Image registration, an important preprocess in image fusion, is the process of geometrically aligning two or more images. The image registration can be applied for fusion of medical images, satellite images or images obtained by different sensors at the same time or by same sensor at different times. Image registration involves selection of a control point, which can be done manually or automatically. Manual selection of control point, though simple, is time consuming and can be inaccurate. Automatic image registration does not involve human intervention and many algorithms are available in the literature. Though one algorithm cannot be applied to all applications, algorithms should not be very much application specific. In this paper we study different methods for image registration of different types of images.