
AR is a direct or indirect live view of a physical world environment. An enhanced version of reality where live direct or indirect views of physical real-world environments are augmented with superimposed computer-generated images over a user’s view of the real-world, thus enhancing one’s current perception of reality.
Adding graphics into your TV screen or computer and integrating them into our real/physical-world environments. This new technology, called Augmented Reality, hides the border between what’s real and what’s computer-generated by enhancing what we see, hear, feel and smell.
Augmented reality adds graphics, sounds and smell to the natural world as it exists.
Augmented reality is changing the way we view the world. Picture yourself walking or driving down the street. With augmented-reality displays, which will eventually look much like a normal pair of glasses, informative graphics will appear in your field of view, and audio will coincide with whatever you see. These enhancements will be refreshed continually to reflect the movements of your head. Devices and applications already exist, particularly on smartphones like iPhone.
Types of Augmented Reality :-
Marker Based Augmented Reality

Marker-based augmented reality (or Image Recognition). It uses a camera and some type of visual marker like QR code etc, to give a result only when the marker is sensed by a reader.
Marker based technology use a camera on the device to recognize a marker from any other real world object. Simple distinct patterns (like QR code) are used as the markers, because they can be easily identified and do not require a lot of time to read and processing.
Markerless Augmented Reality
One of the most widely implemented applications of augmented reality is markerless (location-based / position-based / GPS) augmented reality. It using a GPS, digital compass, velocity meter/ accelerometer which is embedded in the device to provide data based on your location. Plus point of markerless augmented reality technology is, smartphones and its location features which we are using. This technology mainly using for direction mapping, finding nearby friends/businesses etc, and other location based mobile applications.
Projection Based Augmented Reality

Projection based augmented reality works by projecting artificial light onto real world surfaces. It can be interactive and project a digital keyboard on your desk, or a dialer on your hand. It allow for human interaction by sending light onto a real world surface and then sensing the human interaction (i.e. touch) of that projected light.
For example, it may be show you if your any furniture or any other objects will fit into any of your space which you imagined.
Another interesting application of projection based augmented reality utilizes laser plasma technology to project a three-dimensional (3D) interactive hologram into mid-air.
Superimposition Based Augmented Reality

Superimposition based augmented reality – It will show partially or fully newly augmented objects, instead of its original objects. Which means it replaces the original view with newly augmented view of that same object.
For example :- in medicine, a doctor can use this technology to superimpose an X-ray view of a patient’s broken arm bone on a real image to provide a clear understanding of what the bone damage actually is.