[Insight-users] ContourExtractor2DImageFilter in python

[Gaëtan Lehmann]

Le 3 juil. 09 à 05:51, Rick Giuly a écrit :

>
> Hello All,
>
> I'm trying to get a contour as a list of points from a binary image  
> of a blob. I'm assuming that ContourExtractor2DImageFilter is the  
> easiest way to do this, considering what filters are available in  
> python. extractor.GetOutputs() returns a DataObjectPointer, I'm not  
> sure how to access the individual elements of this in python. Could  
> someone advise?
>
> (I will need to access each of the contours and each of the points  
> in each contour.)
>
> Thanks
>
> -Rick
>
> ----
>
> import itk
>
> ImageType = itk.Image[itk.F, 2]
> ReaderType = itk.ImageFileReader[ImageType]
>
> reader = ReaderType.New(FileName = "data/A.tiff")
> image = reader.GetOutput()
>
> ExtractorType = itk.ContourExtractor2DImageFilter[ImageType]
>
> extractor = ExtractorType.New()
> extractor.SetInput(image)
> extractor.SetContourValue(100.0)
> extractor.Update()
> print extractor.GetNumberOfOutputs()
> print extractor.GetOutputs()
> # how should I access individual contours?

Hi Rick,

I think you should be able to access all the outputs with the expected  
types with

   [extractor.GetOutput(i) for i in  
range(extractor.GetNumberOfOutputs())]

If you are using wrapitk from googlecode, you can also dow cast a  
DataObject to its real type with

   itk.down_cast(obj)

or to a specific type with

   itk.PolyLineParametricPath[2].cast(obj)

Please let me know if it fix your access problem or not.

Gaëtan


-- 
Gaëtan Lehmann
Biologie du Développement et de la Reproduction
INRA de Jouy-en-Josas (France)
tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
http://voxel.jouy.inra.fr  http://www.itk.org
http://www.mandriva.org  http://www.bepo.fr

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