In this paper, we propose a block-based video registration method that can be used for various applications such as objective video quality assessment. Instead of using the entire frames of a reference video sequence and a processed video sequence, we use a limited number of frames which are selected under a certain criterion and the selected frames are divided into a number of sub-blocks. Then, we select a small number of sub-blocks which have large spatial gradients. In order to find such sub-blocks, a spatial filtering is applied to the sub-blocks of the selected frames and we use energy of filtered sub-blocks to measure spatial gradient. The proposed registration method is fast and experimental results show that the method provides accurate registrations for a wide range of videos.