Add option to skip jacobian calculation for cv2.projectPoints() to speed up calculation about opencv-python

[weidinger-c]

image_points = cv2.projectPoints(..., None)

no unfortunately that does not work. Then I still get an object containing the points (1st array) and the jacobian matrix (2nd array).

[weidinger-c]

https://docs.opencv.org/4.x/d9/d0c/group__calib3d.html#ga1019495a2c8d1743ed5cc23fa0daff8c
The python call always returns a jacobian based on the documenation?
Python:
cv.projectPoints( objectPoints, rvec, tvec, cameraMatrix, distCoeffs[, imagePoints[, jacobian[, aspectRatio]]] ) -> imagePoints, jacobian

[weidinger-c]

@asmorkalov I guess there should be an option to calculate the jacobian or pass the None argument correctly to the C++ implementation?

[asmorkalov]

The statement is not correct. Jacobians output is optional and has NoArray() value by default. In Python, it means that you get function overload without the output at all. Internally the function checks, if output is needed and calculates it on demand only.
See https://github.com/opencv/opencv/blob/c71d4952733a0e1dd1f88ac87066c802f1119d97/modules/calib3d/src/calibration.cpp#L879 and https://github.com/opencv/opencv/blob/c71d4952733a0e1dd1f88ac87066c802f1119d97/modules/calib3d/src/calibration.cpp#L918.

[weidinger-c]

@asmorkalov Thanks for the reply. Could you please tell me how to call the python function correctly then? I have not been able to get a result, that does not contain the jacobian matrix

[asmorkalov]

You can try None as the function parameter as empty OutputArray.

[weidinger-c]

No that does not work ("Expression cannot be assignment target")

[asmorkalov]

image_points = cv2.projectPoints(..., None)