Despite the growing trend of augmented reality, many people still wonder what superimposition means and how this technology actually augments our reality.

Probably you have tried some mobile apps based on augmented reality (AR) like IKEA Place, but not sure how all the magic happens on a screen of your smartphone? What are the other technologies AR relies on?

Keep reading to sort things out.

Vocabulary

• Computer-generated content – any content in the form of graphics, image, video, animation, or three-dimensional objects generated by software.
• Virtual reality – an immersive technology, which replaces real-world environment with the virtual one using special hardware like VR glasses.
• ARCore – an augmented reality API tool for developers created by Google.
• ARKit – another augmented reality API tool for developers built by Apple.
• GPS – The Global Positioning System, which can track the location of any device enabled with this technology.
• Gyroscope – a device aimed at determining the orientation and angular velocity.
• Accelerometer – a device that measures changes in the gravitational acceleration.
• QR-code – a machine-readable label that contains some data like a link or digital trigger.

What is Augmented Reality?

AR is a technology that augments physical environments on a mobile device screen by overlaying them with digital content.

When it comes to the difference between virtual and augmented reality, these are completely different technologies. Unlike VR, AR is based on a footprint of a real surrounding and it only adds additional computer-generated data like animation or three-dimensional objects to it instead of replacing the virtual one.

With the growth in the number of smart mobile devices and the continuous improvement of their capabilities, augmented reality has penetrated a number of aspects of human life. This has become an interactive concept that affects how we buy or study.

To superimpose digital information, AR applications can use different methods like connecting computer-generated content to ‘markers’ or determining the point where to add data with GPS.

Furthermore, the immersive technology implies overlaying additional content in real-time and within the context of the surrounding, for example, superimposing a copper cask with explanations of how coffee beans are roasted as it happens in the Starbucks’ Roastery AR app.

See also: What Is the Difference between Augmented and Virtual Reality?

How does augmented reality work?

Augmented reality can be divided into four main phases, which make additional content superimposition possible:

1. An AR solution captures a part of the environment using a camera on a smartphone, tablet, or head-mounted display (HMD).
2. Then it scans the captured piece of the environment to identify a point where to overlay additional information using markers or trackers like infrared, laser, GPS, or sensors.
3. As soon as this point is determined, an augmented reality solution requests predefined content to overlay further an environmental footprint with additional information.
4. Once the necessary content is requested, the solution forms a complete image consisting of the real-world background and overlaid AR data.

Regardless of the fact that the augmented reality relates to the expansion of the physical environments with overlaid information, there is a number of ways to implement this concept.

When it comes to the approaches behind AR, the immersive technology can be based on the following:

• SLAM
• Markers
• Position

When choosing between approaches, augmented reality developers take into account the pros and cons of each of them, as well as requirements of the final project.

Let’s look closer at each approach.

SLAM

SLAM stands for simultaneous localization and mapping technology. It is based on a set of complex algorithms and data received from sensors. So, SLAM maps unknown environments and determines its localization simultaneously.

However, SLAM has some of the drawbacks for augmented reality companies. As it’s one of the most advanced technologies to enable augmented reality, it has high requirements for hardware components. In addition, SLAM-based apps require a predefined map in order to properly place virtual 3D objects.

SLAM allows computers to understand what is around them using point-based detection of surrounding objects.

This approach is a key driver of such innovations as autonomous vehicles, robots, and drones.

Marker-based

Augmented reality that relies on markers is the most widespread approach to the immersive technology implementation. Marker-based AR or image recognition uses a mobile device camera to detect a predefined marker that then triggers a certain computer-generated content.

Markers can be AR-codes, physical objects, or printed images as it appears in the Absolut Vodka Augmented Reality app. To enable the AR app to recognize a real-world object as a trigger, a certain marker should be embedded into this object.

Since AR-codes are much easier to recognize for both cameras and users, this type of marker is greatly used by augmented reality programmers.

As soon as a marker appears within a camera scene, the software calculates the position of both a marker and displayed content. Therefore, a change of the real-world object position will influence the position of the computer-generated content.

The better an app can determine certain physical objects, the more accurate the disposition of the overlaid digital information will be.

Location-based

To determine where to place additional digital information, position-based AR apps rely on GPS data, mobile device built-in compass, accelerometer, and gyroscope. It is also known as location/position-based augmented reality.

To enable an app to display properly computer-generated information, the latter has to contain a data-based trigger, for instance, geolocation. Thus, location-based AR applications link their content to real-world, which falls within the field of view of the camera.

For instance, such AR apps can tell users more about a restaurant situated on a certain street. When pointing a camera at the restaurant signboard, users can, for example, briefly check their menu or learn working hours.

Hardware requirements

Depending on a used approach behind a certain augmented reality experience, there’s a list of requirements for hardware each augmented reality app development company and their customers should keep in mind.

Sensors

Sensors collect data from the physical environment and then transmit them to an AR app. For instance, a mobile device built-in camera collects data about a user’s surroundings. Software processes received data and then displays predefined content to a user.

Processing

Smartphones, tablets, or AR smart glasses should be able to access data collected from gyroscope, accelerometer, compass, or GPS.

Moreover, to deal with the flow of data from various sensors, a specific device must have a  powerful enough central processing unit (CPU), graphics processing unit (GPU), flash memory, and random-access memory (RAM).

Displaying

To provide users with the augmented reality experience, hardware should have enough capability to display additional content. Therefore, a device obviously has to have a high-resolution display.

When it comes to projection-based AR solutions, hardware must have a specific projector, instead of a display, to transmit light.

AR hardware

After considering hardware requirements, let’s cover existing types of devices that support augmented reality.

Head-up displays

Head-up display, also known as HUD, is a transparent display that shows visual content within the scene of a user viewpoint. These solutions were originally developed for pilot training to help them learn how to fight in the air.

Over the time, HUDs found their application in civil aviation, automotive, and other industries. Their technology stack includes a projector, which transmits an image onto a display, combiner for capturing projected light, and video processor to generate visual data.

AR smart glasses

AR smart glasses are a wearable transparent device that generates AR content within the scene of the user’s viewpoint.

When wearing such glasses, users can see their physical surrounding in the same way as in the case of traditional glasses. However, AR smart glasses like Google Glass superimpose additional content to whatever users see.

AR smart lenses

AR smart lenses are a relatively new concept. In fact, this is an advanced version of smart glasses. Unlike smart glasses, users wear AR lenses the same way they wear dioptric contact lenses.

For instance, Samsung has a patent of smart lenses with a built-in camera and sensors controlled by blinking. This technology stack superimposes additional content to whatever a wearer sees.

Virtual retinal displays