OpenCV CV::Mat and Eigen::Matrix

Question

Is there a reversible way to convert an OpenCV cv::Mat object to an Eigen::Matrix?

e.g., Some way of doing:

cv::Mat cvMat;
         


        

Answer 1

You should consider using Eigen::Map to wrap OpenCV matrices in order to be used directly by the Eigen SDK. This allows you to apply almost all functionalities implemented in Eigen on matrix allocated by OpenCV

In particular you simply instantiate an Eigen::Map providing the pointer to the cv::Mat buffer:

//allocate memory for a 4x4 float matrix
cv::Mat cvT(4,4,CV_32FC1); 

//directly use the buffer allocated by OpenCV
Eigen::Map eigenT( cvT.data() ); 

for more information on Eigen::Map take a look at Eigen Tutorial: Map Class