Method of acquiring multiple light spot coordinates

The present invention provides a method of acquiring multiple light spot coordinates, which is applied in a light projection system. The system employs a plurality of light emitter to emit light onto the screen to form multiple light spots, and captures the image by a camera, wherein the light emitters can arbitrarily generate an emitting signal. The method includes: capturing a plurality of images by the camera according to the time sequence; respectively determining the capturing time for each light spots in the individual image from the plurality of images captured according to the time sequence; respectively calculating the coordinates of each light spot in the individual image; storing the capturing time and coordinates of each light spot in a database; determining the emitting time when each light emitter generated the emitting signal; and, selecting the light spot having the capturing time closest to the emitting time in the database and acquiring the coordinates of the light spot.