anthony morris
🧠

2020-09-21

astr-1101

cpsc-1480

  • Chapter 3 reading
    • Addressing on networks
  • Lecture outcomes
    • Distinguish analog vs digital
    • Explain compression and calculate compression ratios
    • Do text compression
    • Explain the nature of sound
    • Explain how RGB define color
    • Distinguish between raster/vector graphics Todo
    • Explain temporal/spatial video compression
  • Data
    • Values or facts
    • Can be unstructured
    • Lack context
    • All data is stored as binary digits (bits)
  • Information
    • Data organized and/or processed in a way that is useful in solving some kind of problem
  • Analog vs digital
    • Analog --> infinite
      • Continuous representation
      • Analogous to actual information it represents
    • Digital --> finite
      • Computers are limited by memory
      • Represent enough of the world to satisfy computational needs and our senses
      • Discrete representation
        • We can only represent data with 0s and 1s
      • Breaks up information in separate elements
  • Electronic signals
    • Analog signal continually fluctuates in voltage
    • Digital signal has only high or low state
      • Corresponds to two binary digits
    • All electronic signals degrade as the move
    • Voltage signal fluctuates due to environmental effects
  • Audio information
    • Digitized by:
      • Sampling --> periodically measure the voltage
        • 40,000 times per second
      • Quantization --> represent voltage as a number using finite number of bits
  • Color depth
    • HiColor
      • 16 bits
    • TrueColor
      • 24 bits