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What Is Augmented Reality?
Augmented reality is…
● a technology
● a field of research
● a vision of future computing
● an emerging commercial industry
● a new medium for creative expression
Augmented reality is the display of computer graphics and media, overlaid and registered on real-world environments, interactively in real time.
Real vs. Virtual
Virtual Reality
● VR was first introduced by Jaron Lanier
● The term is defined as a computer generated , interactive , three dimensional environment in which a person is immersed.
● Eg: Virtual Keyboard
● Augmented reality will further blur the line between what's real and what's computer-generated.
● Real scene viewed by the user & virtual scene by computer augments
● Virtual reality + Reality =AR
● The idea of mixture of virtual with real objects is not new. Hollywood and photography people have used it since very long before…
Let’s Give a More Strict Definition
● Augmented Reality (AR) -supplements the real world with virtual (computer-generated) objects that appear to coexist in the same space as the real world.
● AR systems have the following three characteristics:
−Combines real and virtual objects in a real environment
−Runs interactively, and in real time
−Registers real and virtual objects with each other ( Registered in 3-D )
● AR platforms exist at the intersection of several technical disciplines, including computer graphics, machine vision, sensing and sensor fusion, geographic information systems, mobile systems, ubiquitous computing and the web.
Motivation
● The goal of AR is to create the sensation that virtual objects are present in the real world.
● Ivan Sutherland’s vision of AR -User is “inside” the computer
● AR enhances a user’s perception of interaction with the real world.
● The virtual objects display information that the user cannot directly detect with his own senses. The information conveyed by the virtual objects helps a user perform real-world tasks.
● AR is a specific example of what is known as Intelligence Amplification (IA): using the computer as a tool to make a task easier for a human to perform.
AR System Components
The three basic components of an augmented reality system are:
● The Head-Mounted Display
The head-mounted display used in augmented reality systems will enable the user to view superimposed graphics and text created by the system. −Optical see-through based
− Video see-through based
● Tracking and Orientation
This system pinpoints the user's location in reference to his surroundings
and additionally tracks the user's eye and head movements.
−Indoor tracking
−Outdoor tracking
● Portable Computer
Augmented reality systems will need highly mobile computers.
Optical See-through Based AR
Optical see-through systems make use of technology that "paints" the images directly onto the user's retina through rapid movement of the light source.
Video See-through Based AR
The video see-through systems block out the user's view of the outside environment and play the image real time through a camera mounted on the head gear.
Characteristics
1. Augmentation
Discussion on the characteristics of AR systems and design issues encountered when building an AR system.
● Besides adding objects to a real environment, AR also has the potential to remove them.
● AR might apply to all senses, not just sight.
● AR could be extended to include sound.
Another example is haptics
2. Optical vs. Video
● When virtual objects are added to a scene , it is known as visual AR.Visual AR relies up on some sort of display.
● Head Mounted Displays(HMD) will enable us to view graphics and text created by AR system.
● A basic design decision in building an AR system is how to accomplish the combining of real and virtual. Two basic choices are available:
-Optical see through based
-video see through based
3. Focus & Contrast
● Focus can be a problem for both optical and video components. Ideally the virtual should match the real.
-Depending on video camera’s depth-of-field (DOF) and focus settings, parts of the real world may not be in focus.
-In computer graphics, everything is rendered with a pinhole model, so regardless of distance, everything is in focus.
-To overcome this, graphics can be rendered to simulate a limited DOF, and the video camera can have auto focus lens
● Contrast is a big issue owing to its large dynamic range in real environments.
-If the real environment is too dark, the virtual image will wash out the real world. If the real world is too bright it will wash out the virtual image.
-Human eye can detect a wide range of dynamic environment. Optical devices are usually made dark-tinted to reduce this range. For video, everything must be clipped or compressed into the monitor’s dynamic range.
4. Portability
● In most VR systems, the user is not encouraged to walk around much.
-Instead, the user navigates by "flying" through the environment, walking on a treadmill, or driving some mock-up of a vehicle, etc.
-Whatever the technology, the result is that the user stays in one place in the real world.
● Some AR applications, however, need support for a user who will walk around a large environment (usually move to the place where the task is to take place).