Opencv getOptimalNewCameraMatrix Vs pinhole projection in pinhole.hpp

[VeeranjaneyuluToka]

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If the issue is about build errors:

• [ x] I have read installation instructions
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• [ x] I have read data collection instructions
• [ x] I have confirmed the program works on example data

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• [ x] I have read the paper

Describe the bug
I am using opencv getOptimalNewCameraMatrix to get undistorted intrinsics but projection is not correct with that compare to pinhole projection that is implemented in pinhole.hpp. Wondering what is the difference between these two approaches.