Camera calibration using catenary and accelerometer

A camera is a sensor which projects the real world to the image plane. Estimation of the parameters embedded on the camera via camera calibration enables computation of the angular distance and spatial measurements between the points in the image. A particular object with known dimensions can be used for this purpose. Producing these objects practically with available materials is an advantage. From this point of view, we proposed a novel camera calibration method using only a hanging chain. Under gravity, a hanging chain fits a special curve called catenary and creates a planar area. By using a longer chain, this planar area can be enlarged. Thus the proposed method also solves out-of-focus problem in calibration. The proposed method is as accurate as the widely-used checkerboard in calibration. On the other hand, camera-integrated smart systems like mobile devices have an accelerometer. By using the connection between arbitrary vertical or horizontal structures in the image and the direction of gravity provided by the accelerometer, yet another novel camera calibration method is proposed in the dissertation. Being free from an external calibration object makes the proposed method more practical. The accuracy of the proposed method is superior to the widely-used and also recent methods.