Hi, I want to register the 3D CT image with the 2D image. The IntensityBased2D3DRegistration.cxx needs a pair of 2D orthographic images. And I only have one 2D image. Can I treat this 2D image as a 3D image and register it using Euler3DTransform with a 3D CT image? Or what can I do to register these images and get the six parameters ( translation along x, y , z axes and rotations around x, y , z axes)?
You should not treat the 2D image as a tomographic 3D image, because it isn’t.
Based on the question, I highly recommend that you gain a better understanding of the theory behind 2D/3D (perspective projection image / tomographic image), before working on an implementation. A good place to start is the classical review by Markelj et al., “A review of 3D/2D registration methods for image-guided interventions”, Medical Image Analysis 16(3): 642-661.