ITK Filter on an array of floats

Question

I want to use ITK to Filter a 3D volume that is in a contiguous float array. I want to apply the Curvature Flow Filter as shown in this example.

I don't know how to interface my float array with ITK and then to get a float array out on the other side. Will it modify the data in place? How does it work?

Here is some code to demonstrate what I am trying to do.

#include "itkCurvatureFlowImageFilter.h"

int main(int argc, char *argv[])
{
    float *my_array; // I have an array I have generated elsewhere
    // This is a 3D volume in order XYZ with these dimensions along each axis
    size_t num_x = 125;
    size_t num_y = 250;
    size_t num_z = 125;
    size_t num_elements = num_x * num_y * num_z;
    float voxel_size = 8e-3; // 8 mm voxels

    constexpr unsigned int Dimension = 3;

    // convert to an itk image
    // itkimage = ???

    using InputPixelType = float;
    using InputImageType = itk::Image<InputPixelType, Dimension>;

    const int numberOfIterations = 10;
    const InputPixelType timeStep = 0.05;


    using FilterType = itk::CurvatureFlowImageFilter<InputImageType, InputImageType>;
    FilterType::Pointer filter = FilterType::New();
    filter->SetInput(itkimage);
    filter->SetNumberOfIterations(numberOfIterations);
    filter->SetTimeStep(timeStep);

    // now I want to put the filter result back in th array
    filter->GetOutput();
    // Is the data modified in place? How can I get a regular float array out??

    return EXIT_SUCCESS;
}

Answer 1

itk::ImportImageFilter is used for the purpose of representing some array as an image. Look at the examples linked in the documentation.

As CurvatureFlowImageFilter derives from InPlaceImageFilter, and both your input and output pixel type are same (float), it can run in-place. But you still need to request that:

itkimage = import...;
...
filter->SetInput(itkimage );
// set other parameters
filter->SetInPlace(true);
filter->Update();
itkimage = filter->GetOutput();