Now a days, it is easy to store image in mobile phone. Smart phone can store image very easily. Generally, a image is stored with binary number 0 and 1.
Fig 1.1: A black white picture.
First, we are going to discuss about black and white picture. we have to knowledge about pixel. Pixel is a combination of picture and element. Pixel is a smallest element of a picture. A picture is divided into length and width. How pixel is counted? For an example, if we consider length 12 pixel and width 16 pixel. The total pixel of the picture is 12*16=192 pixel.
Fig 1.2: pixel count in image.
pixel count:
If we see the picture 1.2, it is a white and black image. The first block of he image is white so it is counted W and for black it is B. Then the W and B will convert into 8 bit binary number. So, W and B will convert 1010.... type 8 digit number. To know this we have to consider, UNI CODE ( Universal Code) chart.
Fig 1.3: Universal code logo
W in universal code is 57. Now the 57 is converted into a 8 digit binary number. The 8 digit binary number for 57 is 00111001. In this process, a black and white image is stored in phone.
Color Images store process:
A color image is stored according to the three main color called RGB color. RGB color means R=RED,G=GREEN, B=BLUE.
Fig 1.4: RGB color.
RGB Color Range:
RED=0-255
GREEN=0-255
BLUE=0-255
WHITE= (RED=255,GREEN=255,BLUE=255)
BLACK= (RED=0,GREEN=0,BLUE=0)
For other color , the value of RGB color value will change according to the color. The next step is to covert the number into 8 bit binary number.
Why Computer uses binary number to store image?
The answer is because of transistor. Transistor is a electronic devices. Transistor is generally used as a switch. When the transistor is on, the output value is 1, and when it is off the output value is 0.
Fig 1.5:Transistor.
Fig 1.6: Transistor in computer circuit .
For RGB ,the total bit number is 8*3=24 bits. So, at a time 24 transistor will operate at a time.
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