Communication Entertainment Issue IV Lifestyle Volume XIX

EE-101: Intro to Emoji Engineering

Written by: Rajan Paul

About the Author: Rajan is a junior studying Electrical Engineering at the University of Southern California. His interests include beekeeping, ethnic cuisine, and travel. Rajan hopes to combine his hobbies and education into developing a smart beehive that will help save the bees.


Emojis have officially entered into the realm of popular culture, and while they may seem like a trivial part of our lives (thanks to an animated feature film that gives a 3.2 out of 10 stars), there is a lot of engineering involved with developing emojis. As with any technology, emojis are not perfect, and there is room for improvement. Thanks to the hard work of the developers that maintain this protocol, our beloved little faces and icons are able to convey what our words cannot.



Figure 1. An emoticon of a happy face

Before babies are able to understand their parents’ words, they learn how to read facial expressions. We retain this ability even after learning to understand language because much of our interaction is nonverbal. Our ability to nonverbally communicate is an example from our evolutionary history as a trait that helped us to survive as a species. Humans are social creatures, and we are raised to share our feelings and emotions within tight-knit communities [3]. However, in modern society, we utilize text-based wireless communication that sometimes lacks the ability to properly convey human emotion.


The initial solution to portraying emotion through text was the use of emoticons, a portmanteau of emotion and icon. This meant using the existing characters within the American Standard Code for Information Interchange (ASCII) to form faces, like the one seen in Figure 1. However, in the 1990s, a new standard called the Universal Coded Character Set (Unicode) was implemented in order to include non-Latin characters such as the Chinese script [4]. With the adoption of this new protocol, there was much more room for new characters and symbols. In 1999, a group of researchers from Japan developed emojis for use on Japanese mobile phones. The name emoji comes from the Japanese words for picture and character. By 2010, most phone manufacturers had implemented emojis into their mobile operating systems, and they became internationally popular.

What is an Emoji?

Before we can understand what an emoji is, we have to understand what a character is. A character is any printed letter or symbol. However, a computer does not store a character as its letter or symbol. Instead, each character is assigned a unique value which a computer can send to another computer [5]. You can see the values assigned to different characters for ASCII in Figure 2. When you are writing a message, your phone records the value for each character you type. It then sends this array of values to the intended recipient. When a phone tries to display a message, the received character values are converted into images of the actual letters or symbols [7]. ASCII is only able to represent 256 unique characters. The most common 128 characters and their values are shown in the ASCII table, but there exist 128 additional characters known as Extended ASCII Codes. These characters were allocated to ASCII because they are the most widely used characters in the English language.

Figure 2. ASCII Table

On the other hand, Unicode is able to store up to 1,114,112 unique characters. Only about 10% of these have been allocated, leaving room for new characters to be added in the future. In order to maintain backwards compatibility between Unicode and ASCII, the first 256 characters of each standard is the same. The first 256 characters are given the same numerical value, so that character number 10 is both “A” in ASCII and Unicode. This helps Unicode support legacy systems, which may have been written many years ago. Although these older systems may support the ASCII protocol and therefore the first 256 characters of Unicode, they will not support any of Unicode’s new and additional characters.

Following this understanding of characters, an emoji is essentially just a special character that has been assigned a value within Unicode. For example, the “grinning face” emoji is assigned a value of 128,512 within Unicode. Mobile phone manufacturers take this value and assign their own custom designs to it, which is why emojis look different on separate platforms, as seen in Figure 3. Companies spend a lot of time and effort into designing their emojis, because of how popular and widely-used they have become in our society.

Figure 3: Different Emoji Designs

How is an Emoji Made?

Creating new emojis is not a simple task. Every year, a committee called the Unicode Consortium meets to review proposals for the addition of new emojis into Unicode [8]. The specific requirements for proposals can be found online at, but the committee is essentially looking for an emoji that is not already represented by existing characters and that fulfills a necessity for internet communication. This means they are looking for an emoji that people will actually use and one that is not too similar to already existing emojis. In addition to a need for a certain type of emoji, the council looks for emojis that will be used by many people throughout the world. For them, choosing an emoji is like selecting a new character in the internet language, so it is important that each selection be utilized efficiently.

Figure 4: Broccoli Emoji Interest

Although these proposal requirements may seem easy and straightforward, they are longer and require more work than you may think. The committee looks to accept proposals which go into great detail justifying the need for that specific emoji. For example, the emoji proposal for a broccoli emoji, which was added to Unicode in 2016, was 8 pages long [2]. These 8 pages included statistical graphs showing broccoli’s greater average popularity compared to other fruits and vegetables, one of which can be seen in Figure 4. The proposal also includes tweets as evidence, showing that internet users wanted a broccoli emoji to be added. Upon successful admittance of a proposal, the Unicode standard is updated and sent to phone manufacturers to be implemented into their mobile operating system updates.

Problems with Emojis

A common challenge facing the use of emojis is due to translation error. Although emojis are given a universal value within the Unicode standard, it is up to mobile phone manufacturers to design and implement the actual pictures for the emojis. This leads to problems when a user of a certain manufacturer’s phone tries to send an emoji to his friend with a different type of phone. The emoji can look a bit different on each platform, as can be seen in Figure 3 [1]. This can create misinterpretations between what the sender meant and what the receiver understood.

Figure 5: Missing Emoji Box

In addition, some phone manufacturers will sell custom emoji packs to their users. These custom emojis are implemented solely by the phone manufacturer and were not allocated space in the Unicode standard. This means that the emojis only work on that specific manufacturer’s platform, and any other phones will receive an empty box as seen in Figure 5 [1]. This can lead to confusion and difficulties between mobile users, especially those who do not have the same types of phones. This can lead to other issues, like users with certain types of phone owners feeling excluded or left out. Some phone manufacturers have been criticized for maintaining closed ecosystems that discourage the use of other brands of phones. Considering how Unicode and much of the internet was built to be an open and inclusive platform, these phone manufacturers should reevaluate their policies.

In addition, emojis have long been criticized for not including enough diversity, especially in regards to people with darker skin not being accurately represented. Many mobile phone users felt that the emojis they were using portrayed only a certain portion of the population, and as such were not inclusive of all users [6].  Companies have tried addressing this problem, which they have admitted was created in the first place due to a lack of diversity amongst their own workforce. Thanks to this, many phones now allow the user to set the skin tone of their emojis, making the platform open and accepting to users from all racial and ethnic backgrounds.

Future of Emojis

There continues to be room for improvement and innovation when it comes to emojis. Following their most recent updates, some phone manufacturers now allow users to send animated emojis that display their real facial expression. Using facial tracking from the phone’s camera and 3D-rendering technology, the emoji now smiles when you smile or frowns when you frown. In addition, there are new companies trying to make emojis look more like the user. All these technologies have the same goal, which is to better communicate human expressions through a digital medium.

Emojis have become part of our daily lives. We all have our favorite emoji, because it is accurately able to convey what we are feeling. However, it is possible that your favorite emoji does not yet exist. Only a small amount of the values in Unicode have been allocated, and there is so much room for new and interesting emojis to be added into the lexicon. If you feel like you have a good idea for an emoji, you should write and submit a proposal to the Unicode Consortium. Your ideas may just be implemented for everyone around the world to use.


[1] “Android’s Emoji Problem,” Emojipedia, 2017. [Online]. Available:

[2] “Broccoli Emoji Submission,” Unicode Consortium, 2016. [Online]. Available:

[3] Fridlund, A. (1996). Human Facial Expression. San Diego: Academic Press.

[4] Kelly, Ryan, and Leon Watts. “Characterising the Inventive Appropriation of Emoji as Relationally Meaningful in Mediated Close Personal Relationships.” Experiences of Technology Appropriation: Unanticipated Users, Usage, Circumstances, and Design (2015).

[5] Haralambous, Y. and Horne, P. (2007). Fonts & Encodings. Sebastopol, Calif.: O’Reilly Media.

[6] Miller, Hannah, et al. “Blissfully Happy or Ready to Fight: Varying Interpretations of Emoji.” Proceedings of ICWSM 2016 (2016).

[7] Moore, Bradford Allen, et al. “Portable Touch Screen Device, Method, and Graphical User Interface for Entering and Using Emoji Characters.” U.S. Patent Application No. 12/365,888.

[8] “Submitting Emoji Proposals,” Unicode Consortium, 2018. [Online]. Available:


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