Multimedia: Augmented reality Number: Lecturer: Introduction Multimedia is a new technology that is used in multimedia. This isthe field and the technology that the author will deal with in this paper. The definition of Augmented Reality (AR) has been varied. Some define it as the user displays which are mounted on the head. This definition, however, limits AR to some specific technologies. The definition which can be taken which has no limits combines three features which include the ideas of real and virtual, interactive when it is in real time, and the fact that when it is in 3-D it is registered. This approach in definition is more accepted as opposed to the first definition as it includes other technologies like 2-D overlays. There are some application areas where the use of both 2-D and 3-D has been seen. One example is in the film “Jurassic Park” where the objects are photorealistic and mixed with real environment in 3-D but it is surprising because it is not interactive (Caudell, &. Mizell 543). A major decision that will be required when building AR system is whether one will use video or optics to combine virtual and reality. Each of the options has their own advantages and disadvantages. The device that is used to combine the real and virtual is called see-through HMD. By normal standards, closed-view HMDs will not allow the view of the real world directly. This is not the case with see-through HMDs where it is possible to have a view on the world directly. When this is the case, the virtual objects are superimposed by either optical or video technologies. The diagrams below show how the combination is done by the two technologies, optical and video technologies. Figure 1: Optical see-through HMD Figure 2: Video see-through HMD History of AR Augmented reality started with a scientist called Morton Helig in the 1957. His work started with creating a machine that was called Sensorama. This machine had a design that was to model that of a cinematic experience such that it was to take in all the senses. This machine was able to blow wind at someone, was able to cause vibrations in the seat that someone sat on, and also was able to play sounds right before the eyes of people staring at them! Although it was expected that the construction would sell commercially, this was not so. This was because it was still not easy for the cameraman who was to have three cameras strapped around him/her all the time (Baum et al., 2006). In 2008, Augmented Reality found their way to smart phones where people can enjoy the experience of getting close to somewhere even though they are far from that place using the smart phones. Why we need AR There are many applications that have come with augmented reality. It has found its application in the medical field where doctors and nurses use this technology in surgery. With AR, doctors are now able to collect datasets for patients while they are in real time. The datasets that are collected can then be combined in real time with a view of the real patient. What this will mean is that the doctor will have a vision of the X-ray inside a patient using this technology. They will then avoid any hazardous happenings that might happen in the real time. The AR technology is also useful for general application in the surgical room. With this technology, surgeons are able to some features using the naked eye. this is not possible with MRI or CT scans and vice versa. The technology is in a position to give access to both data to the surgeons simultaneously (Caudell, &. Mizell, 2004). Another application of AR technology is in the manufacture and repair of complex machines. It has helped to get the visualizations of the insides of the complex machines that are constructed every day. It has helped to understand complex machines rather than relying on theory alone. With this technology, engineers are now able to get 3-D images on the work they are working on. The technology is also used in aircraft engineering where helicopters use Head-Up Displays (HUDs) and Helmet-Mounted Sights (HMS). This has been simplified with the use of this technology. The technology is also very useful in the entertainment world where the many exhibitors show virtual sets that will be used to merge real actors with backgrounds which are not real and also which are in 3-D. What will happen is that the actors will stand in front of a screen which is blue in color while a camera which is controlled by a computer will be used to record the scene. Previous version of AR Initially, AR was used in stationary systems. They were performed in closed rooms. Today, things are changing really fast as the applications are found on the fly. With wearable computing, the applications of AR are varied. With the developments that are seen currently, engineers are seen to be keen on coming up with mobile applications. The previous applications dealt with applications of AR in the stationary nature. The machines and cameras were stationary as they were associated with stationary desktop computers. This is no longer the case as new emerging trends advocate for applying the AR technology in the field and not confined in one place alone (Uenohara, &. Kanade, 2004). References Baum, W, Ettinger, G, White, S, Lozano-Perez, T, Wells, W, &. Kikinis, R 2006, “An automatic registration method for frameless stereotaxy, image guided surgery, and enhanced reality visualization”, IEEE Journal, Vol 15, Issue 2, Pg 129-140. Caudell, T, &. Mizell, D 2004, “Introduction to augmented reality”, IEEE Journal, Vol 23, issue 4, Pg 533-647. Uenohara, M, &. Kanade, T 2004, Vision-based object registration for real-time image overlay, Carnegie Mellon University.