Chapter Five
Augmented Reality (AR)
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Overview of augmented reality
The fundamental idea of AR is to combine, or mix, the view of
the real environment with additional, virtual content that is
presented through computer graphics.
Its convincing effect is achieved by ensuring that the virtual content
is aligned and registered with the real objects.
Augmented reality (AR) is a form of emerging technology that
allows users to overlay computer- generated content in the real world.
It refers to a live view of a physical real-world environment
whose elements are merged with augmented computer-generated
images creating a mixed reality.
28/05/2025 Prepared by: Abinet A. (MSc) 2
Overview of augmented reality…
The augmentation is typically done in real-time and in
semantic context with environmental elements.
So, it makes the information about the surrounding real
world becomes interactive and digitally usable.
Through this augmented vision, a user can digitally interact with
and adjust information about their surrounding environment.
Unlike virtual reality, which creates a totally artificial
environment, augmented reality uses the existing environment and
overlays new information on top of it.
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Virtual reality (VR), AR vs Mixed reality (MR)
Virtual reality (VR)
VR is fully immersive, which tricks your senses into thinking
you’re in a different environment or world apart from the real world.
Using a head-mounted display (HMD) or headset, you’ll experience
a computer-generated world of imagery and sounds in which you can
manipulate objects and move around using haptic controllers while
tethered to a console or PC
It refers to computer technologies using reality headsets to
generate realistic sounds, images and other sensations that replicate
a real environment or create an imaginary world.
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Virtual reality (VR), AR vs Mixed reality (MR)…
Figure 5.2 Example of Immersive Technology
Using VR devices such as HTC Vive, Oculus Rift or Google Cardboard, users can be transported into a
number of real-world and imagined environments.
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Virtual reality (VR), AR vs Mixed reality (MR)…
Most VR headsets are connected to a computer (Oculus Rift) or a
gaming console (PlayStation VR) but there are standalone devices
(Google Cardboard is among the most popular) as well.
Most standalone VR headsets work in combination with
smartphones – you insert a smartphone, wear a headset, and immerse
in the virtual reality
Figure 5.3 VR Case that Inserts a Smartphone
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Virtual reality (VR), AR vs Mixed reality (MR)…
Augmented Reality (AR)
In augmented reality, users see and interact with the real world while
digital content is added to it.
There’s a different way to experience augmented reality, though –
with special AR headsets, such as Google Glass, where digital content
is displayed on a tiny screen in front of a user’s eye.
AR adds digital elements to a live view often by using the camera on a
smartphone. Examples of augmented reality experiences include Snapchat
lenses and the game Pokemon Go.
AR is a live, direct or indirect view of a physical, real-world environment
whose elements are augmented (or supplemented) by computer-generated
sensory input such as sound, video, graphics or GPS data
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Virtual reality (VR), AR vs Mixed reality (MR)…
Figure 5.4 Direct and Indirect Augmentation of Objects
Mixed Reality (MR) is referred to as hybrid reality, is the merging of real and
virtual worlds to produce new environments and visualizations where physical
and digital objects co-existand interact in real-time.
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Virtual reality (VR), AR vs Mixed reality (MR)…
It means placing new imagery within a real space in such a way
that the new imagery is able to interact, to an extent, with what is
real in the physical world we know
For example, with MR, you can play a virtual video game, grab
your real-world water bottle, and smack an imaginary character from
the game with the bottle. Imagination and reality have never been so
intermingled.
The key characteristic of MR is that the synthetic content and the
real- world content are able to react to each other in real-time.
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Virtual reality (VR), AR vs Mixed reality (MR)…
Figure 5.5 Mixed Reality in Engineering and Medicine
MR allows you to see and immerse yourself in the world around you even as you interact with a virtual
environment using your own hands—all without ever removing your headset.
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Virtual reality (VR), AR vs Mixed reality (MR)…
It provides the ability to have one foot (or hand) in the real world,
and the other in an imaginary place, breaking down basic concepts
between real and imaginary
One of the most obvious differences among augmented reality,
virtual reality, and mixed reality is the hardware requirements and
also VR is content which is 100% digital and can be enjoyed in a fully
immersive environment, AR overlays digital content on top of the
real-world
And MR is a digital overlay that allows interactive virtual elements
to integrate and interact with the real-world environment.
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Virtual reality (VR), AR vs Mixed reality (MR)…
• Numerous augmented reality apps and games can run on almost every
smartphone on the market.
• On the other hand, virtual reality programs require specialized VR
headsets, noise-canceling headphones, cameras to track room space
and boundaries, and sometimes even motion capture technology.
• Some of the biggest names in VR tech today are the Oculus Rift, HTC
Vive, and PlayStation VR.
• Mixed reality hardware is still emerging and hasn’t quite broken into
the mainstream consumer market, most likely due to the price.
• The consumer releases of the Microsoft HoloLens and Magic Leap
One retail for over $2000 USD, which is 3 to 4 times the cost of the
PlayStation VR and HTC Vive VR headsets.
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Virtual reality (VR), AR vs Mixed reality (MR)…
• However, mixed reality applications sometimes require exponentially
more processing power and thus require more powerful hardware.
• For example, the Microsoft HoloLens includes a built-in microphone
array, binaural sound capabilities, a built-in camera for recording, a
depth sensor, head-tracking cameras, and an inertial measurement unit
which helps track your head movement.
• On top of the traditional CPU and GPU, Microsoft also created a
Holographic Processing Unit to help track where the user is looking
and understand command gestures.
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The architecture of AR Systems
• The first Augmented Reality Systems (ARS) were designed with three
main blocks:
1) Infrastructure Tracker Unit
2) Processing Unit, and
3) Visual Unit.
The Infrastructure Tracker Unit was responsible for collecting data
from the real world, sending them to the Processing Unit, which mixed
the virtual content with the real content and sent the result to the Video
Out module of the Visual Unit.
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The architecture of AR Systems…
Figure 5.7 Augmented Reality Systems (ARS) standard architecture
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The architecture of AR Systems…
Visual Unit can be classified into two:
• Video see-through: It uses a Head-Mounted Display (HMD) that
employs a video-mixing and displays the merged images on a closed-
view HMD.
• Optical see-through: It uses an HMD that employs optical combiners
to merge the images within an open-view HMD.
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Applications of AR Systems
• The newest developing technologies, augmented reality (AR) can be
applied to many different disciplines such as education, medicine,
entertainment, military, etc.
AR In education:
Augmented reality allows flexibility in use that is attractive to
education.
AR can be used to enhance content and instruction within the
traditional classroom, supplement instruction in the special education
classroom.
More importantly, the following reasons for using augmented reality in
education:
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Applications of AR Systems…
• Affordable learning materials - posters, digital illustrations, physical
models, prototypes are very expensive and it’s impossible for schools
to find enough money to purchase all the supplementary materials they
would like to. Using AR technology allows for avoiding investments
in physical materials.
• Interactive lessons - when AR technology is used in classrooms,
students can view models on their own smartphones and get a better
idea of the concepts they are studying.
• Higher engagement - when teachers integrate augmented reality into
their lectures, they attract the attention of their students and make
lessons more effective.
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Applications of AR Systems…
AR In Medicine
augmented reality has already made significant changes in
the following medical areas:
surgery (minimally invasive surgery);
education of future doctors;
diagnostics;
AR tools may also aid to detect the signs of depression and other
mental illnesses by reading from facial expressions, voice tones, and
physical gestures.
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Applications of AR Systems…
Generally, AR provides the following benefits to patients
and healthcare workers:
Reduce the risks associated with minimally invasive surgery.
Better informed decisions about the right treatment and illness
prevention.
Make procedures more tolerable.
Better aftercare
Medical training and education.
Assistance in medical procedures and routine tasks.
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Applications of AR Systems…
AR In Entertainment
Augmented reality can be used in various ―entertainment‖ industries
such as: music, movies, live shows, games.
AR in games - the AR games were praised for increasing physical activity
in people – you actually have to move around to find your target, for
example, Pokémon.
AR in music – AR uses to find out more about music background: the
performers’ bios, the lyrics of the song, the making of the recording or the
music video.
Provides complete information on the track or its performer
It can enhance live performances by illustrating the story told by a track or
displaying the way it was created by the band.
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Applications of AR Systems…
AR in eSports - Augmented reality turns eSports shows into
interactive experiences allowing the watchers to become participants.
AR in the theater -The possibility to overlay virtual objects over the
real environment can be used, for example, for subtitling in various
theater shows.
Now, many theaters use LED displays either to provide subtitles for
translation or to assist hearing-impaired visitors.
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