October 13, 2023

Kathlyn Phan

11th Grade

Fountain Valley High School

Chances are that the majority of people have encountered, scanned, or generated a QR code at some point in their daily lives. We see them being used everywhere both in the digital and physical world around us. QR codes have been utilized to replace physical copies of menus in restaurants to prevent the spread of germs since COVID-19, to advertise by taking the user to a company’s web address, to share contact information conveniently, etc. According to Roselle from QR Tiger, QR codes have grown 443% year-on-year in usage in 2022 alone. Their rise in popularity stems from their vast capacity for storing URLs, text, photos, and videos. Barcodes can only contain 20-100 characters. Meanwhile, QR codes can contain up to 7,089 numeric and 2,953 alphanumeric characters. QR codes can contain multiple data types; such as numeric, alphanumeric, byte, and kanji. Additionally, whereas barcodes are limited by the amount of data they can store due to them only being able to be read horizontally, QR codes are two-dimensional and can be read both horizontally and vertically.

From the necessity for a technology that can quickly scan and contain a bulk of data, QR codes were created as a two-dimensional barcode. In 1994, Masahiro Hara, a Japanese engineer working for Denso Wave, developed the QR code when the manufacturing process in their company became very complicated. Denso Wave is an automobile company that is a branch of Toyota and specializes in the manufacturing of car parts. To transform the sorting and storing of car components, QR codes were designed to carry more information and be read faster than their predecessor, the traditional barcode. The QR code’s design was inspired by the Chinese board game, “Go”, for its simple yet distinct black and white design. The design was translated into black and white pixels, which were embedded with code. Although QR codes are much newer and require higher technology than barcodes, their capacity for large amounts of content, minimal design, multiple data types, and quick speed make them the future of digital scanning. 

At first, QR codes may seem like random configurations of black and white squares, but those squares are inscribed with code. To create a QR code, numeric, alphanumeric, bytes, and kanji are converted into binary code composed of 0’s and 1’s. This binary code is then turned into a configuration of two-dimensional squares that have their original content embedded inside. The 0’s are represented by the white squares while the 1’s are represented by the black squares. Similar to barcodes, the black and white color scheme is used to create a high amount of contrast between the black squares and the white background in a QR code. This makes it easier for software within the scanning device to recognize the code, thus contributing to QR codes’ high scanning speeds. Once they are read by a scanner or smartphone camera, the internal software takes the code as the input and translates it back into the content’s original form as the output.

The structure of a QR code has multiple moving parts that ultimately work together to deliver high scanning speeds. QR codes have built-in error correction that can be one of four levels. The different levels correspond to how much of the total code can be flawed without its functionality being impacted. This allows for the code to be deciphered efficiently with a forgiving margin for error. The finder pattern stands out with its unique configuration made of an inner and outer eye. This pattern can be located at the code's top left, top right, or bottom left corners. It is responsible for being used as a position marker and helping scanners locate the data modules and scanning direction with both accuracy and speed. Although it may appear to be a series of seemingly random black-and-white squares at first, this is called a “module”. The data modules are the pixels that make up the majority of the code because they contain the majority of the content data. Each module holds a piece of embedded code. When scanned, these modules can be put together and decoded to deliver the user to their desired destination. 

To start, our scanners or cameras first recognize the three finder patterns to determine their orientation and scanning direction. Once the software has this information, it starts scanning from the bottom right corner to read the “mode indicator”, which provides what data type of the embedded code. From there, it will read the “character count indicator” to establish how many characters are contained in the code. QR codes can range anywhere from 21 x 21 pixels up to 177 x 177 pixels, so it’s important to understand how much content is being given. Now that the scanner has the data type and character length, it will read along the data modules in a zig-zag pattern to collect all of the embedded content. Once the scanner or camera reaches the end of the data modules initialized by the end indicator, the scanner will proceed to the error correction data module. Finally, the software will output the content to the user in the form of a web address, an image, a video, etc.

Although QR codes seem like the clear path to virtualizing the physical world around us, there are some drawbacks to their simplistic design. Since they rely heavily on a smartphone with a stable internet connection, it may be inconvenient for those without access to them. Now that we’re entering the digital age, more and more businesses are replacing physical resources with QR codes. For example, someone whose phone does not have stable cellular data would be unable to access the menu at a restaurant that replaced all their menus with a QR code. It can also be difficult for users to trust such technology because of how unfamiliar it is. For instance, it’s easy for hackers to use and redirect people to dangerous sites because people can’t recognize the web address before they scan it. Just like all technological advances, there are always pros and cons.

As we progress into the future, technology will continue to become more and more involved in everyday life. QR codes can be found practically everywhere now; such as gym memberships, buses, advertisements, business cards, and even on currency in Russia and Ghana. Since 2020, there has been a 26% increase in QR code usage from roughly 90 million United States citizens. It has been predicted that their technology will only continue to grow upwards of 10% in the following years. Due to the rise of mobile phone usage and the subsequent need for touchless solutions, QR codes will continue their rampant growth in popularity far into the future.