Overview of Computer Graphics

Theory of Computation & Computer Graphics — Introduction of Computer Graphics, NEC licence examination syllabus (Nepal Engineering Council).

Computer Graphics Overview: turning numbers into pictures

Every game, every UI, every CGI movie effect ultimately reduces to the same core question: how do you represent a picture as data a CPU can crunch?

Computer graphics is the field concerned with generating, manipulating, and displaying images using a computer. Applications span far wider than games: medical imaging (CT/MRI visualization), CAD/engineering design, movie visual effects, data visualization charts, and the graphical interfaces you interact with every single day.

💡 One-liner: name 3 real-world application domains of computer graphics beyond gaming — CAD, medical imaging, and data visualization are safe, well-known answers.

The one distinction that organises this whole section

Almost everything in this chapter is a variation on a single question: is the picture stored as a grid of dots, or as a list of shapes?

🔲 The same split, four times over

DisplaysRaster (pixel grid) versus vector/random-scan (beam traces the lines).

PrintersInkjet and laser build from dots; plotters draw continuous pen strokes.

File formatsPhotographs store pixels; logos and diagrams store shapes and coordinates.

FontsBitmap fonts store pixels per size; outline fonts store curves and scale to any size.

The trade-off is identical every time. Raster handles arbitrary detail — a photograph is not describable as shapes — but its memory is fixed by resolution, and enlarging it produces visible blocks. Vector stays sharp at any magnification and is compact for line work, but cannot represent a photograph and needs computation before it can be shown.

💡 That is why enlarging a photograph goes blurry while enlarging a company logo stays crisp — the photograph stores pixels that must be invented when stretched, whereas the logo stores instructions that are simply recalculated at the new size.

Why raster won

Raster displays dominate because they can show filled regions and photographs, which vector displays fundamentally cannot. Once memory became cheap enough to hold a full frame buffer, the one advantage vector had — crisp lines without storing every pixel — stopped being worth the limitation.

Syllabus points

Definition and applications of CG

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