2. Welcome Topic: Pixels A.M.Meshkatur Rahman Class: vii Roll: 07

3. Description of Mega Pixels 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.

4. Division of pixels 1024 pixels 1 pixelElement of picture 1024 kilo pixel 1Kilo pixel Megapixel 1

5. Pixels 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.

6. Pixels

7. Pixels and Resolutions 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.

8. In the zoomed picture we can see pixels

9. How a digital camera makes a digital picture 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.

10. How picture is formed

11. Mixture of color (R,G,B) in pixels 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.

12. 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)

13. Mixture of color (R,G,B) in pixels

14. Space or data management of 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.

15. COLOR True color 24 bit (R,G&B)=3byte 256 color 8 bit (1 byte) High color 16 bit (2 byte)

16. How computer recognizes a digital picture. 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.

17. How do Television and Computer displays scenes 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.

18. Pixels

19. Thank you….. 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.