Graphics Systems

📘 Graphics Systems — Exam Notes

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🔹 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.

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🔹 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.

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✔️ 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.

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✔️ 2.3 Central Processing Unit (CPU)

• Controls all operations
• Executes graphics instructions
• Works with memory and devices

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✔️ 2.4 Graphics Processing Unit (GPU)

• Specialized processor for graphics
• Handles complex calculations (rendering, shading)
• Makes graphics faster and smoother

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✔️ 2.5 Memory (Frame Buffer)

• Stores image data (pixels)
• Each pixel has color information
• Also called Refresh Buffer

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✔️ 2.6 Graphics Software

• Programs used to create and edit images

Examples:

• Drawing software
• Animation tools
• CAD software

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🔹 3. Working of a Graphics System (Step-by-Step)

1. Input Stage

   • User gives commands using input devices

2. Processing Stage

   • CPU/GPU processes instructions
   • Mathematical calculations are performed

3. Storage Stage

   • Image is stored in frame buffer

4. Output Stage

   • Image is displayed on the screen

👉 Flow:

Input → Processing → Frame Buffer → Output

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🔹 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

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✔️ 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

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🔹 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

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🔹 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

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🔹 7. Advantages of Graphics Systems

• Fast image processing
• High-quality visuals
• Supports real-time interaction
• Used in many fields (games, CAD, education)

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🔹 8. Limitations

• High cost of hardware
• Requires skilled users
• High memory usage

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🔹 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

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📝 Likely Exam Questions

1. Define a graphics system.
2. Explain the components of a graphics system.
3. What is a frame buffer?
4. Differentiate between raster scan and random scan systems.
5. Explain the working of a graphics system.
6. What is the role of GPU in graphics systems?
7. Write short notes on input and output devices.
8. Describe different display devices.

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⚡ 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

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