How To Read Qr Code On Huawei
How to read a QR code online. How to decrypt a QR code online. Decrypting a QR code using online services
There are many special sites that will help you recognize this cipher. Three working services will be described here.
Method 1: Imgonline
To access this site, use the link. Now you can proceed.
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At the bottom of the page, find the inscription in the frame “Specify image in JPEG, GIF, PNG format:”And the button”select a file”. Click on it.
Now find the QR-code you are interested in PNG or JPEG, and click open.
To start the service, click on the button “OK”.
Method 2: Decodeit
To decrypt codes (not necessarily QR), you can use this service by clicking here.
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A list of features will be presented on the main page of the site. We are now interested in the item “Recognize or create a QR code online”. Click on it.
Now you need to click on the button “select a file»And find the code stored on the computer. After that click “Submit”.
Method 3: Zxing
Another good service that is located at this link. Its feature is that it can decrypt more than 10 types of codes, and at the same time only one page is responsible for everything. That is, it is not necessary, as in the previous case, to choose your code type and go to the next pages.
- Find the button “select a file”And click on it. Once you have found the QR code, click on “Submit”.
As you can see, you can recognize a QR code online using special services. This process is absolutely short-lived. So decryption of these codes usually does not cause problems.
Tell your friends on social networks.. Read the QR code / Habr
The article discusses the basic features of QR codes and the method of decoding information without the use of computers.
Illustrations: 14, characters: 8 510.
For those who do not know what a QR code is, there is a good article in English Wikipedia. You can also read the thematic blog on Habré and some good articles on related topics that can be found by searching.
We will consider the solution of the problem of directly reading information from a QR picture using two codes as an example. The information was encoded in the online generator QR Coder.ru.
To understand how to extract data from code, you need to understand the algorithm. There are several standards in the QR code family, their basic principles can be found in the specifications. I will briefly explain: the data that needs to be encoded is divided into blocks depending on the encoding mode. A header is added to the data divided into blocks, indicating the mode and number of blocks. There are also such modes in which a more complex structure of information placement is used. We will not consider these modes due to the fact that manually extracting information from them is impractical. However, based on the principles described below, you can adapt to these modes.
In case of incorrect reading of the data, special codes are used in the QR code, which are able to correct errors in reading. These are the so-called Reed-Solomon codes. We will not consider the principle of calculating codes, as well as correcting errors in information blocks, this is the topic of a separate article. Reed-Solomon (RS) error correction codes are recorded after all information data. This greatly simplifies the task of directly reading information: you can simply read the data without touching the codes. As practice shows, usually the majority of QR matrices are occupied by corrective RS codes.
According to the standard, data with RS-codes are “mixed” before being written to the picture. For these purposes, special masks are used. There are 8 algorithms, among which the best is chosen. The selection criteria are based on a fine system, which can also be read about in the specification.
The “mixed” data is recorded in a special sequence on a template image, where technical information for decoding devices is added. Based on the described algorithm, we can distinguish a scheme for extracting data from a QR code:
Here, a green felt-tip pen highlights the points that will need to be performed when reading the code directly. The remaining items can be omitted due to the fact that the reading is done by a person.
Looking at the pictures, you can see several distinct areas. These areas are used to detect a QR code. These data are not of interest from the point of view of the recorded information, but they need to be crossed out or just remember their location so that they do not interfere. The rest of the code field carries useful information. It can be divided into two parts: system information and data. There is also information about the version of the code. The maximum amount of data that can be written to the code depends on the version of the code. When upgrading, special blocks are added, for example, like here:
On them, you can navigate and understand which version of QR is in front of you. High version codes are also usually impractical to read manually.
The placement of system information is shown in the figure:
System information is duplicated, which can significantly reduce the likelihood of errors during code detection and reading. System information is 15 bits of data, among which the first 5 is useful information, and the remaining 10 is BCH (15,5) code, which allows you to correct errors in system data. RS codes are also classified as BCH codes. Please note that in the figure, two strips of 15 bits do not intersect.
As already mentioned, only the first 5 bits are of interest. Of which 2 bits indicate the level of error correction, and the remaining 3 bits indicate which mask of the 8 available is applied to the data. In the considered QR codes, system information contains:
In addition to the already announced schemes for protecting system information, in addition, a static mask is used that applies to any system information. It has the form: 101010000010010. Since only the first 5 bits are of interest, the mask can be shortened and easy to remember: 10101 (ten. one hundred and one). After applying the operation “exclusive or” (xor) we obtain information.
