[vtkusers] vtkImageMapToWindowLevelColors help

Luca Pamparana luca.pamparana at gmail.com
Tue Apr 17 11:13:05 EDT 2007


Hey ANka,

Maybe my intial attempt at vtkImageMapToWindowLevelColor objects was wrong.

I have a question to you about the look up table. In your code:

m_displayWindowLevelColorsImage->SetInput(m_displayImage->GetOutput());
m_displayWindowLevelColorsImage->SetLookupTable(lut);
m_displayWindowLevelColorsImage->SetWindow(m_win_level[0]*scale);
m_displayWindowLevelColorsImage->SetLevel(m_win_level[1]*scale);

My input data is of type unsigned short and the data intensity values
vary from 1000 to 20000.

Now, I want to present the user with this window and to be able to set
the width of this intensity window.
The filter will change the scalar type to unsigned char. I am
wondering how I should generate this look up
table so that it will cover my data.

Thanks,

Luca

On 4/17/07, Anka Kochanowska <anka at bic.mni.mcgill.ca> wrote:
>
> Ok, here is a part of my real program.
> I would send you the whole class, but cannot do it without my boss'
> approval.
> Anka
>
>     vtkSmartPointer<vtkImageReslice> m_reslice;
> ...
>         m_reslice->SetInput( m_imageData );
>         m_reslice->SetInterpolationModeToLinear( );
>         m_reslice->SetOutputExtent(0, 639, 0, 479, 0, 1);
>         m_reslice->SetOutputOrigin(0, 0, 0);
>         m_reslice->SetOutputDimensionality(2);
>         m_reslice->SetOutputSpacing(1,1,1);
>         m_reslice->SetResliceTransform( concat );
>         m_reslice->UpdateInformation();
>
>         m_displayImage = vtkSmartPointer<vtkImageShiftScale>::New();
>         m_displayImage->SetInput(m_reslice->GetOutput());
>         m_displayImage->SetScale(scale);
>         m_displayImage->SetOutputScalarTypeToUnsignedChar();
>
>         m_displayWindowLevelColorsImage =
> vtkSmartPointer<vtkImageMapToWindowLevelColors>::New();
>
> m_displayWindowLevelColorsImage->SetInput(m_displayImage->GetOutput());
>
>         m_displayWindowLevelColorsImage->SetLookupTable(lut);
>         m_displayWindowLevelColorsImage->SetWindow(m_win_level[0]*scale);
>         m_displayWindowLevelColorsImage->SetLevel(m_win_level[1]*scale);
>
>         m_mriActor->SetInput(m_displayWindowLevelColorsImage->GetOutput());
>         m_mriRenderer->AddViewProp( m_mriActor );
>
>
> m_mriOutlineFilter->SetInput(m_displayWindowLevelColorsImage->GetOutput());
>         m_mriOutlineMapper->SetInput( m_usOutlineFilter->GetOutput() );
>         m_mriRenderer->AddViewProp( m_mriOutlineActor );
>
>
> Luca Pamparana wrote:
>
> > Hey Anka,
> >
> > Thanks again for the reply.
> >
> > The thing is that I am using the reslicer to extract a 2D slice and
> > just display that. All the interpolation, orientation, which slice to
> > extract etc. is controlled by the reslicer.
> >
> > The vtkImageActor seems to have its own corresponding methods for
> > these operations. I am wondering if these can coexist... Only one way
> > to find out, I guess! Time for try some quick hack...
> >
> > Thanks,
> > Luca.
> >
> > On 4/17/07, *Anka Kochanowska* < anka at bic.mni.mcgill.ca
> > <mailto:anka at bic.mni.mcgill.ca>> wrote:
> >
> >     I am using vtkImageActor:
> >
> >
> >             vtkImageActor * mriActor;
> >     ...
> >     ...
> >             blendedImage->AddInput( 0, img1->GetOutput());
> >             blendedImage->AddInput( 0,
> >     .displayWindowLevelColorsImage->GetOutput());
> >             blendedImage->Update();
> >             mriActor->SetInput(blendedImage->GetOutput());
> >             renderer->AddViewProp( mriActor );
> >     Anka
> >
> >     Luca Pamparana wrote:
> >
> >     > Hello everyone,
> >     >
> >     > I am unable to get the vtkImageMapToWindowLevelColors to give me
> an
> >     > output :(
> >     >
> >     > My pipeline is as follows:
> >     >
> >     > // vtkImageData input to a reslicer
> >     > this->m_slicer->SetInput(in);
> >     >
> >     > // pass the output of the slicer to
> >     vtkImageMapToWindowLevelColors object
> >     >
> >
> this->m_windowLevelMapper->SetInputConnection(this->m_slicer->GetOutputPort());
> >     >
> >     >
> >     > // Pipe the output to a vtkImageBlend object
> >     > this->m_blender->AddInputConnection(0,
> >     > this->m_windowLevelMapper->GetOutputPort());
> >     >
> >     > // Pipe output to a vtkImageMapper. This mapper is tied to the
> >     Actor2D
> >     > // object that is added to the renderer
> >     > this->m_imageMapper->SetInput(this->m_blender->GetOutput());
> >     >
> >     > double * range = in->GetScalarRange();
> >     > if (range)
> >     > {
> >     >       // this calls the ciorresponding methods on the
> >     > vtkImageMapToWindowLevelColors object
> >     >        this->SetColorWindow(range[1] - range[0]);
> >     >        this->SetColorLevel(0.5 * (range[1] + range[0]));
> >     >  }
> >     >
> >     > SetSlice(static_cast<int>((GetWholeZMin() + GetWholeZMax()) * 0.5
> ));
> >     >
> >     > My guess is that I am not setting the ColorWindow and ColorLevel
> on
> >     > the vtkImageMapper instance. However, I want to control the color
> >     > window and color level values independently of the mapper as the
> >     > vtkImageBlend will also have other inputs that I want to control
> >     the
> >     > window and level values for.
> >     >
> >     > Any help on how I can get this to work is much appreciated.
> >     >
> >     > Thanks,
> >     > Luca
> >     >
> >
> >------------------------------------------------------------------------
> >
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