Augmented reality or AR is a computer process where the computer displays add virtual information to a user’s sensory perception. Put simply, AR is something that is between the real world and the virtual world and superimposes virtual objects over real-world objects in real-time.
Augmented reality applications require the right information in the right place at the right time. Any delay in any of these creates a negative impact on the overall experience of the system.
Combining direct view, stereoscopic videos and stereoscopic graphics augmented reality describes that class of displays that consists primarily of a real-world environment, with graphics enhancement or augmentations.
Augmented Reality Device Operations
So how do augmented reality devices work? The objective of augmented reality is to bring computer-generated objects into the real world and allow real-time interaction. To show the relevant content to the user AR uses computer vision, simultaneous localization, mapping and depth tracking (calculating the distance to the objects).
First computer vision tries to understand what all objects are there in the real-world around the user from the content of the camera feed. The digital content relevant to what user is looking for is then displayed in a realistic way so that it looks like a part of the real world. This process is known as rendering. Consider an example, playing an augmented reality board game using a box as physical support. First, computer vision identifies and processes the raw image from the camera and recognizes the box and then the rendering module augments the original frame with the AR game making sure that it overlaps the box correctly.
What is the role of computer vision? The computer vision helps in analyzing the raw data captured from the camera of the device. It understands the objects in the real world in terms of semantics and 3D geometry. Semantics means understanding what object it is. For example, a table, a box, etc. 3D geometry explains where the objects are placed and in what way they are facing in the three-dimensional world. Without geometry, the augmented objects cannot be displayed at the right place and angle, which is necessary to make it feel like the part of the real world.
What all are the key components of augmented reality devices? The key components of augmented reality devices include camera and sensors, processors, projectors and reflectors. The camera captures pictures around the user, which in turn becomes the raw data for the processors. The camera on the device scans the surroundings and with this information physical objects are located, and 3D models are generated. Just like the usual computers the AR devices also require a CPU/GPU, RAM, flash memory etc. These processors calculate the angle, direction, orientation in space etc. of the raw data collected by the camera. Now, the processed data taken by the camera and sensors needs to be projected in front of the user. For this, we need a projector which can turn any surface into an interactive environment.
Mirrors are used in some AR devices to assist the human eye to view the virtual images. Some may have “an array of many small curved mirrors” while others may have a double-sided mirror to reflect light to the camera as well as the user’s eye. The goal of such reflection path is to form a proper image alignment.
Augmented Reality Applications
Augmented reality has a wide range of application in the current world. A large number of AR based games have emerged in the past few years with the rise of smartphones. AR has also been in the medical field since it can benefit students with live 3D models. It also projects information directly onto the patient’s skin. For instance, in the Veinviewer system the real-time images of infrared vein scans are directly projected onto the patient’s skin by creating an impression of transparent skin.
AR technology has turned out to be very useful in the military field as well. Soldiers wearing head-up displays can see information tagged onto real-world objects. Many smartphones, especially iPhone use AR apps that allows to observe the computer-generated images superimposed over real-world objects. In the arena of marketing and advertising, augmented reality enhances the product aspects to enrich a customer’s experience by creating a real-time manifestation of the product in use.
Types of Augmented Reality Technology
The Marker-based augmented reality uses a camera on the device to scan a marker such as QR/2D code from the real world and replaces it with a virtual object. The Location-based augmented reality makes use of the user’s location with GPS and adds information about the objects that can be seen from the camera of the user. GPS software recognizes the location of the device in the app and then the digital information captured through a smartphone camera is matched with the real scene.
The Superimposition based augmented reality involves the partial or complete replacement of an object with a newly augmented view of that same object. Here object recognition plays a crucial role because the application can replace the original view only if the object is perceptible. The Projection based augmented reality works by projecting artificial light onto real-world surfaces. This type of AR involves throwing light on a real-world surface and then sensing the human interaction of that projected light. It's by differentiating between an expected projection and the altered projection that the human interactions involved are detected and recorded.
In the future, we expect to see a lot of development in augmented reality technology. As computer vision gets better at understanding the world around us, AR experience becomes much better and exciting. With AR being widely used in smartphones, it is likely to be in our day to day lives soon in the future. As time passes, there may or may not be many changes in technology, but it is sure that AR would find its place in the everyday life of many people.
