Welcome
Topic: Pixels
A.M.Meshkatur Rahman
Class: vii
Roll: 07
We often hear the word “Mega Pixel”. But
what is mega pixel? Actually a million of
pixels makes a mega pixel. In 1 kilo pixel
there are 1024 pixels. And In 1 mega
pixel there are 1024 kilo pixels. If we
observe on some digital camera then we
can see its written mega pixels. Pixels are
the things which creates an image.
Description of Mega Pixels
Megapixel
1
Megapixel
1024 kilo pixel
1
Kilo pixel
1024 pixels
1 pixel
Division of pixels
Element of picture
Now we have known a lot about Mega Pixel
now we will know about pixels.
The word ‘pixel’ means picture element in
short ‘pixel’. That is pixels are element of
picture. The pixel is the basic unit of
programmable color on a computer
display or in a computer image. A picture
is not that we see rather it is a number of
colored dots which stands one after
another to form a picture.
Pixels
Pixels
Pixels and Resolutions are almost the same thing.
We often hear that 1366x768 resolution picture.
It means there are 1366 dots in length and 768
dots in breadth in that picture in per inch. Here
this dots are pixels. If we zoom a picture of less
resolution Then we can see that there are many
small dots. These dots are pixels. Screen image
sharpness is sometimes expressed as dpi (dots
per inch). (In this usage, the term dot means
pixel, not dot as in dot pitch.) Dots per inch is
determined by both the physical screen size and
the resolution setting.
Pixels and Resolutions
In the zoomed picture we can see
pixels
The camera at first takes the picture and
cuts it into many small pieces. Each piece
is a small dot or pixel. Each pixel has a
own color of its self. These colors
altogether forms a picture. These pictures
are called digital pictures. But previously
the pictures were not formed like this in a
single lens reflected cameras.
How a digital camera makes a
digital picture
How picture is formed
Now we know that pixels are small dots.
In color image systems, a color is typically
represented by three or four component
intensities such as red, green and blue or
cyan, magenta, yellow and black. There
are 3 basic colors to form a picture. They
are red, green and blue. A pixel contains
all these three colors. We know all color
makes white. So, if the value of the three
colors are 256 then it makes a white dot.
Mixture of color (R,G,B) in pixels
And if the value of red is 256 and other
colors are 0 then it makes red dot. The
others are done in the same way.
However many color display systems use
only one byte-(Limiting the display
system to 256 different colors)
Mixture of color (R,G,B) in pixels
Up to 3 byte of data are allocated for
specifying a pixel color.
 1 byte for each major color component.
 A true color or 24 bit color system uses all
3 bytes.

Space or data management of
pixels
True color
• 24 bit
• (R,G&B)=3byte
256 color
• 8 bit (1 byte)
High color
• 16 bit (2 byte)
COLOR
Now we know about pixels. But how
computer recognizes it?
We have known that the pixel contains
colors. But the computer can not
recognize colors it can only recognize
binary code which are 0 and 1. So
computer recognizes the binary codes and
displays pictures using pixels. The other
scenes or icons on the computer are
displayed in the same way.
How computer recognizes a digital
picture.
The display of Television and Computer also
displays the picture by dividing it into pixels.
We often watch video on Television and
Computer. Question may arise in our mind
that how the computer or TV displays video.
But what is video? It is nothing but a number
of picture displayed in 1 second is called
video. Suppose 24 frames/pictures are
displayed in 1 second.
How do Television and Computer
displays scenes
Pixels
In my presentation I have told you about:
Megapixels
Pixels
Resolution
Formation of Picture
Computer display of pixels
Television display of pixels
Division of Mega Pixels
Data management
How camera takes picture
Picture
Mixture of color
And I hope I have been able to convey my contents
properly.
Thank you…..