Cfrgtkky

I want to use ArUco to find the "space coordinates" of a marker.
I have problems understanding the tvecs and rvecs. I came so far as to the tvecs are the translation and the rvecs are for rotation. But how are they oriented, in which order are they written in the code, or how do I orient them?

Here is a little sketch of the setup. I have a camera (laptop webcam just drawn to illustrate the orientation of the camera) at the position X,Y,Z, the Camera is oriented, which can be described with angle a around X, angle b around Y, angle c around Z (angles in Rad).

So if my camera is stationary I would take different pictures of the ChArUco Boards and give the camera calibration algorithm the tvecs_camerapos (Z,Y,X) and the rvecs_camerapos (c,b,a). I get the cameraMatrix, distCoeffs and tvecs_cameracalib, rvecs_cameracalib. t/rvecs_camerapos and t/rvecs_cameracalib are different which I find weird.

• Is this nomination/order of t/rvecs correct?


• Should I use camerapos or cameracalib for pose estimation if the camera does not move?

I think t/rvecs_cameracalib is negligible because I am only interested in the intrinsic parameters of the camera calibration algorithm.

Now I want to find the X,Y,Z position of the marker, I use aruco.estimatePoseSingleMarkers with t/rvecs_camerapos and retrive t/rvecs_markerpos. The tvecs_markerpos don't match my expected values.

• Do I need a transformation of t/rvecs_markerpos to find X,Y,Z of the Marker?


• Where is my misconception?