[vtkusers] How to convert vtkImageCast back to vtkImageData

[David Gobbi]

Hi Quental,

The solution is as follows:

    cast.Update()
    implicit_volume.SetVolume(cast.GetOutput())

The VTK pipeline recognizes two very distinct kinds of objects:

The vtkImageCast object is a vtk "algorithm" object (derived from
vtkAlgorithm).
The vtkImageData object is a vtk "data" object (derived from vtkDataObject).

An algorithm can never be data.  An algorithm _operates_ on data.
So the algorithm's input is data, and its output is data.

 - David


On Sat, Jun 13, 2015 at 6:36 AM, Quentan Qi <quentan at gmail.com> wrote:

> Hi there,
>
> After casting an image using vtkImageCast, it becomes a vtkImageCast
> object, but I want to use vtkImplicitVolume which requires vtkImageData
> type. How to convert vtkImageCast back to vtkImageData?
>
> ```Python
>
> reader = read_DICOM(path_dicom)  # result is a vtkImageData
>
> cast = vtk.vtkImageCast()
> cast.SetInputData(reader)  # vtkImageData —> vtkImageCast
> cast.SetOutputScalarTypeToShort()  # I need this type
>
> implicit_volume = vtk.vtkImplicitVolume()
> implicit_volume.SetVolume(reader)  # It works but I need “cast” instead
> # implicit_volume.SetVolume(cast)  # It’s wrong because vtkImageData is
> required, but a vtkImageCast was given
> # other things
>
> ```
>
> Thanks a lot!
>
> Cheers,
> Quentan
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20150613/a3ffb821/attachment.html>