Camera Calibration of a Depth Camera For a regular RGB camera, reading the wikipedia page for camera resectioning/calibration here, they divide the paramters into two categories:
Intrinsic: - focal length, scale factors in x and y, and principal point
Extrinsic: - the rigid body transform of the camera relative to some origin point
My question is how does camera calibration for a depth camera relate to these parameters, for example a Kinect v2 depth camera.
Edit: For example in the SUN RGB-D dataset, there are two files associated with each png image/ png depth image pair. An intrinsic file, and an extrinsic file.
The intrinsic file is a 3 by 3 matrix, example:
529.500000 0.000000 365.000000
0.000000 529.500000 265.000000
0.000000 0.000000 1.000000
From what I understand, using 1-indexing, entry (1,1) and (2,2) according to the camera resectioning article on wikipedia are the focal length multiplied by scale factors relating &quot;pixels to distance&quot; (any elaboration on this appreciated). Whereas entries (1,3), (2,3) represent the coordinates of a principal point. Is this principal point in 2-D or 3D space and what do these numbers mean?
The extrinsics file/s (for some reason there are multiple files sometimes) are
a 4 by 4 matrix, example:
0.979445 0.201365 0.011827 0.000000
-0.201365 0.972640 0.115861 0.000000
0.011827 -0.115861 0.993195 0.000000
Which is a rigid body transform.
Pretty much the same.
The intrinsic calibration tells you the relationship between stuff &quot;out there&quot; relative to the camera's frame of reference and the image the camera makes.  The extrinsic calibration tells you how to get from the camera's frame of reference to whatever your &quot;global&quot; frame of reference may be.