# input arguments of python's cv2.calibrateCamera

I get the following error when I try to calibrate camera using cv2.calibrateCamera:

```
rms, camera_matrix, dist_coefs, rvecs, tvecs = cv2.calibrateCamera(pts3d, pts2d, self.imgsize, None, None)
cv2.error: /home/sarkar/opencv/opencv/modules/calib3d/src/calibration.cpp:2976: error: (-210) objectPoints should contain vector of vectors of points of type Point3f in function collectCalibrationData
```

I initially had nx3 and nx2 array for pts3d and pts2d. I then tried to reshape pts3d and pts2d in the following form as the function takes vectors of vector point3d (and correspondingly pts2d) as input:

[1 x n x 3] and [1 x n x 2]

[k x n' x 3] and [k x n' x 3], where k is some random value

[1 x n x 1 x 3] and [1 x n x 1 x 2]

nothing works and it always gives the same error.

I saw the code sample code of cameraclibration provided which runs fine, and their input is of [k x n x 3]. I really don't know what is wrong with my implementation. Following is my code to be precise:

```
#data contains [n x 5] dim array which is the hstacked arrays of pts3d and pts2d correspondences I obtained elsewhere.
pts3d = data[:, 0:3] #first 3 column
pts2d = data[:, 3:5] #next 2 column.. I checked the values are coming correctly
pts3d = pts3d.reshape(1,-1, 3) #Here, I have experimented by resizing with different values.
pts2d = pts2d.reshape(1,-1, 2)
rms, camera_matrix, dist_coefs, rvecs, tvecs = cv2.calibrateCamera(pts3d, pts2d, self.imgsize, None, None)
```

the error happens at the time of the function call. It would be nice to know what can be wrong here.