: Mercredi 18 Mai 2016 15:38:44
> Objet: [ITK] [ITK-users] Geodesic Active Contour with Shape Guidance    Parameters
>
> Hello,
> I was trying out the Geodesic Active Contour with Shape Guidance example
> from the ITK book, but I can't get the same result as described in the book.
> There is a parameter called "startx" and "starty" that you need to provide.
> This isn't explained in the text. How do I need to choose those parameters,
> and what do they mean/influence? I tried a few different ones, but I don't
> see any influence, however my "final parameters" result is different than in
> the book. Also, my output image looks wrong in the sense that it is not
> rotated at all, it does not seem to find the right spot in the image....
> Could anyone explain those parameters to me?
>
>
>
>
> --
> View this message in context: http://itk-insight-users.2283740.n2.nabble.com/Geodesic-Active-Contour-with-Shape-Guidance-Parameters-tp7588865.html
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