OpenCV Q&A Forum - RSS feedhttp://answers.opencv.org/questions/OpenCV answersenCopyright <a href="http://www.opencv.org">OpenCV foundation</a>, 2012-2018.Mon, 12 Dec 2016 11:22:40 -0600How to I find the distortion coefficients of a camera from a certain height?http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/ I need to find the distortion coefficients of a camera which clicks picture from around 180m above the ground. How do I find the distortion coefficients of my camera when it takes aerial shots from about 180 meters? Please help me out here. Is there a relation between distortion coefficients when taken from a lower height to distortion coefficients when image taken from a higher altitude?Mon, 28 Nov 2016 09:57:48 -0600http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/Answer by Tetragramm for <p>I need to find the distortion coefficients of a camera which clicks picture from around 180m above the ground. How do I find the distortion coefficients of my camera when it takes aerial shots from about 180 meters? Please help me out here. Is there a relation between distortion coefficients when taken from a lower height to distortion coefficients when image taken from a higher altitude?</p>
http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?answer=115158#post-id-115158The distortion coefficients are independent of the scene, assuming you have a constant focal length. All you need to do is calibrate the camera once. Whether that involves a chessboard at some close distance, or whatever, if you calibrate once, you're good for any altitude or scene.Mon, 28 Nov 2016 10:24:23 -0600http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?answer=115158#post-id-115158Comment by Prototype for <p>The distortion coefficients are independent of the scene, assuming you have a constant focal length. All you need to do is calibrate the camera once. Whether that involves a chessboard at some close distance, or whatever, if you calibrate once, you're good for any altitude or scene.</p>
http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=118433#post-id-118433@Tetragramm http://answers.opencv.org/question/118431/camera-callibration-does-not-complete-for-my-set-of-images/ Please help me with this. Also @BerakMon, 12 Dec 2016 11:22:40 -0600http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=118433#post-id-118433Comment by Prototype for <p>The distortion coefficients are independent of the scene, assuming you have a constant focal length. All you need to do is calibrate the camera once. Whether that involves a chessboard at some close distance, or whatever, if you calibrate once, you're good for any altitude or scene.</p>
http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=115175#post-id-115175@Tetragramm Thanks a lot. Are you sure that the distortion coefficients are indepentdent of height? because I was told that it is not and my assignment was to find a way to figure out the distorion coefficients of our camera from that height.Mon, 28 Nov 2016 10:48:15 -0600http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=115175#post-id-115175Comment by Prototype for <p>The distortion coefficients are independent of the scene, assuming you have a constant focal length. All you need to do is calibrate the camera once. Whether that involves a chessboard at some close distance, or whatever, if you calibrate once, you're good for any altitude or scene.</p>
http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=115185#post-id-115185@Tetragramm Thanks a lot.I wil look into it.Mon, 28 Nov 2016 11:00:46 -0600http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=115185#post-id-115185Comment by Tetragramm for <p>The distortion coefficients are independent of the scene, assuming you have a constant focal length. All you need to do is calibrate the camera once. Whether that involves a chessboard at some close distance, or whatever, if you calibrate once, you're good for any altitude or scene.</p>
http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=115180#post-id-115180As long as the focal length doesn't change, yes. The distortion only depends on the lens of the camera. Now, the visual effect each type of distortion has can appear different, but the distortion is constant. [THIS](http://docs.opencv.org/master/d9/d0c/group__calib3d.html) page has a pretty good explanation of the distortion and how it effects the image.Mon, 28 Nov 2016 10:57:25 -0600http://answers.opencv.org/question/115135/how-to-i-find-the-distortion-coefficients-of-a-camera-from-a-certain-height/?comment=115180#post-id-115180