1. A pointing system, comprising: a plurality of reference marks illuminating with an identifiable spectrum; a remote controller comprising: a memory unit configured to previously store different positioning algorithms, each of the different positioning algorithms being associated with a predetermined total number of reference marks, and at least two of the predetermined total numbers associated with the different positioning algorithms being different from one another, and an image sensor configured to capture an image frame containing at least one reference mark image of the reference marks, the remote controller configured to recognize a total number of the at least one reference mark image in the captured image frame, select a first positioning algorithm among the different positioning algorithms when the total number of the at least one reference mark image in the captured image frame is a first number, and output a cursor coordinate calculated by the first positioning algorithm to control a cursor shown on a display screen, and select a second positioning algorithm among the different positioning algorithms when the total number of the at least one reference mark image in the captured image frame is a second number different from the first number, and output a relative displacement of the cursor calculated by the second positioning algorithm to control the cursor on the display screen, wherein the predetermined total number of reference marks associated with the first and second positioning algorithms is related to the total number of the at least one reference mark image in the captured image frame, and wherein the first and second positioning algorithms are configured to respectively output the cursor coordinate and the relative displacement using the at least one reference mark image in the image frame captured by the same image sensor.