Virtual walk through can be widely applied in many industries such as virtual environment construction, history heritage conservation and scenic site exhibition etc. This paper proposes a more convenient and efficient approach to create realistic virtual walk through from catadioptric omni-directional images via view synthesis technique. Our innovation mainly lies in three aspects: omni-directional image preprocessing, image rectification and novel view interpolation. Acquisition and unwarping of omni-directional image are discussed firstly. Then, for specialty of cylindrical panoramic imaging, epiline-sampling method is adopted for rectification, which samples reference images along epilines as much as possible grounding on epipolar geometry. In this way, it can detract the rectified images from image deformation and resolution degeneration, which usually take place due to perspective transformation when using some other algorithms. As to novel view generation, a corresponding interpolation algorithm is developed. Pixels on novel view are formulated according to the cylindrical panoramic imaging model. Experiments carried out on both synthetic and real scene are given at the end of this paper, with a demonstration of the method's application in realistic virtual walk through.