[Insight-users] All zero output with ResampleImageFilter (ITK 3.4)

[Luis Ibanez]

Hi Victor,


1) How did you arrive to the conclusion
    that all the output values are zeros ?

    because you see a black image in a visualization tool ?
    or because you actually used a program to check the
    pixel values ?

2) If you set the Similarty Transform to be an Identity,
    do you see an proper image in the output ?


Please let us know,



    Thanks


        Luis


--------------------------------
Víctor Rodrigo Córdoba wrote:
> Hi All.
> 
> I have the following function to register models (modReader) to the size 
> of an active contour (contActivo). Xsize, ysize and zsize are the number 
> of rows, columns and slices of active contour bounding box.
> 
> When I execute it, the output of the Resample filter is all zero. I 
> don't know what I'm doing wrong.
> I need your help.
> 
> typedef signed short PixelType;
> typedef itk::Image< PixelType, 3 > ImageType;
> typedef double FPixelType;
> typedef itk::Image< FPixelType, 3 > FImageType;
> typedef itk::ImageSeriesReader< ImageType > ReaderType;
> 
> ImageType::Pointer adaptarModeloImg4D(ReaderType::Pointer modReader,int 
> xsize,int ysize,int zsize,FImageType::Pointer contActivo)
> {
>     typedef itk::ResampleImageFilter<ImageType,ImageType> ResampleFilter;
>     ResampleFilter::Pointer filResample = ResampleFilter::New();
>     filResample->SetInput(modReader->GetOutput());
>      
>     typedef itk::LinearInterpolateImageFunction<ImageType, double > 
> InterpolatorType;
>     InterpolatorType::Pointer interpolator = InterpolatorType::New();
>     filResample->SetInterpolator(interpolator);
>     filResample->SetDefaultPixelValue(0);
>      
>     const FImageType::SpacingType& spacing = contActivo->GetSpacing();
>     const FImageType::PointType& origin = contActivo->GetOrigin();
>     FImageType::SizeType sizeCA = 
> contActivo->GetLargestPossibleRegion().GetSize();
>     ImageType::SizeType sizeMod = 
> modReader->GetOutput()->GetLargestPossibleRegion().GetSize();
>     filResample->SetOutputOrigin(origin);
>     filResample->SetOutputSpacing(spacing);
>     filResample->SetSize(sizeCA);
> 
>     // Computing scale on rows, columns and slices
>     double scaleX = (double)xsize/(double)sizeMod[1];
>     double scaleY = (double)ysize/(double)sizeMod[0];
>     double scaleZ = (double)zsize/(double)sizeMod[2];
>     
>     // Tanking the minimum scale
>     double scale = scaleX<scaleY ? scaleX:scaleY;
>     scale = scale<scaleZ ? scale:scaleZ;
> 
>     typedef itk::Similarity3DTransform< double > TransformType;
>     TransformType::Pointer transform = TransformType::New();
>     transform->SetScale(scale);
>    
>     // Computing the beginning of the active contour
>     int posY= floor(((double)sizeCA[0]-(double)sizeMod[0]*scale)/2);
>     int posX= floor(((double)sizeCA[1]-(double)sizeMod[1]*scale)/2);
>     int posZ= floor(((double)sizeCA[2]-(double)sizeMod[2]*scale)/2);
>    
>     // Moving model to active contour beginning
>     TransformType::OutputVectorType translation;
>     translation[0] = posY-origin[0];
>     translation[1] = posX-origin[1];
>     translation[2] = posZ-origin[2];
> 
>     // Updating resample filter
>     transform->SetTranslation(translation);
>     filResample->SetTransform(transform);
>     filResample->Update();
> 
>     return filResample->GetOutput();
> }
> 
> Thank you.
> 
> 
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