Fisheye lens forms a circular image on the image plane which is different from people’s perspective view. This paper introduces two practical methods to correct the fisheye image from distortion. Distorted images can be corrected to the perspective views which are suitable for people to watch by rectilinear projection based on lens functions. This paper extended this method so that it can correct images taken by fisheye lens over 180°. Since the rectilinear projection method has the limitation that it can only correct a ROI, the second method based on an improved cylinder projection is proposed to overcome this limitation. The picture corrected by this method has less deformation compared with traditional cylinder projection method.