Theory
Pictures made by computers, everywhere
Look at almost any screen and you are seeing computer graphics: a chart in a report, a character in a game, a flight simulator, an enhanced medical scan. Computer graphics is the field of creating and manipulating images with a computer, and it touches an enormous range of human activity.
This subject will take you down to how a single line is drawn pixel by pixel. But first, this opening lesson surveys where computer graphics is used, its major application areas, so you appreciate the breadth of what the low-level techniques ultimately serve.
At a glance
| Area | Examples |
|---|---|
| Presentation graphics | Charts, graphs, and diagrams that visualise data in reports |
| Entertainment | Games, films, animation, special effects, virtual reality |
| Education and training | Simulators (flight, driving, surgery), interactive models |
| Image processing | Enhancing, restoring, and analysing images (e.g. medical scans) |
Theory
From data to pictures, and pictures to insight
Presentation graphics turns numbers into visuals, a sales chart, a pie graph, so people grasp data at a glance. Entertainment is the most visible area: games, animated films, and effects are all computer graphics, often stunningly realistic.
Education and training uses graphics for simulation: a flight simulator lets a pilot practise safely, and interactive models teach concepts vividly. Image processing is a close cousin: it works on existing images, enhancing a blurry photo, sharpening a medical scan, extracting information. (A useful distinction: graphics usually creates an image from data, while image processing usually operates on an image that already exists.) Together these show graphics as both a way to present and a way to understand.
Quiz
A flight simulator that lets trainee pilots practise safely on the ground is an example of computer graphics used in which area?
- Presentation graphics, because it shows data
- Education and training, because it simulates a real situation for learning and practice
- Image processing, because it enhances photos
- It is not computer graphics at all
Show the answer
Education and training, because it simulates a real situation for learning and practice
A flight simulator is computer graphics in education and training: it creates a realistic, interactive simulation so trainees can learn and practise safely before doing the real thing. Option A, presentation graphics, is about visualising DATA as charts and graphs, not simulating an experience. Option C, image processing, operates on existing images (enhancing, analysing), whereas a simulator generates an interactive world. Option D is wrong: rendering a realistic, interactive 3D environment is very much computer graphics. Simulation for learning and practice is a core education-and-training application of graphics.
Think first
What is the difference between computer graphics and image processing?
Both deal with images. How do computer graphics and image processing differ in direction? Then tap.
Show the answer
The classic distinction is the DIRECTION of the work: computer graphics usually goes from DATA to an IMAGE, while image processing usually goes from an IMAGE to information or a modified image. In computer GRAPHICS, you start with a description or data, the coordinates of a shape, a 3D model, the numbers behind a chart, and the computer SYNTHESISES a picture from it: it computes which pixels to light up to draw a line, render a scene, or plot a graph. The input is data; the output is a fresh image. In image PROCESSING, you start with an image that ALREADY EXISTS (a photo, a scan, a video frame) and you OPERATE on it: sharpening it, removing noise, adjusting brightness, detecting edges, recognising objects, or extracting measurements. The input is an image; the output is an improved image or extracted information. So one CREATES images from data, the other ANALYSES or transforms existing images. They are closely related and often used together (a medical system might process a scan and then render a graphic overlay), and both live under the broad umbrella of visual computing, but knowing which direction you are working in clarifies which techniques apply. This subject is mostly about computer graphics in the first sense, computing images from geometric data, which is why it starts with how a line is drawn pixel by pixel from its endpoints. Data to image is graphics; image to insight is processing.
Summary
Key takeaways
- Computer graphics is creating and manipulating images with a computer, used across many fields.
- Presentation graphics visualises data as charts, graphs, and diagrams for reports.
- Entertainment covers games, films, animation, special effects, and virtual reality.
- Education and training uses graphics for simulators (flight, driving, surgery) and interactive learning models.
- Image processing enhances, restores, and analyses existing images (like medical scans).
- Graphics usually creates an image from data; image processing usually operates on an existing image.
- Memory hook: present data, entertain, train with simulators, process images; graphics makes pictures from data.