1. A three-dimensional (3D) teleconferencing apparatus enabling eye contact, comprising: an image acquisition unit for acquiring depth images and color images by manipulating cameras in real time in consideration of images obtained by capturing a subject that is a teleconference participant and images received over a network and corresponding to a counterpart involved in the teleconference; a full face generation unit for generating a final depth image and a final color image corresponding to a full face of the participant for eye contact using the depth images and the color images; a 3D image generation unit for generating a 3D image corresponding to the counterpart and displaying the 3D image on a display device; wherein the image acquisition unit manipulates the cameras in real time by means of a pan operation of horizontally rotating the individual cameras in left/right directions, a tilt operation of vertically rotating the individual cameras in up/down directions, and a height operation of vertically moving the individual cameras in up/down directions; and wherein the image acquisition unit is configured to: perform the pan operation of the cameras based on the captured images, perform the tilt operation of the cameras using both the captured images and the images of the counterpart, and perform the height operation of the cameras based on the images of the counterpart; and wherein the image acquisition unit is configured to: perform the an operation of the cameras based on positions of eyes of the participant detected from the captured images, perform the tilt operation of the cameras based on a difference between the positions of the eyes of the participant and positions of eyes of the counterpart detected in the images of the counterpart, and perform the height operation of the cameras based on an eye level of the counterpart.