Types of graphics software

Computer graphics are pictures created, changed or processed by computers. There are two categories.


1. Bitmapped graphics represent images as bitmaps;
they are stored as pixels and can become a bit distorted when they are
manipulated. The density of dots, known as the resolution and expressed in dots
per inch, determines how sharp the image is.

2. Vector graphics represent images as mathematical formulae, so they can be changed or scaled without losing quality. They are ideal for high-resolution output.

There are different types of graphics software.

• Image manipulation programs let you edit your favorite images. For example, you can scan a picture into your PC or transfer a photo from your camera and then add different effects, or filters.

• Painting and drawing programs, also called illustration packages, offer facilities for freehand drawing, with a wide choice of pens and brushes, colors and patterns. One example is Windows Paint.

• Business graphics programs, also called presentation software, let you create pie charts, bar charts and line graphs of all kinds for slide shows and reports. You can import data from a database or spreadsheet to generate the graphs.

• Computer-aided design (CAD) is used by engineers and architects to design everything from cars and planes to buildings and furniture. First they make a wireframe, a drawing with edges and contour lines. Then if they want to color the objects and add texture, they create a surface for the object; this is called ‘filling the surface’. Finally, the design is rendered to make the object look realistic.
Rendering is a process that adds realism to graphics by using shading, light sources and reflections.

• Desktop publishing (DTP) is based around a page layout program, which lets you import text from a word processor, clip-art (ready-made pictures) from graphics packages, and images from scanners or cameras, and arrange them all on a page. It is used to design and publish books, newspapers, posters, advertisements, etc.

• Digital art, or computer art, is done with applets that use mathematical formulae to create beautiful bright shapes called fractals. A fractal is a geometrical figure with special properties, e.g. the Koch snowflake or the Mandelbrot set. Fractals can also be used to model read objects like clouds, coastlines or landscapes.

• Computer animation used graphics programs (e.g. digital cartooning systems) to create or edit moving pictures. Each image in a sequence of images is called a ‘frame’.

• Geographic information systems (GIS) allow cartographers to create detailed maps.