What is coding and decoding? Examples. Methods of encoding and decoding information of numerical, textual and graphic

The operation of electronic computers for data processing has become an important stage in the process of improving management and planning systems. But this method of collecting and processing information is somewhat different from the usual, so requires the transformation of the system to symbols that are understandable to the computer.

What is the coding of information?

Coding data is a mandatory step in the process of collecting and processing information.

As a rule, the code refers to a combination of signs, which corresponds to the transmitted data or some of their qualitative characteristics. And coding is the process of composing an encrypted combination in the form of a list of abbreviations or special symbols that fully convey the original meaning of the message. Encoding is sometimes called encryption, but it's worth knowing that the latter procedure involves protecting data from hacking and reading by third parties.

The purpose of coding is to present information in a convenient and concise format to simplify their transfer and processing on computing devices. Computers only operate on information of a certain form, so it is so important not to forget about this in order to avoid problems. The schematic diagram of data processing includes search, sorting and ordering, and encoding in it occurs at the stage of entering information in the form of a code.

What is information decoding?

The question of what such encoding and decoding can happen to a PC user for various reasons, but in any case it is important to convey the correct information that will allow the user to successfully advance in the flow of information technology further. As you understand, after the process of data processing, the output code is obtained. If such a fragment is decrypted, then the initial information is formed. That is, decoding is the process that is the reverse of encryption.

If during the encoding the data acquire the form of character signals that completely correspond to the transmitted object, then during decoding, the transmitted information or some of its characteristics is taken from the code.

Recipients of encrypted messages may be several, but it is very important that the information fall into the hands of them specifically and not be disclosed before by third parties. Therefore, it is worth studying the processes of encoding and decoding information. They help to exchange confidential information between a group of interlocutors.

Coding and decoding of textual information

When you press the keyboard key, the computer receives a signal in the form of a binary number, the decoding of which can be found in the code table - the internal representation of the characters in the PC. The standard in the whole world is the ASCII table.

However, it is not enough to know what such encoding and decoding is, it is still necessary to understand how the data is located in the computer. For example, to store one character of a binary code, an electronic computer allocates 1 byte, that is, 8 bits. This cell can only take two values: 0 and 1. It turns out that one byte allows you to encrypt 256 different characters, because that's how many combinations can be made. These combinations are a key part of the ASCII table. For example, the letter S is coded as 01010011. When you press it on the keyboard, the data is encoded and decoded, and we get the expected result on the screen.

Half of the ASCII standards table contains codes of digits, control characters and Latin letters. The other part is filled with national signs, pseudographic signs and symbols that are not related to mathematics. It is quite clear that in different countries this part of the table will differ. The digits on input are also converted to a binary computation system according to a standard summary.

Coding numbers

In the binary system , which is actively used by computers, there are only two digits - 0 and 1.

Actions with the resulting numbers of the binary system are studied by binary arithmetic. Most laws of basic mathematical actions for such figures remain relevant.

Examples of encoding and decoding numbers

We suggest considering 2 ways of encoding the number 45. If this number occurs within the text fragment, then each of its components will be encoded, according to the ASCII standards table, 8 bits. The four will turn into 01000011, and the five - in 01010011.

If the number 45 is used for calculations, then a special conversion technique will be used in the eight-bit binary code 001011012, for storage of which only 1 byte will be needed.

Encoding of graphic information

Increasing the monochrome image with a magnifying glass, you will see that it consists of a huge number of small points that form a complete pattern. The individual qualities of each picture and the linear coordinates of any point can be displayed in the form of numbers. Therefore, raster encoding is based on binary code, adapted to display graphic information.

Black-and-white images are combinations of points with different shades of gray, that is, the brightness of any point in the image is determined by eight-bit binary numbers. The principle of decomposition of an arbitrary gradient into basic components is the basis of such a process as the coding of graphic information. The pictures are decoded in the same way, but in the opposite direction.

The decomposition uses three primary colors: green, red and blue, because any natural shade can be obtained by combining these gradients. This coding system is commonly referred to as RGB. If twenty-four binary digits are used to encrypt the graphic, the conversion mode is called full-color.

All the basic colors are compared with the shades that complement the base point, making it white. An additional color is a gradient formed by the sum of other basic tones. Select yellow, purple and blue additional colors.

A similar method of encoding image points is also used in the printing industry. Only here it is accepted to use the fourth color - black. For this reason, the printing system of the transformation is designated by the abbreviation CMYK. This system uses thirty-two binary digits to represent images.

The methods of encoding and decoding information assume the use of different technologies, depending on the type of input data. For example, the method of encryption of graphic images with 16-bit binary codes is called High Color. This technology makes it possible to transmit to the screen as many as two hundred and fifty six shades. By decreasing the number of binary bits used to encrypt the points of the graphic image, you automatically reduce the amount needed to temporarily store information. This method of data coding is usually called an index method.

Coding sound information

Now that we have considered what encoding and decoding, and the methods that underlie this process, it is worth considering the issue of encoding audio data.

Sound information can be represented as elementary units and pauses between each pair. Each signal is converted and stored in the computer's memory. Sounds are output using a speech synthesizer that uses encrypted combinations stored in the PC's memory.

As for human speech, it is much more difficult to encode, because it has a variety of shades, and the computer has to compare each phrase with a standard, previously recorded in his memory. Recognition will occur only when the spoken word is found in the dictionary.

Coding information in binary code

There are various methods for implementing such a procedure as the encoding of numerical, textual and graphic information. Data decoding is usually done by reverse engineering.

When coding numbers, even the purpose with which the figure was entered into the system is taken into account: for arithmetic calculations or simply for output. All data encoded in the binary system is encrypted with units and tokens. These symbols are also called bits. This method of encoding is the most popular, because it is easiest to organize in the technological plan: the presence of the signal is 1, the absence is 0. The binary encryption has only one drawback - it is the length of combinations of symbols. But from a technical point of view it's easier to manage a bunch of simple, similar components, than a small number of more complex ones.

Advantages of binary coding

• This form of information representation is suitable for various types of information.
• When transmitting data, there are no errors.
• A PC is much easier to process data encoded in this way.
• Devices with two states are required.

Disadvantages of binary coding

• A long code length that somewhat slows down their processing.
• The complexity of the perception of binary combinations by a person without special education or training.

Conclusion

After reading this article, you were able to find out what encoding and decoding is and what it is used for. It can be concluded that the methods used for data conversion depend entirely on the type of information. It can be not only text, but also numbers, images and sound.

Coding of various information allows to unify the form of its representation, that is, to make it the same type, which significantly speeds up the processing and automation of data in the future use.

In electronic computers, the principles of standard binary coding are most often used, which converts the original form of information representation into a format more convenient for storage and further processing. When decoding, all processes occur in the reverse order.