Payment code, business card code, health code, campus code, ride-sharing code… QR codes have penetrated every corner of Chinese life.
According to the WeChat team, during the novel coronavirus epidemic, as many as 140 billion QR codes were used on WeChat alone.
Will the QR codes that drive a large part of China's economy be used up?
Tencent gave an answer today, and the answer is: yes. But there is no need to worry.
Because the size of the QR code is finite, then the number of QR codes is finite. But it takes a long, long, long time to sweep through all the QR codes.
There are now 40 official versions of the QR code (QR code is a matrix QR code symbol developed by Denso in September 1994). From Version1-40, the minimum is 21*21 and the maximum is 177*177 matrix.
Among them, the WeChat business card is the 37×37 matrix specification and the WeChat payment code is the 25×25 matrix specification. For ease of understanding, we use squares as matrix units.
How to calculate the QR code of the 37×37 matrix and the number of QR codes generated in each matrix?
The following quadrangles, each with two color variations, how many shapes can be combined in one quadrangle?
Answer: two colors in one grid, that's two possibilities, two squares are four possibilities, three squares are eight possibilities, and four squares are 16 possibilities. So, the quadrangle is able to make up 2^4, for a total of 16 figures.
25X25 WeChat payment code
Each row has 25 squares for a total of 25 rows, leaving 478 squares after removing squares for positioning, redundant error correction squares, etc. In binary, each square has only two options, black or white, so 478 small squares could theoretically combine 2^478 2D codes in total.
That is, a 25X25 size QR code can be generated for a total number of: 780437137578998057845399307448291576437149535666242787714789239906342934704941405030076525765872992789956732780351655723861993919822071326572544.
Based on the number of 140 billion QR codes during the epidemic, it is assumed that WeChat will use 600 billion QR codes a year. How many years does it take for a microcredit to drop the 25X25 size to produce a QR code?
Let's do the math: 2^478/600 billion = 1.301 x 10^132 years
There is no shortage of Chinese 2D codes, and they are used by everyone in the world, which equals: 1.301 x 10^132 / 5 = 2.602 x 10^131 years.
Earlier this month, Tencent WeChat and the China ICT Institute jointly released the 2019-2020 WeChat Employment Impact Report, where employment related to the WeChat ecology was disclosed.
In 2019, the size of the economy around WeChat QR codes reached 8.58 trillion yuan, or about 9 percent of China's GDP (99.0865 trillion yuan), the report said.
The report shows that WeChat created 29.63 million jobs in 2019, of which 26.01 million were directly created, up 16% year-on-year and 22% year-on-year since 2014. WeChat indirectly created 3.62 million jobs.
