In the process of development, mankind has come to the realization of the need to store and transmit this or that information over distances. In the latter case, its conversion into signals was required. This process is called data encoding. Textual information as well as graphic images can be converted into numbers. About how this can be done, our article will tell.
Distance information
To send a message from the author to the addressee (from source to receiver), three types of transmission systems are most often used:
- courier-postal;
- acoustic (for example, through a loudspeaker);
- based on a particular telecommunication method (wired, radio, optical, radio relay, satellite, fiber optic).
The most common at the moment are transmission systems of the latter type. However, to use them, you must first apply one or another method of encoding information. With the help of numbers in the decimal calculus familiar to modern people, this is extremely difficult to do.
Encryption
Sometimes the content of the message is required to be hidden from strangers. In this case, encryption is used. In this case, various methods of encoding information using numbers can be used.
Binary number system
At the dawn of the computer era, scientists were preoccupied with finding a device that would make it as simple as possible to represent numbers in computers. The question was resolved when Claude Shannon proposed using a binary number system. It has been known since the 17th century, and for its implementation a device with 2 stable states corresponding to a logical “1” and a logical “0” was required. There were plenty of them at that time - from the core, which could be either magnetized or demagnetized, to a transistor that can be either in the open or in the closed state.
The pluses of the binary system of calculus also include the simplicity of calculations that can be performed on numbers represented in binary notation.
How does the conversion of "ordinary" information into a form suitable for processing and storage of computers
Computer binary code is technically implemented by the absence or presence of pulses from microscopic storage elements. These can be:
1. Photo-optical pulses. The surface of any optical disc (DVD, CD or BluRay) consists of a spiral formed from small segments. Each of them is either light or dark in color. When the disk rotates in the drive, the laser focuses on its spiral path. Its reflection hits the photocell. The latter in this case is the receiver of information. Light sections of the spiral reflect light and transmit it to the photocell, dark, on the contrary, absorb light. As a result, information encoded in the track of the disk as dark and light dots comes to the photocell.
2. Magnetic pulses. With their help, information is encoded on the hard drive, inside which is located a rapidly rotating plate. As in the case of optical disks, its entire surface is a spiral, which consists of a sequence of small sections in the amount of several million. Each of them is an element that is capable of accepting one of two states: “magnetized” or “non-magnetized”. They form the binary code of this or that information. "Clarification" of the state of a particular element is carried out by means of a special head that moves along the surface of the plate.
3. Electrical impulses. The main memory of a computer is a microcircuit consisting of millions of small cells "assembled" from microscopic capacitors and transistors. Each of them may contain an electric charge or be uncharged. Combinations of memory cells that are in one of these two possible states form binary code. In all other devices based on storage microcircuits, for example, flash drives, SSD-carriers, etc., information is stored in exactly the same way.
Text Encoding
As already mentioned, one of the types of information conversion for its transmission and storage is encryption. It is used to protect against unauthorized access. Initially, for encryption along with the more primitive, the following methods of encoding information were used:
- By means of the Polybius square, which is a table in which the whole Greek alphabet is inscribed in a certain order. Each letter of the message was replaced by a pair of numbers representing the column and row number.
- By means of an Alberti disk consisting of two concentric circles. They were marked with letters and numbers. They were aligned with each other by rotating the discs.
The modern method of encoding text information in a computer is based on similar principles. For its implementation, each character of the alphabet corresponds to a certain integer. Then it is translated into binary code. Eight bits allow you to encode 256 different characters. They are enough to represent all the letters of the English and Russian languages, including capital letters, signs of arithmetic operations and punctuation, as well as some generally accepted special characters.
At the moment, the ASCII system operates. For her, 2 coding tables are fixed. Of these, the basic one determines values from 0 to 127, and the advanced one is represented by numbers from 128 to 255.
How is encoding a monochrome picture in a computer
Any black-and-white image printed on paper under a magnifying glass looks like a lot of dots, which are usually called a raster. The linear coordinates and brightness of each can be expressed in terms of integers. This means that you can use binary code to rasterize the image. Presently, the representation of monochrome illustrations as a combination of a large number of dots with 256 shades of gray is considered generally accepted. For numerical coding of the brightness of any of them, an eight-bit binary number is required .
Submission of color pictures
The method of encoding information using numbers for such images is somewhat more complicated. For this purpose, the decomposition of the picture into 3 primary colors (green, red and blue) is required beforehand, since as a result of mixing them in certain proportions, any shade perceived by the human eye can be obtained. This method of encoding a picture using numbers using 24 bits is called RGB, or full color (True Color).
If we are talking about printing, then the CMYK system is used. It is based on the idea that each of the main RGB components can be matched with a color that complements it to white. They are cyan, magenta, and yellow. Although there are enough of them, in order to reduce printing costs, they add the fourth component - black. Thus, 32 binary digits are required to represent graphics in the CMYK system, and the mode itself is usually called full color.
Sound presentation
To the question of whether there is a way to encode information using numbers for this, the answer should be yes. However, at the moment, such methods are not considered perfect. These include:
- FM method. It is based on the decomposition of any complex sound into a sequence of elementary harmonic signals of different frequencies, which can be described by a code.
- Tabular-wave method. In pre-compiled tables, samples are stored - samples of sounds for various musical instruments. Numeric codes express the type and model number of the instrument, pitch, intensity and duration of sound, etc.
Now you know that binary coding is one of the common ways of presenting information, which has played a huge role in the development of computer technology.