Rotation Matrix in camera calibration.

I am trying to find out camera matrix and other parameters for single camera using calibration app. The rotation matrix i am getting is 3*3*5. What does it means for single camera, as i understand for single camera the world coordinate and camera coordinate is same so the rotation matirx should be a unitary matrix but i am not getting it as a unitary matrix. Please someone clarify.

Answer 1

[Raynier Suresh]

A rotation matrix is a 3-by-3 matrix, the rotation matrix together with the translation vector allows you to transform points from the world coordinate to the camera coordinate system. You are getting a 3x3x5 because you have 5 pattern images. For each pattern image you will get a rotation matrix.

The below links has explained this clearly:

https://www.mathworks.com/help/vision/ref/cameraparameters.html#d118e109373

https://www.mathworks.com/help/releases/R2017a/vision/ref/extrinsics.html#bt9eb6w-5

[Dorian Röders]

I have stumbled upon a similar problem. I have X and Y coordinates from two tracking cameras and I would like to apply the camera calibration parameters to them, to correct for the camera distortion. Now it seems I need the pointsToWorld function for this. This also requieres a 3x3 rotation matrix I also have a 3x3xN matrix. The same goes for the translation vector. How can I get to the matrix I need?

[Dorian Röders]

I solved the problem myself. I tried to use pointsToWorld, but undistortPoints was what I was looking for.

[Jacob Hardy-King]

Hi, I've got the same issue where my rotational matrix is a 3x3xn, and the translational vector is a 1x3xn. I'm looking to get both of these in the correct format to use the function "pointsToWorld" (a (3x3) for rotational matrix and a (1x3) for translational matrix).

At the moment I have been finding the average of the 3x3 across the n images for the rotational matrix, and finding the average of the 1x3 across the n images for the translational matrix. Is this the correct method to do this?

Currently the average rotational matrix that I am calculating is not orthogonal and is producing errors.

Any help would be much appriciated.

[Zeqi Wang]

Hi there, I have exactly the same problem as yours when I am trying to use the StereoParams for rectification. I need to extract the rotation matrix (3x3) and translation vector (1x3) of left camera and right camera to my rectification process, while the Rotation Matrices is 3x3xn and Translation Vectors is 1x3xn here. How did you solve this problem?

So much appreciation in ahead.