2. What is a pixel?
A pixel is the smallest visual element on a
video display screen.
The pixel (a word invented from "picture
element") is the basic unit of programmable
color on a computer display or in a computer
image.
3. The shape of a pixel is rectangle.
. Think of it as a logical - rather than a
physical - unit.
The physical size of a pixel depends on how
you've set the resolution for the display
screen.
Usually we are using high resolution screen
so the pixel size is very very small.
Pixels can be available in different colors.
4. Pixel appears on the screen..:
The specific color that a pixel describes is
some blend of three components of the
color spectrum – RGB (Red,Green,Blue).
The intensity of each pixel is variable; in
color systems, each pixel has typically three
or four dimensions of variability such as red,
green and blue, or cyan, magenta, yellow
and black.
5. Pixel Resolution can is set of two positive
.
integer numbers, where the first number is
the number of pixel columns (width) and
the second is the number of pixel rows
(height), for example as 640 by 480.
At present different types of resolution
screens are available in the market.
The highest Resolution is 1360 by 768.
6. Generating of pixels:
pixels can be generated by CRT(cathode ray
tubes) in two diff techniques:
1. Beam-penetration method
2. Shadow-mask method
7. Beam-penetration method:
In this method the red, green and blue
phosphorus are coated in layers - one
behind the other.
If a low speed beam strikes the CRT, only the
red colored phosphorus is activated, a
slightly accelerated beam would activate
both red and green (because it can penetrate
deeper) and a much more activated one
would add the blue component also.
8. Shadow mask method:
This works, on the principle of combining
the basic colors - Red, green and Blue - in
suitable proportions to get a combination of
different colors.
But it's principle is much more
sophisticated and stable than beam
penetration method.
9. The shadow mask CRT, instead of using
.
one electron gun, uses 3 different guns
placed one by the side of the other to
form a triangle or a "Delta.”
