[Insight-users] ContourSpatialObject

[Anja Ende]

Hello,

This is my ongoing battle to create a binary image out of a user
defined set of points.

I noticed that there is a spatial object based class called
ContourSpatialObject. I have been trying to use it but it does not
produce any output. I used the following code:

typedef itk::ContourSpatialObject<2>  ContourType;
typedef ContourType::Pointer ContourPointer;
typedef itk::ContourSpatialObjectPoint<2> ContourPointType;

ContourType::ControlPointListType list;
ContourPointType p1;
p1.SetPosition(10, 10);
p1.SetRed(1);
p1.SetGreen(1);
p1.SetBlue(1);
p1.SetNormal(0, 0, 1);
list.push_back(p1);

ContourPointType p2;
p2.SetPosition(20, 10);
p2.SetRed(1);
p2.SetGreen(1);
p2.SetBlue(1);
p2.SetNormal(0, 0, 1);
list.push_back(p2);

ContourPointType p3;
p3.SetPosition(20, 5);
p3.SetRed(1);
p3.SetGreen(1);
p3.SetBlue(1);
p3.SetNormal(0, 0, 1);
list.push_back(p3);

ContourPointType p4;
p4.SetPosition(10, 5);
p4.SetRed(1);
p4.SetGreen(1);
p4.SetBlue(1);
p4.SetNormal(0, 0, 1);
list.push_back(p4);

ContourPointType p5;
p5.SetPosition(10, 10);
p5.SetRed(1);
p5.SetGreen(1);
p5.SetBlue(1);
p5.SetNormal(0, 0, 1);
list.push_back(p5);

ContourPointer contour = ContourType::New();
contour->GetProperty()->SetName("My Blob");
contour->SetId(1);
contour->SetControlPoints(list);

typedef itk::Image<unsigned char, 2> ImageType;
typedef itk::SpatialObjectToImageFilter<ContourType, ImageType>
SpatialObjectToImageFilterType;
typedef SpatialObjectToImageFilterType::Pointer
SpatialObjectToImageFilterTypePointer;

SpatialObjectToImageFilterTypePointer filter =
SpatialObjectToImageFilterType::New();
filter->SetInput(contour);
ImageType::SizeType size;
size[0] = 128;
size[1] = 128;
filter->SetSize(size);
filter->Update();

typedef itk::RescaleIntensityImageFilter<ImageType, ImageType>  CastFilterType;
CastFilterType::Pointer castFilter = CastFilterType::New();
castFilter->SetOutputMinimum( 0 );
castFilter->SetOutputMaximum( 255 );
castFilter->SetInput(filter->GetOutput() );
typedef itk::ImageFileWriter<ImageType> WriterType;
WriterType::Pointer writer = WriterType::New();
writer->SetFileName("/home/anja/Desktop/test.jpg");
writer->SetInput(castFilter->GetOutput());
try
{
        writer->Update();
}

catch( itk::ExceptionObject & err )
{
        std::cout << "Problems" << std::endl;
}

So, I have created 5 points that should be a closed contour and then I
am converting the output of the spatial object to an image using the
itk::SpatialObjectToImageFilter and writing it to a file after
rescaling the values. However, the output is a totally black image. I
tried this technique with the BlobSpatialObject and the output was as
extected. Here, I had extected to see a contour with the area inside
the contour to be all filled with the value of 255.

Any ideas what I might be missing?

Cheers,

Anja