How to apply an initial transformation

[bercowsky]

I am trying to register 2 images using rigid registration, but I want to apply an initial transformation before hand. I saw there is the -t0 option in the command line, but is there a way to inform elastix about this transformation in C++?

[N-Dekker]

Thanks for your question, @bercowsky Do you use the ElastixRegistrationMethod? If so, you may call its SetInitialTransform member function, and specify the initial transform as argument:

elastix/Core/Main/itkElastixRegistrationMethod.h

Lines 218 to 220 in fa93025

	/** Set the initial transformation by means of an ITK Transform. */
	void
	SetInitialTransform(const TransformType *);

[bercowsky]

Thanks for your reply! I am trying to register the images using ELASTIX::RegisterImages as shown in the code below, but I have not found an easy way to apply the initial transformation from my code.

elastix->RegisterImages(
        static_cast<typename itk::DataObject::Pointer>(_FixITKImage),
        static_cast<typename itk::DataObject::Pointer>(_MovingITKImage),
        parameters, // Parameter map read in previous code
        _OutputDir, // Directory where output transform params are written, if
                    // enabled
        elastixLogs, // Enable/disable writing of elastix.log
        masking
            ? static_cast<typename itk::DataObject::Pointer>(_FixITKMaskImage)
            : nullptr, // Provide fixed image mask (optional, 0 = no mask)
        nullptr // Provide moving image mask (optional, 0 = no mask)
    );