title: Undistort image from given calibration data in OpenCV C++
body: <p>I have an image as <code>Foam_Image.jpg</code>, from which I want to remove the fisheye distortion. I already have the camera calibration data within my <code>calibration_data.xml</code> file. I am really a newbie in C++ and I've heard about the  <code>undistort</code> function, but I don't know how can I apply it in OpenCV C++. Could anyone give me an idea?   </p>