Segmentation Fault style error during Casting

Algorithms
1

Hi there

I’m debugging some code to perform a process on 3D MRI data and I’m getting hung up on a crash I keep encountering when my application is performing a type cast from an unsigned short image to a float.

The relevant snippet of code is as follows:
indent preformatted text by 4 spaces
typedef unsigned short InputPixelType;
typedef float OutputPixelType;

const unsigned int dims = 3;

typedef itk::Image<InputPixelType, dims> InputImageType;
typedef itk::Image<OutputPixelType, dims> OutputImageType;

// Import the image data from pointer
typedef itk::ImportImageFilter<InputPixelType, dims> ImportFilterType;
ImportFilterType::Pointer importFilter = ImportFilterType::New();

// Set up region, spacing, origin, direction etc… (not included to save space)

// m_pSrc is an unsigned short pointer to image data
// m_size is the size (in pixels) of the image dataset
const bool LetImageContainerManageMemory = true;
importFilter->SetImportPointer(m_pSrc,m_size, LetImageContainerManageMemory);

importFilter->Update();

// Now cast the image
typedef itk::CastImageFilter<InputImageType, OutputImageType> CastFilterType;
CastFilterType::Pointer castFilter = CastFilterType::New();
castFilter->SetInput(importFilter->GetOutput());
castFilter->Update();

 indent preformatted text by 4 spaces

Upon calling castFilter->Update(), I get a crash which looks like a segmentation fault type of crash. (in reality, I have the Update() call in a try-catch block); does anyone have any suggestions as to why this may be occurring? Are there extra steps I can take to ensure the cast performs safely?

This may be relevant but this algorithm is being performed in a separate thread; I don’t know how well ITK calls handle being placed into worker threads.

Thank you!

2

Hi @WillScottJackson,

I don’t see any definition of ImagePixelType in your snippet. Maybe you rather wanted to put OutputPixelType?

Tim

3

Ah yes, thank you! Have edited accordingly!

4

Is the caught error of type ExceptionObject ? If so, what does it say ?

1 Like
5

It doesn’t catch any error. Instead I get hard crash with no information being printed to my console.

try {
castFilter->Update();
} catch (itk::ExceptionObject & err) {
std::cout << “ExceptionObject Caught!” << std::endl;
std::cout << err << std::endl;
return false;
}

It leaves me to suspect something goes wrong inside Update() which kills the application rather than any error handling catching it and reporting it back to my exception handler.

6

Which version of ITK are you using? Some stable release or a recent master version? Have you tried stepping through it with a debugger to see where the error is happening?

7

It is fairly old, version 4.7 is the one I’m working with.

I’m not having the easiest time debugging as the function I’m working with is being built into a .dll file and running through a GUI front end.

(I’m debugging an existing code base rather than writing it myself from scratch, hence the awkward set up)

8

I’ve even done some couts just to see what happens:

std::cout << "Type Cast Set up" << std::endl;

try {
	castFilter->Update();
} catch (itk::ExceptionObject & err) {
	std::cout << "ExceptionObject Caught!" << std::endl;
	std::cout << err << std::endl;
	return false;
}

std::cout << "Type Cast Successful" << std::endl;

And the console returns this:
Type Cast Set up
The program ‘[5644] TestViewer.vshost.exe: Managed’ has exited with code -529697949 (0xe06d7363).

As the test application has crashed and has to close.

9

Is the error can be caught at all with:
try
{ castFilter->Update() }
catch (…)
{ std::cout<<“Something was caught” }
?

If so, the error should be trackable in the code. But anyhow I don’t know if you can do so without access to debugging.

10

I managed to catch the exception, I got thrown:
Access Violation - no RTTI Data!

Although the standard itk::ExceptionObject didn’t work.

11

Perhaps you have multiple versions of ITK on your system? This could be a sign that you are including one version but linking ( runtime or compile ) to another.

1 Like
12

I’ve been crawling over my Visual Studio set up. As far as I can tell, everything is correctly referenced. I am building with 4.7 libraries and am linking with 4.7 libraries. The only thing I can think of at the moment is maybe the initial build had some options unchecked when building with CMake.