4.3

• photo storage;

  brain - The brain receives and sends signals as electrical impulses

  camera - films rely on chemicals to store information. Over time these chemicals can react & change, so the image may also change

  digital - numbers
• digital imaging - process of creating an image using a computer
• pixels - Short for Picture element; individual element of a digital image

  • each is assigned coordinates
  • each is assigned a value (colour)
  • these numbers are stored on computers
• resolution - number of pixels per unit area of a Digital image

  more pixels = better quality
• CCD - charged coupled device

  • grid similar to graph paper, when light falls on a square it creates electricity, the image is converted to numbers
  • after this, it can be stored
• • Satellites have cameras which capture images, turn them into digital information and beam that information to computers here on earth