In the middle of the last century, in connection with the need for visual presentation of data, coding of graphic information began to emerge. Today we
we can’t imagine a full-fledged computer without a large glossy screen. Modern computer screens and monitors are very different from their predecessors: the image is much more colorful and realistic, the colors are deep and saturated - progress is evident. How is the encoding of graphic information? How is the image displayed on the screen? In order to understand this, it is necessary to study the principle of converting data to digital format and their subsequent output.
As we know,
encoding information is a very time-consuming, but necessary process, since the computer only works with
machine codes. Video, text, drawings - all this in digital format is converted into a combination of zeros and ones. How is the encoding of graphic information?
If you look at the monitor with a tenfold magnification, you can see that it consists of
sets of rectangular or circular cells, grouped in three and called pixels. It turns out that the picture on the screen is actually not whole, it is divided into many tiny particles, arranged in rows. A similar image is called a raster image. Pixels come in certain colors: red, blue, and green (RGB format). Other colors are obtained by mixing them. A pixel can either burn or not (1 or 0). In addition, a particular shade may vary depending on the intensity of the glow, for this additional bits are additionally allocated.
The amount of information allocated for one pixel is called the
color depth (k). The quantity of colors that can be displayed on the screen (n) depends on this value. There is a formula for its definition: n = 2k. Basically, the
graphic information is presented in 8, 16, 24 or 32-bit versions, depending on the PC hardware device.
Modern LCD screens are able to reproduce more than 4 billion colors. For comparison: some thirty or forty years ago, the computer palette consisted of 16 colors!
The image quality on the screen depends not only on the number of colors displayed and
screen resolution, but also on the indicator with the designation "dpi" - the number of pixels per unit of space. The smaller this indicator, the more “grainy” the picture will turn out.
Encoding graphic information also allows you to convert the image to a vector format. A vector image is a way of representing objects using simple geometric shapes: points, lines, curves, polyhedra. Their position on the screen is determined by the coordinates, you can also adjust the color, thickness and drawing lines. Due to its structure, many devices are oriented to work with bitmap images, therefore graphics in a vector representation are usually preliminarily processed by special programs before being displayed on the screen.
Binary coding of graphic information in the form of text is performed on the same principle as the encoding of video and images.