TP3

• Bitmap Image

  1. Bitmap image are stored as a series of tiny dots called pixel.
  2. Bitmap graphics can be edited by erasing or changing the colour of individual pixel or program such as adobe photoshop.
  3. Bitmap image tend to be larger than vector image.
  4. Bitmap image need more space.
  5. Bitmap image is less scalable.
  6. It is costless
  7. Resolution dependent.
  8. Loses quality when it is resized.
  9. Scan conversation are required.
• Vector Image:

  1. Vector image are not based on pixel pattern. It is mainly based on the geometrical and mathematical formula.
  2. Vector image can be edited by manipulating the lines and curves that make up the image.
  3. Vector image tend to be smaller than bitmap image.
  4. Vector image need less space
  5. Vector image is more scalable
  6. Vector image is more flexible
  7. Resolution dependent
  8. Doesn't lose quality when resized.
  9. Scan conversation are not required.
• In a colour image we need lots of 'bits' (typically 24) to store the colour values of each pixel.
• In a simple black and white image, a bitmap just needs to know if a pixel is 'on' or 'off', which can be stored as 1 or 0.
• • Electronic circuits in computers, many new memories and controlling devices are made up of thousands of logic gates.
  • Logic gates take binary inputs and produce a binary output.
  • Several logic gates combines together form a Logic circuit and these circuits are designed to carry a specific function.
• Logic gates

  • The building blocks used to create digital circuits are logic gates.
  • There are three elementary logic gates and a range of other simple gates.
  • Each gate has its own logic symbol which allows complex functions to be represented by a logic gate.
• Not gate

  The output, is 1 if: The input, is 0

  X= NOT A --> Logic expression

  X= ¯A --> Boolean expression

  
• AND gate

  The output, is 1 if: Both inputs, are 1

  X=A AND B --> logic expression

  X= A . B --> Boolean expression

  
• OR gate

  The output, is 1 if: either input, is 1

  X= A OR B --> logic expression

  X= A + B --> Boolean expression

  
• NAND gate

  The output X, is 1 if: Input A and Input B are NOT both 1.

  X= A NAND B --> Logic expression

  X= ¯A . ¯B --> Boolean expression

  
• NOR gate

  The output Q, is 1 if: Neither input A not input B is 1.

  X= A NOR B --> logic expression

  X=¯A+¯B --> Boolean expression.

  
• Which Logic gate does this belong to?

  Nor gate

  
• Which Logic gate does this belong to?

  NAND gate

  
• Which Logic gate does this belong to?

  NOT gate

  
• Which Logic gate does this belong to?

  OR gate

  
• Which Logic gate does this belong to?

  AND gate

  
• ASCII

  • Most computers use ASCII for storing characters.
  • Initially ASCII uses 7 bits and can represent up to 128 different characters.
  • Later the extended ASCII version uses all 8 bits and can represent up to 256 characters.
• Unicode

  • Unicode is an international standard character set which uses 16 bits to represent a character.
  • The goal is to specify a code matching every character needed by every written human language, including Japanese and Arabic.
  • It aims to be understood by all computer platforms. (by all hardware and every operating system.)
  • The first 256 Unicode characters are identical of ASCII.