What is Scan Conversion?

It is a process of representing graphics objects a collection of pixels. The graphics objects are continuous. The pixels used are discrete. Each pixel can have either on or off state.

The circuitry of the video display device of the computer is capable of converting binary values (0, 1) into a pixel on and pixel off information. 0 is represented by pixel off. 1 is represented using pixel on. Using this ability graphics computer represent picture having discrete dots.

Any model of graphics can be reproduced with a dense matrix of dots or points. Most human beings think graphics objects as points, lines, circles, ellipses. For generating graphical object, many algorithms have been developed.

Advantage of developing algorithms for scan conversion:

  1. Algorithms can generate graphics objects at a faster rate.
  2. Using algorithms memory can be used efficiently.
  3. Algorithms can develop a higher level of graphical objects.

Examples of objects which can be scan converted

  1. Point
  2. Line
  3. Sector
  4. Arc
  5. Ellipse
  6. Rectangle
  7. Polygon
  8. Characters
  9. Filled Regions

The process of converting is also called as rasterization. The algorithms implementation varies from one computer system to another computer system.

Some algorithms are implemented using the software. Some are performed using hardware or firmware. Some are performed using various combinations of hardware, firmware, and software.