Editing 2D computer graphics (section)

{{Short description|Computer-based generation of digital images}}
{{Multiple issues|
{{Refimprove|date=December 2009}}
{{Original research|date=July 2019}}
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'''2D computer graphics''' is the [[computer-generated imagery|computer-based]] generation of [[digital image]]s&mdash;mostly from two-dimensional models (such as [[2D geometric model]]s, text, and digital images) and by techniques specific to them. It may refer to the branch of [[computer science]] that comprises such techniques or to the models themselves.

[[File:Blit dot.gif|thumb|[[Raster graphics|Raster graphic]] [[Sprite (computer graphics)|sprite]]s (left) and masks]]
2D computer graphics are mainly used in applications that were originally developed upon traditional [[printing]] and [[drawing]] technologies, such as [[typography]], [[cartography]], [[technical drawing]], [[advertising]], etc.  In those applications, the two-dimensional [[image]] is not just a representation of a real-world object, but an independent artifact with added semantic value; two-dimensional models are therefore preferred, because they give more direct control of the image than [[3D computer graphics]] (whose approach is more akin to [[photography]] than to typography).

In many domains, such as [[desktop publishing]], [[engineering]], and [[business]], a description of a document based on 2D computer graphics techniques can be much smaller than the corresponding digital image&mdash;often by a factor of 1/1000 or more.  This representation is also more flexible since it can be [[rendering (computer graphics)|rendered]] at different [[Image resolution|resolution]]s to suit different [[output device]]s.  For these reasons, documents and illustrations are often stored or transmitted as [[graphics file format|2D graphic files]].

2D computer graphics started in the 1950s, based on [[vector graphics|vector graphics devices]]. These were largely supplanted by [[raster graphics|raster-based devices]] in the following decades. The [[PostScript]] language and the [[X Window System]] protocol were landmark developments in the field.

2D graphics models may combine [[2D geometric model|geometric model]]s (also called [[vector graphics]]), digital images (also called [[raster graphics]]), text to be [[typesetting|typeset]] (defined by content, [[Typeface|font]] style and size, color, position, and orientation), mathematical [[function (mathematics)|function]]s and [[equation]]s, and more.  These components can be modified and manipulated by two-dimensional [[Transformation (geometry)|geometric transformation]]s such as [[translation (geometry)|translation]], [[rotation]], and [[Scaling (geometry)|scaling]].
In [[object-oriented graphics]], the image is described indirectly by an [[object (computer science)|object]] endowed with a self-[[rendering (computer graphics)|rendering]] [[method (computer science)|method]]&mdash;a procedure that assigns colors to the image [[pixel]]s by an arbitrary algorithm.  Complex models can be built by combining simpler objects, in the [[paradigms]] of [[object-oriented programming]].