Editing Line drawing algorithm (section)

{{Short description|Methods of approximating line segments for pixel displays}}
{{Expand German|Rasterung von Linien|fa=yes|topic=sci|date=December 2009}}
[[File:Line scan-conversion.svg|thumb|upright=1.0|Two rasterized lines. The colored pixels are shown as circles. Above: monochrome screening; below: Gupta-Sproull anti-aliasing; the ideal line is considered here as a surface.]]

In [[computer graphics]], a '''line drawing algorithm''' is an [[algorithm]] for approximating a [[line segment]] on discrete [[Graphics|graphical]] media, such as [[pixel]]-based [[computer display|displays]] and [[computer printer|printers]]. On such media, line drawing requires an [[Approximation algorithm|approximation]] (in nontrivial cases). Basic algorithms [[Rasterisation|rasterize]] lines in one color. A better representation with multiple [[Gradation (art)|color gradations]] requires an advanced process, [[spatial anti-aliasing]].

On continuous media, by contrast, no algorithm is necessary to draw a line. For example, [[cathode-ray oscilloscope]]s use analog phenomena to draw lines and curves.