1. An optical pointing system comprising: at least one reference beacon; an image sensor configured to capture an image frame containing a beacon image associated with the at least one reference beacon; a storage unit configured to save image data of at least one object image in the image frame; and a processing unit configured to sequentially process every pixel of the image frame within a scan period for identifying the at least one object image, and when a current object image is identified within the scan period and a previous object image exists in the image frame, calculate an image distance between the current object image and the previous object image to accordingly release a part of the image data associated with the at least one object image.