Documentation/4.2/Developers/Tutorials/PortingCLIToITKv4
ITKv4
Links to ITKv4 Links to Migration guide
Known issues in porting CLIs
My filter doesn't run.
The API to ThreadedGenerateData() changed in ITKv4 (use of a defined type ThreadIdType). This can result in your implementation of ThreadedGenerateData() defining a new function instead of overriding the version called by the pipeline. ITKv4 attempts to emit a run-time exception but there are circumstances where the exception cannot be thrown (for instance, if the superclass already provided a valid version of ThreadedGenerateData()). If your filter is not executing in ITKv4, check the declaration of ThreadedGenerateData().
ITKv3 version of ThreadedGenerateData()
virtual void ThreadedGenerateData(const OutputImageRegionType& outputRegionForThread, int threadId );
ITKv4 version of ThreadedGenerateData()
virtual void ThreadedGenerateData(const OutputImageRegionType & outputRegionForThread, ThreadIdType threadId);
DICOM/GDCM
ITKv4 updated the version of GDM used to version 2. GDCM version 2 has many API changes from version 1. If your CLI used GDCM directly, you will need to port your CLI to ITKv4. If you used ITK abstractions to access DICOM, then the changes to GDCM will not affect your CLI.