Computer Graphics Unit Notes

Introduction to Computer Graphics

  • Definition: A field that focuses on the creation, manipulation, storage, and display of visual objects using computers.

  • Relevance: Ubiquitous in modern life and serves as a key area for research.

Objectives of the Course

  • Goal: To teach the design of graphics systems for economical image production.

  • Scope: Offers courses at both undergraduate and postgraduate levels.

  • Current Trends: Incorporating more physics and chemistry into 3D graphics.

Classification of Computer Graphics

  • Based on Interaction:

    • Interactive graphics

    • Non-interactive graphics

  • Based on Dimension:

    • 2D graphics

    • 3D graphics

Components of Graphics Systems

  • Input Devices: Mouse, keyboard, joystick, touchscreen, trackball.

  • Hardcopy Devices: Printers, plotters.

  • Display Devices: Color monitors.

  • Processing Units:

    • CPU

    • System Memory

    • Frame Buffer

    • Graphics Controller/Coprocessor

  • Software: Graphics library and graphics software.

Conceptual Framework of Computer Graphics

  • Layers of Functionality:

    • Application Model

    • Application Program

    • Graphics Application Software

    • Graphics Monitor

Typical Applications of Computer Graphics

  • User Interface Elements: Menus, icons, cursors, dialog boxes, scroll bars.

  • Specific Fields:

    • Computer-Aided Design (CAD)

    • Presentation Graphics

    • Computer Art

    • Entertainment

    • Movies, TV, Video Games

    • Education and Training

    • Visualization

    • Image Processing

    • Simulators & Virtual Reality

    • Graphical User Interfaces (GUIs)

Detailed Applications

1. Computer-Aided Design (CAD)

  • Uses: Design in architecture, engineering, manufacturing.

  • Features: Wireframe outlines, multi-window environments, and realistic animations.

2. Presentation Graphics

  • Functions: Create slides, charts, and graphs for reports.

  • Types of Visualizations: Bar charts, line charts, pie charts.

3. Computer Art

  • Tools: Paint packages, CAD software, and animation tools.

  • Applications: Digital paintings, cartoon animations, logo design.

4. Entertainment

  • Domains: Film and television industry, video games focus on interactivity.

5. Education and Training

  • Use Cases: Simulations and training models for professionals.

6. Visualization

  • Fields: Scientific visualization, business data representation.

7. Image Processing

  • Applications: Techniques to modify photographs, application in medical imaging, etc.

8. Graphical User Interfaces (GUIs)

  • Components: Menus, icons to ease user interaction.

Graphics Packages and Standards

  • Types of Libraries: Core graphics, GKS, SRGP, PHIGS, OpenGL.

Overview of Video Display Devices

  • CRT Technologies: Different types of cathode ray tubes and their functionalities including color monitors and refresh rates.

Line Drawing Algorithms

Basic Concepts

  • Definition: A line connects two points and can be mathematically represented using its slope.

Algorithms

  • Digital Differential Analyzer (DDA): A method of rasterizing lines by determining pixel positions.

  • Bresenham's Line Algorithm: Efficient decision-making to plot lines based on endpoints.

Circle Drawing Algorithms

  • Definition: A circle is defined by points equidistant from the center.

  • Midpoint Circle Algorithm: Determines points on a circle using symmetry and decision parameters to optimize plotting.

Conclusion

  • Computer graphics is an extensive field with a multitude of applications in various industries, hinging on the basics of graphic design, mathematical calculations, and system architectures. The algorithms learnt are the foundation for rendering visualizations effectively in modern computing systems.