Hi I have written a ROS node that implements a camera calibration given intrinsic parameters and a chessboard pattern. I want to use FindExtrinsicCameraParams2, and it would be nice to have a templated cv:: function for it, but I cannot find one anywhere in my environment. Is the ROS version of OpenCV missing any C++ functionality versus OpenCV2.1? So, I resorted to trying to convert the cv::Mat objects I have to CvMat objects using the simple operator. I assume, since there is no data copying, that the matrix header is the only change made. I also assume that I can use the cvFindExtrinsicCameraParams2 function with my newly-created CvMat objects. I run into an error, however, since I cannot directly copy-paste my code so here's a quick rundown. // I have a populated STL vector of Mats vector distortion_coeffs; //I create cv::Mats Mat distortion(rows,cols,CV_64FC3); //Then, populate all of them except tvec,rvec distortion_coeffs[0].copyTo(distortion); //Then copy to the old CvMat struct CvMat distortion_old = distortion; // Then call cvFindExtrinsicCameraParams2 OpenCV Error: Incorrect size of input array (Either the number of channels or columns or rows must be =1) in cvConvertPointsHomogeneous, file /opt/ros/boxturtle/stacks/vision_opencv/opencv2/build/opencv-svn/src/cv/cvfundam.cpp I am running boxturtle on Ubuntu Karmic 2.6.31-14. Thanks for any help. -- Phil Osteen BS Aerospace Engineering, University of Florida MS Mechanical Engineering, University of Florida Research Assistant, Center for Intelligent Machines and Robotics (UF) Researcher, Grupo de Sistemas y Automatica, Universidad de Sevilla Robotics Research Engineer, Motile Robotics Inc