title: C++ Opencv Calibration of the camera with different resolution
body: <p>My camera has different resolutions 
  1280*480
  640*240 
  320*120 </p>
  
  <p>I have used the algorithm of Opencv3 to calibrate the camera with the resolution of 1280*480 and I have got the camera matrix (fx fy cx cy)and the distortion matrix (k1 k2 p1 p2 k3)for this resolution. </p>
  
  <p>But now I want to use these camera matrix and distortion matrix to calibrate the camera with the resolution of 320*120. I don't know how to apply these two matrix of the resolution 1280*480 to the resolution of 320*120.
  PS I haven't calibrated the camera with the resolution of 320*120 directly because the image is too small and the algorithm of Opencv can't find the chessboard.</p>
  
  <p>I want to know how the camera matrix (fx fy cx cy)and the distortion matrix (k1 k2 p1 p2 k3) will change if i change the resolution 1280*480 to 320*120. </p>
  
  <p>The algorithm of opencv is the following one: 
  <a href="http://docs.opencv.org/3.0-beta/doc/tutorials/calib3d/camera_calibration/camera_calibration.html" rel="nofollow noreferrer">http://docs.opencv.org/3.0-beta/doc/tutorials/calib3d/camera_calibration/camera_calibration.html</a>    </p>