Image Resolution is the most important quality factor of videos and images. Multi-frame Super-resolution (SR) is the process of creating a higher resolution image with finer details, by using the information of multiple low-resolution images taken from almost the same scene. In recent years images with higher resolution became the most primary requirement in many of the image processing applications, such as scientific applications, medical imaging, robotics, video sequences and satellite imaging. This book aimed at providing a good guide in analyzing the most appropriate multi-frame super-resolution methods based on spatial and frequency domain. It also presents an optimized method which can be used for many image enhancement applications.