Technology

From Pixels to Motion: Computer Graphics and Multimedia Explained

December 24, 2025

Computer Graphics and Multimedia – Complete Study Notes

1.Graphics Hardware – Primitives

Computer graphics hardware consists of physical devices used to create, process, store, and display graphical images.Graphics primitives are the basic building blocks of images such as points,lines,curves,and polygons which are combined to form complex graphics.

Display Devices – Refresh Cathode Ray Tube (CRT)

The Cathode Ray Tube is an early display device that uses an electron gun to emit a beam of electrons which strike a phosphor-coated screen to produce images.The beam scans the screen repeatedly to refresh the image and avoid flickering.

Raster Scan Display

Raster scan displays generate images by scanning the screen line by line from top to bottom.Pixel intensity values are stored in a frame buffer and refreshed continuously to display graphics accurately.

Plasma Display

Plasma displays consist of tiny gas-filled cells that emit ultraviolet light when electrically charged,producing visible colors.These displays are known for high brightness and contrast and are commonly used for large screens.

Liquid Crystal Display (LCD)

LCD technology uses liquid crystals to control light passing through them with the help of a backlight.LCDs are thin,lightweight,consume less power,and are widely used in laptops,monitors,and mobile devices.

Plotters and Printers

Plotters are output devices used for producing large vector drawings such as maps and engineering designs,while printers generate hard copies of images and text using inkjet or laser technology.

PCI / PCIe Graphics Cards

Graphics cards are dedicated hardware components that process graphical data and accelerate rendering operations.PCIe graphics cards provide high-speed data transfer between the CPU and GPU for improved performance.

Input Devices

Input devices are used to interact with graphics systems and include keyboard for text input,trackball and mouse for pointer movement,joystick for directional control,pen tablet digitizer for drawing and design,and digital cameras for capturing images.


2.Basic Mathematical Concepts for Computer Graphics

Matrices and Determinants – Definitions and Operations

Matrices are rectangular arrays of numbers used to represent transformations such as translation,rotation,and scaling.Determinants help in understanding matrix properties like invertibility and scaling effects.

Matrix Operations in Graphics Transformations

Matrix operations such as addition,subtraction,multiplication,transpose,and inverse are essential for performing graphical transformations and combining multiple transformations efficiently.

Vectors – Definition and Coordinate System Representation

Vectors represent both magnitude and direction and are used to define points,directions,velocities,and surface normals in computer graphics using coordinate systems.

Drawing Algorithms – DDA Algorithm

The Digital Differential Analyzer algorithm is a line drawing algorithm that calculates intermediate points using incremental floating-point arithmetic to draw straight lines between two endpoints.

Bresenham’s Line Drawing Algorithm

Bresenham’s algorithm efficiently draws straight lines using integer arithmetic,making it faster and more suitable for raster displays compared to DDA.

Bresenham’s Circle Generation Algorithm

This algorithm draws circles by exploiting symmetry and incremental calculations,reducing computation and improving rendering speed.


3.Graphics Operations – Clipping and Filling

Clipping Concepts – Point,Line,and Polygon Clipping

Clipping is the process of removing portions of objects that lie outside the viewing region to improve rendering efficiency and ensure correct display.

Sutherland–Cohen Line Clipping Algorithm

This algorithm assigns region codes to line endpoints and uses logical operations to determine whether a line is fully visible,invisible,or partially visible.

Midpoint Subdivision Algorithm

The midpoint subdivision algorithm recursively divides a line segment until visible portions are identified within the clipping window.

Filling Techniques – Flood Fill Algorithm

The flood fill algorithm fills connected regions with a specified color until a boundary or different color is encountered.

Boundary Fill Algorithm

The boundary fill algorithm fills an area until it reaches a defined boundary color and is commonly used in interactive painting applications.

Scan-Line Polygon Fill Algorithm

This algorithm fills polygons by scanning horizontal lines across the shape and computing intersections with polygon edges.


4.2D and 3D Transformations & Projections

2D Geometrical Transformations – Translation,Scaling,Rotation,Reflection,Shear

Two-dimensional transformations modify object position,size,orientation,and shape using mathematical operations applied to coordinates.

Matrix Representation and Homogeneous Coordinates

Homogeneous coordinates use an additional dimension to simplify transformation calculations and allow multiple transformations to be combined using matrix multiplication.

Composite Transformations and Coordinate Transformations

Composite transformations apply multiple transformations sequentially by multiplying their corresponding matrices into a single matrix.

3D Geometrical Transformations – Representation of Points and Objects

Three-dimensional transformations operate on objects represented in x,y,and z coordinates and are used in modeling real-world scenes.

3D Scaling,Shearing,Rotation,Reflection,and Translation

These transformations modify 3D objects by changing size,orientation,position,and shape using transformation matrices.

Multiple Transformations and Rotation about Axis Parallel to Coordinate Axis

Complex transformations involve applying multiple operations and rotating objects around axes parallel to coordinate axes.

Projections – Parallel,Perspective,and Isometric

Projection techniques convert 3D objects into 2D representations with parallel projection preserving dimensions and perspective projection creating depth realism.

Viewpoints and Viewing Transformations

Viewing transformations define the observer’s position,orientation,and viewing direction in a graphical scene.


5.Object Representation

Polygon Surfaces and Quadric Surfaces

Polygon surfaces approximate objects using flat faces,while quadric surfaces represent smooth curved shapes such as spheres and cylinders.

Spline Representations – Hermite Curve,Bezier Curve,and B-Spline Curve

Spline curves are mathematical representations used to create smooth and flexible shapes in modeling and animation.

Bezier and B-Spline Surfaces

These surfaces extend spline concepts to two dimensions and are widely used in CAD systems and surface modeling.

Basic Illumination Models

Illumination models describe how light interacts with surfaces using ambient,diffuse,and specular components.

Shading Algorithms and Techniques

Shading techniques such as flat shading,Gouraud shading,and Phong shading determine surface color and realism.


6.Multimedia Systems

Introduction to Multimedia – Definition and Components

Multimedia integrates text,graphics,audio,video,and animation to create interactive and engaging digital content.

Multimedia Objects – Text,Graphics,Animation,Audio,Images,and Video

Multimedia objects are individual elements combined to form complete multimedia presentations.

Definition and Concept of Hypertext and Hypermedia

Hypertext links text documents while hypermedia extends linking to multimedia content.

Components of a Multimedia System

A multimedia system includes hardware,software,storage devices,and communication networks.

Image and Graphics – Vector vs Bitmap Graphics

Vector graphics use mathematical equations while bitmap graphics represent images as pixels.

Image Creation and Editing Concepts

Image editing involves creating shapes,managing layers,drawing lines and curves,transforming objects,adjusting perspective,applying gradients,and modifying image properties.

Image Adjustments and Tools

Image adjustments include levels,auto levels,clone stamp,healing brush,feather effects,cropping,and resizing.

Audio Systems and Sound Concepts

Audio systems consist of microphones,sound cards,and speakers and involve digitization of sound using sampling frequency and bandwidth.

Audio File Formats and MIDI

Common audio formats include WAV,MP3,AAC,and MIDI where MIDI stores musical instructions instead of sound waves.

Video and Animation

Video consists of rapidly displayed image frames while animation creates motion using frame-by-frame techniques,tweening,and morphing.

MPEG Standards

MPEG standards such as MPEG-1,MPEG-2,MPEG-4,MPEG-7,and MPEG-21 define compression and multimedia representation techniques.

Animation Principles

Animation principles such as timing,anticipation,and smooth transitions enhance realism and visual appeal.




Written by Sourav Sahu


Educational Content Creator | SS WebTechIO



Sourav Sahu is an educational content creator and the founder of SS WebTechIO.
He creates structured, syllabus-based learning resources in computer graphics,
multimedia systems, programming, and information technology for students and exam aspirants.



View Author Profile