What does Rvec and Tvec of aruco markers correspond to?

asked 2018-08-10 11:59:58 -0500

changh95 gravatar image

Hi all,

I'm currently doing a project using ArUco marker tracking.

I'm just a bit confused what the rvec and the tvecs are supposed to be. According to the official document, it's supposed to be the rotational vectors and the translational vectors that represents the camera coordinate position relative to the aruco marker's xyz coordinate.

But one thing I discovered today is the following: First, I placed a calibrated camera looking straight down onto the aruco marker. I then moved the aruco marker towards its positive x direction. Theoretically, if the rvecs and the tvecs are representing the 'camera position' relative to the aruco frame, then the act of moving the marker in its positive x-direction should mean 'moving the camera to the negative x-direction' relatively. However, the tvec data shows that the x component has increased.

So I'm confused, if the rvec/tvecs are supposed to be the vectors for 'camera pose estimation' as the document states, or it is actually for 'marker pose estimation'.

Thanks all, please share your opinions on this.

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Comments

rvec and tvec are the rotation and translation vector that transforms a 3D point expressed in the ArUco marker frame into the camera frame. If you want to interpret tvec, it is in the camera frame you have to do it.

Eduardo gravatar imageEduardo ( 2018-08-11 07:34:21 -0500 )edit

@Eduardo So it's marker pose estimation relative to the camera frame?

changh95 gravatar imagechangh95 ( 2018-08-11 11:17:32 -0500 )edit