How is 3D multi-modal medical image registration using mutual information implemented in MATLAB?

Hi,

I want to see the implementation of mutual information based 3D multi-modal medical image registration in MATLAB. While step-running through the imregister function, I have found that it calls a function named imregtform, where the required transformation is computed. Specifically, in imregtform, there is a call to images.internal.builtins.reg, which outputs the transformation. However, I cannot access images.internal.builtins.reg.

Is there a way by which I can access the code written in images.internal.builtins.reg? I need the following information from the code:

1. How is difference in size of the two images handled in the code?
2. How is difference in resolution of the two images handled in the code?
3. How is difference in Region of Interest (ROI) handled in the code?

Answer 1

[Hari]

Hi Debapriya Sengupta,

I understand that you are interested in the implementation details of the MATLAB function "imregtform", specifically regarding how it handles differences in size, resolution, and Region of Interest (ROI) between two images during mutual information-based 3D multi-modal medical image registration. You have found that "imregtform" calls an internal function "images.internal.builtins.reg".

As "images.internal.builtins.reg" is an internal function, the code is not accessible to end-users because it is proprietary and part of the closed-source portion of MATLAB. However, you can refer to the documentation for insights into function capabilities and usage.

• imregtform Documentation - https://www.mathworks.com/help/images/ref/imregtform.html

Hope this helps!