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ДАСТУРИЙ ҚЎМИТА ТАРКИБИ:
Рахматуллаев М.А.
АКТ кафедраси профессори;
Ганиев А.А.
АХТ кафедраси мудири;
Джуманов Ж.Х.
КТ кафедраси мудири;
Муминов Б.Б.
ИА кафедраси мудири;
Мухаммадиев А.Ш.
АТ кафедраси мудири;
Давронбеков Д.А.
МАТ кафедраси профессори;
Мадаминов Х.Х.
МАТ кафедраси мудири;
Исмаилова Г.Ф.
М ва М кафедраси мудири;
Нишанбаев Т.Н.
МУТ ва Т кафедраси профессори;
Акбаралиев Б.Б.
ДИ факультети декани;
Кучкаров Т.А.
КТ кафедраси доценти
Позилова Ш.Х.
АТТ кафедраси доценти;
Хусанов Ш.А.
АТМ бошлиғи;
Назаров Ғ.А.
МХ матбуот котиби;
Ульянова Н.В.
ИПКТ ва ИТИ бўлим бошлиғи;
Алламуратова З.Ж
котиба.
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5-ШЎЪБА
РАДИОТЕХНИКА, ТЕЛЕРАДИОЭШИТТИРИШ ВА
МОБИЛ АЛОҚА ТЕХНОЛОГИЯЛАРИ
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TELEVISION OF HIGH QUALITY
F.F.Sayfutdinov (student, TUIT named after Muhammad al-Khwarizmi)
U.F. Akramov (student, TUIT named after Muhammad al-Khwarizmi)
The International Advisory Committee on Radio communication (CCIR), the
representatives of Japan made a proposal to study issues relating to television high-
quality image clarity as a new research program. As a result, it was decided to
include as a subject of study in question 1/11 - color TV standards. This issue has
become a new subject of discussion of the research program itself.
The issue of high-quality television is mature enough, not only in Japan, but
also reflects the wishes of all other countries. On the other hand, modern television
does not constitute a fully completed form of TV broadcasting.
The issue of high-quality television is mature enough, not only in Japan, but
also reflects the wishes of all other countries. On the other hand, modern television
does not constitute a fully completed form of TV broadcasting.
Successfully implemented the transition from black and white television to
color, moreover, work is also successfully carried out in the direction of obtaining
a large-scale television. There, no less than the quality of the television images
below, according to the definition of the image.
First of all, on the clarity of the image. In other favorable conditions of
observation and stable parameters of the reproduced image in the existing TV
standard violation, mixing of colors produces an unpleasant impression.
The small size of the TV screen limits the viewer; the majestic steppes
practiced in the cinema are lost. When the screen of a small-sized observer does
not perceive space in that greatness as the director wanted and there is no
emotional impact. In a small screen, you cannot display a large number of actions.
Against their will, negative emotions arise in this case.
To overcome the above drawback, it is necessary to study the issue of
perception related to the television image.
The process of vision.The person most clearly sees the shoo part of the image
formed on the retina, which is placed on the central fovea, i.e. in the near corner of
the field of view about 20 somewhat worse, he sees the shoo part of the image,
which is placed on the rest of the yellow spot as far as the removal of the image
from the yellow spot, it is perceived less clearly, and on the periphery of the retina
is very indistinct, here only the variable brightness is practically felt.
However, practice shows that a person perceives sharply objects that occupy a
significantly large angular field of view. This is due to the fact that when you look
at the space, the person constantly mixes the optical axes of the eyes, as if looking
at all the space interesting for him. Thus, he considers the object in parts and gets
the impression of a sharp image of objects located in a large field of view.
The issue requiring research: The TV image is restored according to the
elemental law of the sweep. How information should be oriented to perceive how
to match the speed of the survey with the sweep speed. It may be necessary to
change the clarity of the image according to a certain law.
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Less studied color perception; there are several theories of color vision.
According to these theories, it is assumed that there are some elements in the eye
that are pitiful for the perception of individual colors, but these elements have not
yet been experimentally discovered.
The main characteristics of vision, which play an especially important role in
the visual perception of TV images, include the following:
- contrast sensitivity of the eye,
- Perception of colors,
- Adaptation of the eye,
- resolving power (visual acuity),
- Speed of visual perception,
- Perception of flickering.
Sensitivity of the eye. Table 1
According to Petrov's data, the contrast sensitivity of the middle eye
where
– is the threshold brightness difference.
When the brightness of the background is
А=1
When the brightness of the background is increased to 12,7
А – it
increases from 1 to 55
When the brightness of the background increases from 12,7 to 637
А very little
With a background brightness of 637
А=58,8.
With further increase in the brightness of the background, A decreases to
28,9.
The data were obtained with the angular dimensions of the objects
. With
the smallest size of subjects, the contrast sensitivity of the eye is smaller than
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indicated in the table. When the angular dimensions are increased above
, it
practically does not change.
We have a greater contrast sensitivity of the eyes of the estates in the central
fossa and, as we move away from the central fossa, it decreases, reaching the
periphery of the shell to a value tens of times smaller.
Contrast sensitivity to a significant extent depends on the level of brightness,
which will adapt the eye at the time of observation.
The correctness of visual perception of colors depends on the level of
brightness. The best perception of colors occurs at medium brightness, with small
colors perceived with distortion. At excessively high brightness, the perceived
colors lose their saturation (as if diluted with white color).
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