[Insight-users] Problems with ImageMaskSpatialObject

[Markus Mehrwald]

Hi,
I just implemented some code which uses a ImageMaskSpatialObject. I 
created a binary image in my filter chain and want this now to be a 
spatial object so I use the SetImage method of the spatial object but 
nothing happens. The output of the object looks good. Coordinates (, 
...) are correct but at every point of the so created object ValueAt 
gives me 0. The code looks like the following:

thresholder->Update();
ImageMaskSpatialObjectType::PointType point;
imageMaskSpatialObject = ImageMaskSpatialObjectType::New();
imageMaskSpatialObject->SetImage(thresholder->GetOutput());
imageMaskSpatialObject->SetRequestedRegion(thresholder->GetOutput()->GetRequestedRegion()); 

imageMaskSpatialObject->Update();
imageMaskSpatialObject->UpdateOutputInformation();
imageMaskSpatialObject->ComputeObjectToWorldTransform();
double ret;
for (int i = 0; i < 640; i++)
{
    for (int j = 0; j < 512; j++)
    {
        point[0] = i;
        point[1] = j;
        imageMaskSpatialObject->ValueAt(point, ret);
        if (ret != 0)
            std::cout << "ret: " << ret << std::endl;
    }
}


The image coming from the thresholder has indeed a size of 300x280 but 
changing the for-loops has no consequence on the outcome.
I took a look at the image coming from the thresholder and it is what it 
should be, a binary image with white areas too. The code above never 
writes anything to the standard output because it does not find any 
values differing to 0.
Did I anything wrong or is it a problem of the ImageMaskSpatialObject?

Thanks in advance,
Markus