User identification system and method for identifying user

An identification system for identifying a user by receiving a motion trajectory generated by the user, the identification system comprising:

• an image sensor for capturing a plurality of images of the motion trajectory generated by the user in an undefined motion;
• a storage unit for storing motion vector information of a group of users generating the motion trajectory, wherein each of the motion vector information includes an individual pattern of one of the users in the group, the individual pattern including an individual motion and an individual fingerprint of a corresponding user;
• a comparing unit for comparing the plurality of images with the motion vector information to identify the user according to whether the motion trajectory generated by the user in the undefined motion and a motion trajectory previously generated by the user both includes include the individual pattern, so that different users are differentiated according to different individual patterns, wherein the motion trajectory generated by the user in the undefined motion is not the same as the motion trajectory previously generated by the user;
• and
• wherein the individual motion includes distance information and angle information, and wherein the individual pattern is extracted from the motion trajectory previously generated by the user by statistically classifying the distance information and the angle information.