# Real-Time 3D Reconstruction Method for Holographic Telepresence
## 1 Introduction  
Telepresence can be defined in several ways. According to [PERSON] (1980) [1], telepresence was defined as remote control tools in reference to teleoperation systems. [PERSON] (1992) [2] has defined telepresence as the experience of feeling a presence by using the communication medium. [PERSON] (1998) [3] understands telepresence as the degree to which a user can feel their existence in a virtual space. In our modern time, telepresence can be defined as a technology that can provide the feeling of being present in another remote location which enables both a remote and a local user to communicate. The goal of telepresence is to create the feeling of being there or physically present with a remote person [4]. It is possible to have telepresence through a natural-sized image of the person, a 3D representation of the user or their environment, or the interaction between the remote user and the local user. A visual sense can be created by several paradigms, including a remote person appearing in a local setting [5, 6], a remote space that appears to be stretched beyond the local surroundings [7, 8], as well as a local user who is immersed in a remote setting [9, 10]. The 3D reconstruction method is significant to produce human representation. Telepresence combined with 3D reconstruction technology has the potential to alleviate many of the limits associated with standard video-based communication, such as limited natural movement in 3D space, situational awareness, gaze direction, and eye contact due to the fixed viewpoint of the remote participant's camera, as supported by [PERSON] et al. [11] which has evaluatedthe comparison between traditional video communication such as Skype with their 3D reconstruction integrated with the telepresence system called Room2 Room. The result findings show that their systems show significant improvement in presence and completion time. [PERSON], [PERSON] et al. [12] also agrees that 3D reconstruction integrates with telepresence and can also offer the potential for remote collaboration, virtual 3D object manipulation, or exploring the remote site. Modern telepresence technologies enable persons in remote areas to virtually meet and interact with one another through the use of realistic 3D user representations. While display technology has evolved, the ability of the display to replicate a 3D environment remains a critical component. People have been working to advance 3D display technology for years, and researchers have gathered and produced a variety of inventions in recent decades, as well as benefiting from technologies that involve the viewing of 3D components, such as 3D telepresence and virtual reality (VR). Holographic projection is regarded as one of the most promising true 3D display technologies in the near future. This technology can also be implemented in many different forms, such as holographic prisms [13], Z-Holograms [14], HMDs [15], and others. This study, however, wants to discard the use of any specialized equipment such as head-mounted displays to enable the remote user to move freely while interacting with the other user. This study shows the initial results of displaying the human 3D reconstruction using the Z-hologram display that incorporates the Pepper's Ghost method to create the illusion as if the reconstructed user appeared as a 3D representation in the real-world environment. As demonstrated in Figure 1, holographic projection technology is based on an illusionary method known as Pepper's Ghost, which was initially utilized in Victorian theatres around London in the 1860s [16]. A brightly lighted figure below the stage, hidden from the public's view, is mirrored in a pane of glass between the performer and the audience. It appears to the audience that the ghost is present on stage. A hologram is a picture of interference and diffraction on the surface of a real 3D object captured on a specific optical film or glass from all point light sources of a projected target item [17].