Cv2Rodrigues Method (Double, Double, Double) OpenCvSharp Class Library
converts rotation matrix to rotation vector using Rodrigues transformation

Namespace:  OpenCvSharp.CPlusPlus
Assembly:  OpenCvSharp.CPlusPlus (in OpenCvSharp.CPlusPlus.dll) Version: 1.0.0.0 (1.0.0.0)
Syntax

public static void Rodrigues(
	double[,] matrix,
	out double[] vector,
	out double[,] jacobian
)

Parameters

matrix
Type: SystemDouble
Input rotation matrix (3x3).
vector
Type: SystemDouble
Output rotation vector (3x1).
jacobian
Type: SystemDouble
Optional output Jacobian matrix, 3x9, which is a matrix of partial derivatives of the output array components with respect to the input array components.
See Also

Reference