1. An optical touch display system, comprising: a touch region; a light source, disposed on a periphery of the touch region, the light source positioned at least partially above the touch region, such that light rays emitted from the light source may traverse the touch region; a reflector, disposed on at least a part of the periphery of the touch region, for reflecting the light rays emitted from the light source and generating a mirrored image of a set of touch points; an image sensor, disposed above the light source, for receiving light rays of the light source, reflected from the set of touch points on the touch region and the reflector, and generating a two-dimensional image accordingly; wherein the two-dimensional image comprises a set of optical images, the set of optical images comprising a set of real images corresponding to the set of touch points, and a set of virtual images corresponding to the set of touch points, generated by the light rays from the light source reflected by the reflector; and a processing device, for generating a set of output coordinates corresponding to the set of touch points according to positions of the set of real images and the set of virtual images in the two-dimensional image.