📘 Graphics Systems — Exam Notes
🔹 1. Definition
A Graphics System is a combination of hardware and software used to create, process, store, and display graphical images on a computer.
👉 In simple words:
It is everything (devices + programs) that helps a computer draw and show pictures.
🔹 2. Components of a Graphics System
A graphics system mainly consists of the following parts:
✔️ 2.1 Input Devices
Used to give commands or draw images.
Examples:
- Keyboard
- Mouse
- Light Pen
- Scanner
- Graphics Tablet
👉 These devices help the user interact with graphics.
✔️ 2.2 Output Devices
Used to display or print graphics.
Examples:
- Monitor (CRT, LCD, LED)
- Printer
- Plotter
👉 The monitor is the most common output device.
✔️ 2.3 Central Processing Unit (CPU)
- Controls all operations
- Executes graphics instructions
- Works with memory and devices
✔️ 2.4 Graphics Processing Unit (GPU)
- Specialized processor for graphics
- Handles complex calculations (rendering, shading)
- Makes graphics faster and smoother
✔️ 2.5 Memory (Frame Buffer)
- Stores image data (pixels)
- Each pixel has color information
- Also called Refresh Buffer
✔️ 2.6 Graphics Software
- Programs used to create and edit images
Examples:
- Drawing software
- Animation tools
- CAD software
🔹 3. Working of a Graphics System (Step-by-Step)
-
Input Stage
- User gives commands using input devices
-
Processing Stage
- CPU/GPU processes instructions
- Mathematical calculations are performed
-
Storage Stage
- Image is stored in frame buffer
-
Output Stage
- Image is displayed on the screen
👉 Flow:
Input → Processing → Frame Buffer → Output
🔹 4. Types of Graphics Systems
✔️ 4.1 Raster Scan System
- Displays image using pixels line by line
- Image stored in frame buffer
Features:
- Used in TVs and monitors
- Supports filled shapes and realistic images
✔️ 4.2 Random Scan System (Vector Display)
- Draws lines directly between points
- Does not use pixel grid
Features:
- Used for line drawings
- High precision
- Limited shading
🔹 5. Display Devices in Graphics Systems
✔️ CRT (Cathode Ray Tube)
- Uses electron beam
- Old technology
✔️ LCD (Liquid Crystal Display)
- Flat panel
- Low power consumption
✔️ LED (Light Emitting Diode)
- Improved version of LCD
- Better brightness and contrast
🔹 6. Important Terms
- Frame Buffer: Memory storing pixel data
- Resolution: Number of pixels on screen
- Refresh Rate: Times screen updates per second
- Interactivity: Ability of user to control graphics
🔹 7. Advantages of Graphics Systems
- Fast image processing
- High-quality visuals
- Supports real-time interaction
- Used in many fields (games, CAD, education)
🔹 8. Limitations
- High cost of hardware
- Requires skilled users
- High memory usage
🔹 9. Diagram Description (Important for Exams)
✔️ Block Diagram of Graphics System
Draw the following:
Input Devices → CPU → GPU → Frame Buffer → Output Device
- Label each component clearly
- Show arrows for data flow
📝 Likely Exam Questions
- Define a graphics system.
- Explain the components of a graphics system.
- What is a frame buffer?
- Differentiate between raster scan and random scan systems.
- Explain the working of a graphics system.
- What is the role of GPU in graphics systems?
- Write short notes on input and output devices.
- Describe different display devices.
⚡ Quick Revision Summary
- Graphics System = Hardware + Software for creating images
- Main parts: Input, CPU, GPU, Memory, Output
- Frame Buffer stores pixel data
- Two types: Raster Scan & Random Scan
- Workflow: Input → Process → Store → Display
- GPU improves speed and quality