Intro to Graphics

What is Graphics?

The field of computing that deals with generating, manipulating, and displaying visual content using computers

• Includes image creation, rendering, animation, modelling, etc

• Covers both 2D (flat) and 3D (volumetric) content.

• Visual: Include examples of rendered 3D objects, GUI design, and video game scenes

Graphics Output

• In the beginning, this was text-only output

• It then developed into 2D graphics output (+ text)

• And finally, into 3D graphics output (+ 2D + text)

• Ultimately, the purpose of a graphics hardware is to accelerate output of graphics to a device

Types

2D graphics are flat images

3D graphics represent objects with depth

Vector graphics use mathematical equations to define shapes, allowing for scaling without quality loss

• It is perfect for scalable designs and clear lines but may not handle complex images well. It used by graphic artists and designers (scalability)

Raster graphics use a grid of pixels, which can become pixelated when resized

• It is best for rich, detailed images but can lose quality when resized. It is best for digital photos and print materials

Display Resolution

• Refers to the number of pixels displayed on the screen horizontally and vertically

• Measured in pixels, determines the sharpness and clarity of a display.

• Higher resolution = more pixels = sharper and more detailed images

What does a Resolution of 1920×1080 mean?

• 1920 pixels horizontally (width)

• 1080 pixels vertically (height)

Why is Resolution Important?

• Image Quality: Higher resolutions give sharper images

• Workspace: More pixels = more screen space (can fit more windows)

• Performance Impact: Higher resolutions require more powerful graphics hardware

• Aspect Ratio: Affects how wide/tall the display appears (e.g., 16:9 is standard widescreen)

Output Devices

• monitors

• connections

Monitors

Display equipment without a built-in RF receiver for TV signals

Often higher-end abilities than TVs

CRT

variable resolution and refresh rate, ‘built in smoothing’, heavy

refresh with a beam of electrons scanning across the inside of the cathode ray tube

LCD/’Flat-Screen’

fixed resolution and scaling, efficient, light

images update all in one go

Connections

• VGA: 15 pin analogue connector; the “external monitor” cable with screws.

• DVI: 25+5 digital + analogue; first digital connector

• HDMI: dominant digital connector, includes extra channels such as audio and data

• DisplayPort: digital, taking over from HDMI?

• USB-C: alternate mode to display video too

Graphics Card/Video Card/Graphics Processing Unit (GPU)

• Hardware component responsible for rendering and displaying images, videos, and animations on your computer monitor

• It works with CPU to process and output visual data

• If use gaming, video editing, three-dimensional (3D) modelling, or other graphic-intensive activities, a dedicated one is essential

• It offloads the graphical processing from CPU, resulting in improved performance and smoother visuals

Are Integrated Graphics in CPUs as powerful as Graphics Cards?

no, if you want the best visuals and performance, a graphics card is necessary

Direct Memory Access (DMA)

• A method for other components in the computer to perform data transfers without the CPU having to shuffle the bits around

• Modern peripherals like graphics cards and disks make a lot of use of this to move lots of data around efficiently

• It is a technology that enables HW devices (disk drives, graphics & network cards) to transfer data directly to and from RAM without involving CPU for each data transfer

• It enhances system performance by offloading data transfer tasks from the CPU, leading to faster data transfer speeds and reduced CPU overhead

• It is useful for devices that need to move large amounts of data quickly and efficiently, such as disk drives, graphics cards, and network cards

DMA Controller

Instead of the CPU handling each data transfer byte by byte, it manages the transfer, allowing the CPU to focus on other tasks

2D Images Colour Modes

Define how colours are represented and stored in an image

Each mode determines:

• How many colour channels are used

• What kind of information each pixel stores

• How much memory the image takes

Storing 2D Images

• Each pixel contains colour information

• It as a grid or table with rows and columns

• Basic Idea:

  • The X-axis (horizontal) = width of the image

  • The Y-axis (vertical) = height of the image

  • Each cell in this 2D grid = one pixel with colour info

• Colour Images (RGB Model)

• Colour images use 3 channels:

  • Red – Green - Blue

• Stored as 3 matrices of the same size

• E.g: A 3×3 colour image (RGB) is:

Palette Based/Indexed Colour Mode

• Stores image pixels not as full colour values, but as indexes (references) to a limited table of colours called a palette

• Each pixel = index to a colour in the palette, not the colour itself

• So instead of storing full RGB values per pixel, we store smaller numbers (indexes) to save memory

3D Graphics

• Digital representations of objects that appear to have depth, in addition to height and width. It just like objects in the real world

• They simulate a three-dimensional space using mathematical models, allowing you to rotate, scale, and view objects from any angle

• The process of drawing them is generally referred to as rendering. Initially, it was done in software

3D vs 2D Graphics

Feature	2D Graphics	3D Graphics
Dimensions	Width + Height	Width + Height + Depth
Realism	Limited	High (with lighting, shading)
Storage	Simple (pixels)	Complex (geometry, textures)
Examples	Logos, icons, photos	Games, simulations, animation

How 3D becomes 2D

• When we create 3D models in computer graphics (e.g., for games, movies, simulations), we eventually need to display them on a 2D screen (like a monitor or phone). This transformation is called Projection

• Using a camera perspective, just like taking a photo of a real 3D object. This 2D result is what we see on screens

NVIDIA GeForce

• A brand of graphics cards designed by NVIDIA

• Dedicated GPUs used in gaming laptops, desktops, and high-performance PCs

  • Released the first GeForce 256 (1999), the world’s first GPU

  • Built for high-quality gaming and real-time rendering

  • Supports ray tracing and AI-enhanced graphics

  • Frequently used in eSports, VR, and game development