Augmented reality

AUGMENTED REALITY
Narendra Kumar Jha
1602-13-725-313

Contents
Introduction
Augmented reality
o Augmented reality vs Virtual reality
o History
o Augmenting our world
Implementation
Components of AR system
o Display technology
o Tracking & orientation
o Software requirement
Applications
Recent development
Limitations
Looking into future..
Conclusion
References

Introduction
Augmented reality will truly change 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. In this article, we
will take a look at this future technology, its components and how it will
be used.

Augmented Reality
It is the process of superimposing digitally
rendered images onto our real world surroundings.
 Recent developments have made this technology
accessible using a Smartphone.
The world environment around us provides a
wealth of information that is difficult to duplicate in a
computer.
Also the computer cannot know on its own about
what we are looking for.
 With the help of advanced AR technology (e.g.
adding computer vision and object recognition) the
information about the surrounding real world of the
user becomes interactive and digitally manipulable.

Augmented reality vs Virtual reality

Augmented reality vs Virtual reality
Augmented reality is closer to the real
world. Augmented reality add graphics and
sounds to the natural world, as it exists.
Thus it augments the real world scene in
such a way that the user can maintain a
sense of presence in that world.
That is ,the user can interact with the real
world, and at the same time can see, both
the real and virtual world co-existing.
User is not cut off from the reality.
Virtual reality creates immersive,
computer generated environments which
replaces real world.
Here the head mounted displays block out
all the external world from the viewer and
they have no sense of presence.
Virtual reality serves for at totally
immersive environment . The senses are
under control of the system.
The user is completely immersed is an
artificial world and cut off from real
world.

History
The beginnings of AR, as we define it, date back to Sutherland’s work
in the 1960s, which used a see-through HMD to present 3D graphics.
However, only over the past decade has there been enough work to
refer to AR as a research field.
In 1997, Azuma published a survey that defined the field, described
many problems, and summarized the developments up to that point.
Since then, AR’s growth and progress have been remarkable.

Augmenting Our World
The basic idea of augmented reality is to
superimpose graphics, audio and other sense
enhancements over a real-world environment in
real-time.
Sounds pretty simple. Besides, haven't
television networks been doing that with
graphics for decades?
These systems display graphics for only one
point of view. Next-generation augmented-
reality systems will display graphics for each
viewer's perspective.

How Does It Work?
Camera scans the target image.
Various parameters like distance from the target, orientation of the
camera with respect to target, are calculated from camera using
sensors.
The software application takes all these values and after using
processing techniques it overlays digital information over the target in
the display.

Implementation
To implement there are
three things that we require
to do,
i) find user’s location and
orientation (view)
ii) generating information
iii) augmenting it to user’s
view
Find user’s
location and
orientation
Generate data
Augment
generated data to
user’s view

Components of AR system
Here are the four components needed to make an augmented-reality
system work:
Display
Tracking system
Input device
Software application

Display technologies
Monitor Based Display
Head Mounted Displays:
Video see-through
Optical see-through

Monitor based AR
Simplest available
Treat laptop/PDA/cell phone as a window through which you
can see AR world.
Real
world
Camera
position
Augmented view
Virtual
objects
Graphics
system
Video of
real scene
Video
merging Augmented
video

Head-mounted displays
Head-mounted displays (HMDs) will enable us to view graphics and
text created by augmented-reality systems through a wearable
device.
There are two basic types of HMDs:
1. video see-through
2. optical see-through

Video see through HMD
 They block out the user's surrounding environment, using small video
cameras attached to the outside of the goggles to capture images.
 On the inside of the display, the video image is played in real-time and
the graphics are superimposed on the video.
 One problem with the use of video cameras is that there is more lag,
meaning that there is a delay in image-adjustment when the viewer
moves his or her head.

Optical see through HMD
 Optical see through is not fully realized yet.
 It is supposed to consist of ordinary looking
pair of glasses that will have light source on
the side to project digital images onto the
glass.

Tracking and orientation
The biggest challenge facing developers of augmented reality
is the need to know where the user is located in reference to
his or her surroundings.
There's also the additional problem of tracking the movement
of users' eyes and heads.
AR system needs to know
1. Where is the user located (position)
2. Where is the user looking (orientation)

Tracking and orientation
Modern mobile augmented-reality systems use one or more of
the following tracking technologies: digital cameras and/or
optical sensors, accelerometers, GPS, gyroscopes, solid state
compass.
 These technologies offer varying levels of accuracy and
precision.
Tracking the user's hand(s) or a handheld input device can
provide a 6DOF (degrees of freedom) interaction technique.

Degree of freedom
 Degrees of freedom or DOF is the way an object can move within
a 3D space. There are a total of 6 degrees of freedom in a 3
dimensional space. The 6 DOF can be divided into 2 categories,
rotational movements and translational movements.
 The 3 translational movements are left/right, forward/backward
and up/down. These movements are usually tracked by an external
camera or other sensors.
 The ability to tracking translational movements are required
for positional tracking, the ability to determine the absolute
position of an object in a 3D environment.
 The 3 rotational movements are pitch, yaw, and roll. These
movements are tracked by most HMD’s on-board sensors. As you
tilt and turn your head, the HMD senses the movements and alters
its display accordingly.
 Rotational Movements are tracked by IMUs or inertial measurement
units consist of accelerometer, gyroscope and magnetometer.
x
y
z

Input devices
Techniques include speech recognition systems that translate a user's spoken words into
computer instructions and gesture recognition systems that can interpret a user's body
movements by visual detection or from sensors embedded in a peripheral device such as
a wand, stylus, pointer, glove or other body wear.
Wearable computer analyzes the sensed visual and other data to synthesize and position
augmentations.
A wearable computer is a battery powered computer system worn on the user’s
body(belt, backpack etc).
It is designed for mobile & predominantly hand free operations often incorporating
head mounted display & speech input.

Software requirement
A key measure of AR systems is how realistically they integrate augmentations with the
real world. The software must derive real world coordinates, independent from the
camera, from camera images. That process is called image registration which uses
different methods of computer vision, mostly related to video tracking.
Usually those methods consist of two parts.
The first stage is to detect interest points, fiducial markers or optical flow in the
camera images. This step can use feature detection methods like corner detection, blob
detection, edge detection or thresholding and/or other image processing methods.
 The second stage restores a real world coordinate system from the data obtained in the
first stage.

Applications
AR in education:
In educational field, AR has been used to complement a standard
curriculum. Text, graphics, video and audio were superimposed
into a student’s real time environment. Textbooks, flashcards and
other educational reading material contained embedded “markers”
or triggers that, when scanned by an AR device, produced
supplementary information to the student rendered in a
multimedia format.
Anatomy students could visualize different systems of the human
body in three dimensions.
AR in industrial design:
AR allowed industrial designers to experience a product's design
and operation before completion. Volkswagen used AR for
comparing calculated and actual crash test imagery.

Applications
AR in architecture:
AR can aid in visualizing building projects. This was
demonstrated publicly by Trimble Navigation in 2004.
 AR can also be employed within an architect's work space,
rendering into their view animated 3D visualizations of
their 2D drawings.
Augmented reality is applied to present new projects, to
solve on-site construction challenges, and to enhance
promotional materials. Examples include the Daqri Smart
Helmet, an Android-powered hard hat.

Applications
AR in defence:
The military has been devising uses for augmented
reality for decades. The idea here is that an
augmented-reality system could provide troops with
vital information about their surroundings, such as
showing where entrances are on the opposite end of a
building, somewhat like X-ray vision.
Augmented reality displays could also highlight troop
movements, and give soldiers the ability to move to
where the enemy can't see them.
In combat, AR can serve as a networked
communication system that renders useful battlefield
data onto a soldier's goggles in real time. From the
soldier's viewpoint, people and various objects can be
marked with special indicators to warn of potential
danger.

Applications
AR in commerce:
AR is used to integrate print and video marketing.
Printed marketing material can be designed with
certain "trigger" images that, when scanned by an AR
enabled device using image recognition, activate a
video version of the promotional material.
AR can enhance product previews such as allowing a
customer to view what's inside a product's packaging
without opening it.
AR can also be used as an aid in selecting products
from a catalog or through a kiosk. Scanned images of
products can activate views of additional content
such as customization options and additional images
of the product in its use.

Applications
AR applied in the visual arts allows objects or places
to trigger artistic multidimensional experiences and
interpretations of reality.
AR has become common in sports telecasting. Sports
and entertainment venues are provided with see-
through and overlay augmentation through tracked
camera feeds for enhanced viewing by the audience.
AR can also be used to depict historic events
occurred at the historic places for the viewing of the
users.
AR is also used for navigation purposes and to locate
different places.

Recent development
HOLOLENS:
The Microsoft Hololens demos showed that
AR can be social, collaborative, and in the
real world. More importantly, you forget
that you’re even wearing it.
It is more about solving problems, creating
new products, and editing models in a 3D
environment to better visualize the final
product.

Limitations
Accurate tracking and orientation.
Update rate for generating the augmented image also limits the performance of AR.
The concept of modern augmented reality depends on the ability of the device to
record and analyze the environment in real time. Because of this, there are potential
legal concerns over privacy.
Failure in image registration may arise due to noise, time delays or distorted images.
People working in an augmented reality are more sensitive to alignment errors. Proper
calibration and alignment with the reference frame of the world is crucial.

Looking into future
Expanding a PC screen to real environment like program windows & icons appear as
virtual display in real space & are eye or gesture operated, by gazing or pointing.
Replacement of cell phones: eye dialing, insertion of information directly into
environment.
It may allow computer-generated imagery to interact with live entertainers and
audience.
By 2020, AR will find its way in many more fields and it will come within the reach of
common man.

Conclusion
Augmented reality is another step further into the digital age as we
will soon see our environments change dynamically either through a
Smartphone, glasses, car windshields and even windows in the near
future to display enhanced content and media right in front of us.
This has amazing applications that can very well allow us to live our
lives more productively, more safely, and more informatively.

References
 https://www.youtube.com/watch?v=H9ZOpQzjukY
 https://en.wikipedia.org/wiki/Augmented_reality
 https://en.wikipedia.org/wiki/Six_degrees_of_freedom
 https://www.youtube.com/watch?v=D-A1l4Jn6EY&t=3s
 https://www.youtube.com/watch?v=09vxKN1zLNI
 http://computer.howstuffworks.com/augmented-reality.htm

Augmented reality

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