A Self-Calibration Method of Zooming Camera

In this article we proposed a novel approach to self- calibrate a camera with variable focal length. We show that the estimation of camera’s intrinsic parameters is possible from only two points of an unknown planar scene. The projection of these points by using the projection matrices in two images only permit us to obtain a system of equations according to the camera’s intrinsic parameters . From this system we formulated a nonlinear cost function which its minimization allows us to estimate the camera’s intrinsic parameters in each view. The results on synthetic and real data justify the robustness of our method in term of reliability and convergence

Critical Motion Sequences for the Self-Calibration of Cameras and Stereo Systems with Variable Focal Length

We consider the self-calibration problem for a moving camera whose intrinsic parameters are known except for the focal length which may vary freely across different views. The conditions, under which the determination of the focal length's values for an image sequence is not possible, are derived. These depend only on the camera's motion. We give a complete catalogue of the so-called critical motion sequences. This is then used to derive the critical motion sequences for stereo systems with variable focal lengths. 2002 Published by Elsevier Science B.V

Critical motion sequences for the self-calibration of cameras and stereo systems with variable focal length", BMVC

We consider the self-calibration problem for a moving camera whose intrinsic parameters are known, except the focal length, which may vary freely across different views. The conditions under which the determination of the focal length’s values for an image sequence is not possible, are derived. These depend only on the camera’s motions. We give a complete catalogue of the so-called critical motion sequences. This is then used to derive the critical motion sequences for stereo systems with variable focal lengths.

Camera self-calibration and analysis of singular cases

Master'sMASTER OF ENGINEERIN

Bir krank biyel mekanizmasının ön kalibreli, 2 ticari kamera kullanılarak geliştirilen görüş sistemi vasıtasıyla kinematik analizi.

There are two main objectives of this study. The first objective is to develop a vision system consisting of 2 inexpensive commercial cameras. In general, by self – calibration methods reconstruction of a scene by using uncalibrated images is performed up to a scale only. However, in this thesis reconstruction of a scene is to be performed such that one obtains the actual values of the distances in the scene. For this purpose, it is assumed that the extrinsic parameters of the cameras are known. Therefore, one needs to determine the intrinsic parameters of the cameras only. In order to calculate the intrinsic parameters, two methods, that take advantage of the simplified Kruppa equations and the equal eigenvalue theorem, are used. The results obtained via the two methods are compared with the results obtained by using a calibration pattern. A triangulation process is then performed to calculate several known distances in the scene by using the method that gives better results for the intrinsic parameters. The actual and estimated distances obtained via the vision system are then presented and compared. The second objective of this study is to perform kinematic analysis of a slider crank mechanism by using the developed vision system. The position, velocity and acceleration analyses of the slider crank mechanism are realized by using several markers that are attached on the moving links of the mechanism. The positions of the markers are calculated by using the vision system. This data is then utilized to determine the joint variables, joint velocities and joint accelerations of the slider crank. The results thus obtained via an encoder attached to the input link of the mechanism are compared with the results obtained via the developed vision system. The effects of the locations of the markers and the effects of the number of markers used on the accuracy of the results are also investigated.M.S. - Master of Scienc