Introduction to Computer Graphics Quiz

Introduction to Computer Graphics

• Course: Introduction to Computer Graphics
• Instructor: Tara Qadir
• Semester: 2024-2025, 3rd Stage-first semester
• Department: Computer Department
• College: College of Science
• University: University of Sulymaniah

What is Computer Graphics?

• Computer graphics are created using computers to represent and manipulate image data, aided by specialized software and hardware
• Key functions include:
  • Creation, manipulation, and storage of geometric objects (modelling)
  • Creating images (rendering)
  • Displaying images on screens or hardcopy devices
  • Image processing
  • Other applications: GUI, Haptics, VR/AR

History of Computer Graphics

• 1960s: Limited computer memory (kilobytes), programming languages were assembler, FORTRAN, and Algol. Limited graphics capabilities, like basic function graphs and simple calendars were possible.
• Early 1970s: Advanced graphic systems, like the EVANS and SUTHERLAND picture system, emerged, featuring vector displays with hardware support for clipping and perspective. Xerox PARC introduced 8-bit computers.
• Late 1970s: Commercial personal computers (Apple I and II), the popularization of games like Ping-Pong, and the invention of the laser printer.

Video Display Devices

• Cathode Ray Tubes (CRTs):
  • A beam of electrons creates a picture on a phosphor-coated screen.
  • The phosphor's light fades rapidly, repeated beam sweeps are required to maintain the image.
  • This frequency of image refresh rate is called refresh rate
• Raster-Scan Systems:
  • The electron beam scans across the screen, one row at a time (top to bottom).
  • Beam intensity is adjusted to turn the picture on or off.
  • Stored in a memory area called the refresh buffer/frame buffer
• Random-Scan Systems:
  • The electron beam moves only to the parts of the screen where the image is to be drawn.
  • Also is called vector display, stroke-writing display, or calligraphic display.
• Advantages and Disadvantages of Raster Scan and Random Scan Systems
  • Raster scan systems are good for realistic images, have millions of possible colors, and can display shadow scenes.
  • Random scan systems have high resolution, create smooth lines, and are limited to lines and shapes.

Color CRT Monitors

• Use the RGB color model
• Each pixel consists of three phosphor color dots (RGB)
• Three electron guns—red, green, and blue—are used to produce the colors

Flat-Panel Displays

• Reduced volume, weight, and power consumption compared to CRTs
• Examples: Small TVs, monitors, calculators, pocket video games, laptop computers, advertisement boards in elevators
• Categorized into emissive and non-emissive displays

Liquid Crystal Display (LCD)

• Produce images by passing polarized light through liquid crystal material
• Advantages: bright image, energy-efficient, completely flat screen
• Disadvantages: fixed aspect ratio & resolution, lower contrast, more expensive

Light Emitting Diode (LED)

• A semiconductor device that emits light when current passes through this
• Advantages: intensity control, low operational voltage, capable of handling high temperature
• Disadvantages: more power-consuming than LCD.

Direct View Storage Tube (DVST)

• Stores picture information as charge distribution behind phosphor coated screen
• Using two guns: primary and flood/secondary to display the picture on the screen.

3D Displays

• Also known as stereoscopic display technology
• Used for 3D gaming and 3D TVs, examples include Fog Display, Holographic Display, Retina Display
• Advantages: impressive picture quality, high definition
• Disadvantages: expensive, requires binocular fusion

Input and Hard Copy Devices

• Input Devices: Keyboard, mouse, trackball, joysticks, data gloves, voice systems, light pens, data tablets, touch screens, and 3D input devices
• Output Devices: Printers (raster and vector) and plotters, oscilloscopes.

Output Devices

• Raster Devices: CRTs, LCDs, LEDs, Plasma screens, printers
• Vector Devices: Plotters, oscilloscopes

Applications of Computer Graphics

• Computer graphics user interfaces (GUIs)
• Business presentations
• Cartography
• Weather maps
• Satellite imaging
• Photo enhancement
• Medical imaging
• Engineering drawings
• Typography
• Architecture
• Art
• Training
• Entertainment
• Simulation and modeling.
• Data visualization
• Computer Aided Design (CAD)
• Virtual Reality environments

Review Questions and Discussion

• Explain rasterization
• Compare raster and vector scan displays
• Describe 3D displays and plasma panel displays
• Explain raster scan and refresh rate

Reading List

• "Computer Graphics with OpenGL" (chapters 1 & 2)
• Relevant web resources (URLs provided)