Qr Code

I always wandered how qr codes work, you go anywhere, find an image that is incredibly similar to all other images, and yet each code have different link. So what is it, how is it done and will it ever end, and in the first place who done it.

Mainly its a barcode made of a grid that have black and white squares. And data is stored in this grid horizontally and vertically. And when a camera scans it, the gird is translated into binary code (0,1) then converted to human readable information.

1. Finder patternes, which are the 3 corners, )2 top 1 bottom( that have large either squares and now more modernly circles, these acts as borders that tell the scanner where the code is located and which way it is allowing for 360 degree scan. While the official standard dictates square shapes, modern scanners are now smart enough to read stylized circle designs.


2. Beside each finder pattern, there are two lines called formate information (15-bit string of information), they serve the scanner by telling the error correction level (Low, Medium, Quartile, High) and the masking pattern that is applied to scramble the data. It is used because if the data is scrambled or masked or not clearly visible, the scanner would need formate information to know how to un-scambe the data. And because it is important for readability it is printed twice on the QR code in different locations so that if one corner is not clear, the scanner would take the decoding key from other corner.


3. There are timing lines (The Grid's Measuring Tape), one horizontal and one vertical, located at the innermost edge of top and bottom squares where it has one black one white dots and so on. Mainly the horizontal timing line runs along Row 6, connecting the top-left and top-right corners. The vertical timing line runs along Column 6, connecting the top-left and bottom-left corners. It does not touch the bottom-right area.


4. There is alignment patterns, located near the bottom right, they are used to correct misalignment of scanner cameras. So many times the qR code isn’t perfectly flat and it might be skewed so this placement allows the software to stretch and flatten the image back to perfect square so it could read the data.


5. data modules which are the black and white spaces that hold the binary data, black pixel represent 1 and white pixel represent 0.


6. Version information, grid size map, are two small rectangles located next to top right and bottom left corner finer pattern. It tells the scanner which QR code version size is (version from 1 to version 40) However for small QR codes that has versions from 1 to 6, this zone doesn’t exists because the phone can rely on the timing line for counting grid size. But with larger codes, the rows and columns are tightly packed that the phone would need an explicit information telling it how many total pixels to expect before processing starts.


7. Quiet Zone, solid white border, it is the white empty space between the entire QR code and the surroundings of the code, made of at least 4 pixels wide on all sides. It is used to tell the scanner that this is the border when the qr code starts and ends.

For data to be in a qr code, it must be transformed into binary number 0 and 1 for the computer to read it. And for qr code to do this each type of data a letter a number a character anything must be retrieved according to specific worldwide standard.
Here is your text updated with the correct values for the letter R:
For example (aside from binary formula used) letter R in the alphanumeric mode the index table is equal to 27 which in turn transform into 011011. However, the same letter R in byte Mode the Universal ASCII/ISO Table is equal to 82 !! Noting that r is equal to 114 !! 82 is transformed into 01010010.
Hence, if using alphanumeric mode here means using fewer pixels resulting the physical grid is less crowded. So when the scanner read the formate information would see which table is being used and then based on it, it will interpret R.

• Numeric Mode, for numbers 0 to 9 packing each 3 numbers into 10bits


• Alphanumeric Mode, for 45 characters (uppercase A–Z, numbers 0–9, and symbols like $ % * + - . / : and spaces). It packs each two characters into 11 bits


• Byte Mode (8-bit Byte), for universal ASCII/ISO-8859-1 character set mainly including lowercase letters, symbols, emjies all into 8bits


• Kanji Mode, for japanses characters that would pack each one into 13bits


• And ECI Mode (Extended Channel Interpretation), an advanced extension table that tells the scanner to swap out the default alphabet for other global character sets, like Arabic, Cyrillic, or Greek text


Now how many qr code types there are ?
Mainly there are 5 official physical types created by the qr code creator Denso Wave, and an additional 2 functional types in software.

physical types
1. Standard QR Code (Model 1 & 2): classic square code used everywhere, currently model 2 is used
   
2. Micro QR Code: compact version with only one finder pattern which can hold only 35 numerals
   
3. iQR Code: a variant that can be made in rectangle to be printed as long strip, which can hold about 80% more data than a standard code in same space layout
   
4. SQRC (Secure QR Code): looking exactly as a regular qr code, but also it has a hidden encrypted data layer. In which a regular phone scanner would only read public link but a spesicaled scanner with a cryptographic key would read secure internal data like ticket ID
   
5. Frame QR: have physical canvas or white blank space into center or sides of the code. Which allows for an image or a logo or a text to be into the code while maintaining the code functionality
   
functional types

Static QR Codes: data made into the pixel pattern that cannot be altered once made, work offline without any servers

Dynamic QR Codes: data made temporary into the pixel pattern by the hosting company. In which the pixel pattern itself is permanent, but the data written inside it is a permanent, static short URL (like qr.co/x9y). The redirect destination hosted on the server is what is temporary and changeable. When scanned, the link instantly ping a live server and track the scan information like location time and phone type, and dynamically forwards the user to any destination URL, which can be changed at any time in the future

Who created the QR code and how

Qr code was made back in 1994 by the Japanese engineer Masahiro Hara, who created it while he was leading a team of two-persons at Denso Wave (subsidiary company of Toyota Group)
It was created to solve the barcode overload problem. Which in the 1990s the japanses car industry was booming and th factories needed to track 100s of 100s of the parts and they did using barcodes. But barcodes have technical limitations such as it can hold only 20 characters of text (which wasn’t sufficient to store part’s name, serial number, manufacturing location and others) that made it unssufient and that workers needed to print 10 different barcodes on a single box.
Also scanning multiple barcodes on each single box is exhausting and if the scanner misread one barcode, the worker would have to stop and start all over again. Which resulted in huge delays.
Hence, Masahiro Hara was assigned to develop a better scanner, but he knew that creating a better scanner is not the solution, the solution is to create a new type of code. And because many of the worlds best inventions is made in the simplest ways and through the unnoticeable means, while he was playing GO during his lunch break, the idea just came in.
He looked at the grid board covered in black and white stones, and knew that storing data doesn’t need to be read from left to right, it actually can be read in two-dimensional grid matrix so that horizontal and vertical spaces could be used. Hence, this new design would hold over 200 times more information than a barcode could. Along with having finder patterns that would allow workers to scan a 360 degree angle and it would be read instantly. Which results a very fast speed scanning.
And after creating the QR code, Denso Wave made it publicly free without any royalties and licensing fees to be an industry standard, and it did not only in car factories but in almost every technological area now from digital payments to restaurant menus.