Copy data from cv::Mat to CvMat and viceversa

Question

如何在OpenCV中将数据从cv :: Mat复制到CvMat，反之亦然？

Answer 1

According to the documentation for cv::Mat , cv::Mat has a constructor that takes a CvMat * argument and an operator CvMat() member function. Therefore copying between the two can be accomplished easily as follows.

cv::Mat m;

// populate m

CvMat n = m; // cv::Mat::operator CvMat() const;

m = cv::Mat(&n); // cv::Mat::Mat(const CvMat* m, bool copyData = false);
// or
m = cv::Mat(&n, true); // to copy the data

Answer 2

According to opencv documentation ( http://docs.opencv.org/2.4/modules/core/doc/basic_structures.html ):

"Backward conversion from Mat to CvMat or IplImage is provided via cast operators Mat::operator CvMat() const and Mat::operator IplImage(). The operators do NOT copy the data."