2D computer graphics is the
computerA computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
-based generation of
digital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
s—mostly from two-dimensional models (such as
2D geometric modelA 2D geometric model is a geometric model of an object as two-dimensional figure, usually on the Euclidean or Cartesian plane.Even though all material objects are three-dimensional, a 2D geometric model is often adequate for certain flat objects, such as paper cut-outs and machine parts made of...
s, text, and digital images) and by techniques specific to them. The word may stand for the branch of
computer scienceComputer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
that comprises such techniques, or for the models themselves.
2D computer graphics are mainly used in applications that were originally developed upon traditional
printingPrinting is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
and
drawingDrawing is a form of visual art that makes use of any number of drawing instruments to mark a two-dimensional medium. Common instruments include graphite pencils, pen and ink, inked brushes, wax color pencils, crayons, charcoal, chalk, pastels, markers, styluses, and various metals .An artist who...
technologies, such as
typographyTypography is the art and technique of arranging type in order to make language visible. The arrangement of type involves the selection of typefaces, point size, line length, leading , adjusting the spaces between groups of letters and adjusting the space between pairs of letters...
,
cartographyCartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...
,
technical drawingTechnical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....
,
advertisingAdvertising is a form of communication used to persuade an audience to take some action with respect to products, ideas, or services. Most commonly, the desired result is to drive consumer behavior with respect to a commercial offering, although political and ideological advertising is also common...
, etc. In those applications, the two-dimensional
imageAn image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
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 graphics3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
(whose approach is more akin to
photographyPhotography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
than to
typographyTypography is the art and technique of arranging type in order to make language visible. The arrangement of type involves the selection of typefaces, point size, line length, leading , adjusting the spaces between groups of letters and adjusting the space between pairs of letters...
).
In many domains, such as
desktop publishingDesktop publishing is the creation of documents using page layout software on a personal computer.The term has been used for publishing at all levels, from small-circulation documents such as local newsletters to books, magazines and newspapers...
,
engineeringEngineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
, and
businessA business is an organization engaged in the trade of goods, services, or both to consumers. Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit...
, a description of a document based on 2D computer graphics techniques can be much smaller than the corresponding
digital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
—often by a factor of 1/1000 or more. This representation is also more flexible since it can be
renderedRendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...
at different
resolutionImage resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....
s to suit different
output deviceAn output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system to the outside world....
s. For these reasons, documents and illustrations are often stored or transmitted as 2D graphic files.
2D computer graphics started in the 1950s, based on
vector graphics devicesVector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
. These were largely supplanted by
raster-based devicesIn computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
in the following decades. The
PostScriptPostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...
language and the
X Window SystemThe X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
protocol were landmark developments in the field.
2D graphics techniques
2D graphics models may combine
geometric modelA 2D geometric model is a geometric model of an object as two-dimensional figure, usually on the Euclidean or Cartesian plane.Even though all material objects are three-dimensional, a 2D geometric model is often adequate for certain flat objects, such as paper cut-outs and machine parts made of...
s (also called
vector graphicsVector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
),
digital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
s (also called
raster graphicsIn computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
), text to be
typesetTypesetting is the composition of text by means of types.Typesetting requires the prior process of designing a font and storing it in some manner...
(defined by content,
fontIn typography, a typeface is the artistic representation or interpretation of characters; it is the way the type looks. Each type is designed and there are thousands of different typefaces in existence, with new ones being developed constantly....
style and size, color, position, and orientation), mathematical
functionIn mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...
s and
equationAn equation is a mathematical statement that asserts the equality of two expressions. In modern notation, this is written by placing the expressions on either side of an equals sign , for examplex + 3 = 5\,asserts that x+3 is equal to 5...
s, and more. These components can be modified and manipulated by two-dimensional geometric transformations such as
translationIn Euclidean geometry, a translation moves every point a constant distance in a specified direction. A translation can be described as a rigid motion, other rigid motions include rotations and reflections. A translation can also be interpreted as the addition of a constant vector to every point, or...
,
rotationA rotation is a circular movement of an object around a center of rotation. A three-dimensional object rotates always around an imaginary line called a rotation axis. If the axis is within the body, and passes through its center of mass the body is said to rotate upon itself, or spin. A rotation...
,
scalingIn Euclidean geometry, uniform scaling is a linear transformation that enlarges or shrinks objects by a scale factor that is the same in all directions. The result of uniform scaling is similar to the original...
.
In object-oriented graphics, the image is described indirectly by an
objectIn computer science, an object is any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure...
endowed with a self-
renderingRendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...
methodIn object-oriented programming, a method is a subroutine associated with a class. Methods define the behavior to be exhibited by instances of the associated class at program run time...
—a procedure which assigns colors to the image
pixelIn digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s by an arbitrary algorithm. Complex models can be built by combining simpler objects, in the paradigms of
object-oriented programmingObject-oriented programming is a programming paradigm using "objects" – data structures consisting of data fields and methods together with their interactions – to design applications and computer programs. Programming techniques may include features such as data abstraction,...
.
Direct painting
A convenient way to create a complex image is to start with a blank "canvas"
raster mapIn computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
(an array of
pixelIn digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s, also known as a
bitmapIn computer graphics, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to...
) filled with some uniform background color and then "draw", "paint" or "paste" simple patches of color onto it, in an appropriate order. In particular, the canvas may be the frame buffer for a
computer displayA monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
.
Some programs will set the pixel colors directly, but most will rely on some 2D
graphics libraryA graphics library is a program library designed to aid in rendering computer graphics to a monitor. This typically involves providing optimized versions of functions that handle common rendering tasks. This can be done purely in software and running on the CPU, common in embedded systems, or being...
and/or the machine's graphics card, which usually implement the following operations:
- paste a given image
A digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
at a specified offset onto the canvas;
- write a string of characters with a specified font, at a given position and angle;
- paint a simple geometric shape, such as a triangle
A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ....
defined by three corners, or a circleA circle is a simple shape of Euclidean geometry consisting of those points in a plane that are a given distance from a given point, the centre. The distance between any of the points and the centre is called the radius....
with given center and radius;
- draw a line segment
In geometry, a line segment is a part of a line that is bounded by two end points, and contains every point on the line between its end points. Examples of line segments include the sides of a triangle or square. More generally, when the end points are both vertices of a polygon, the line segment...
, arcIn geometry, an arc is a closed segment of a differentiable curve in the two-dimensional plane; for example, a circular arc is a segment of the circumference of a circle...
, or simple curve with a virtual pen of given width.
Extended color models
Text, shapes and lines are rendered with a client-specified color. Many libraries and cards provide
color gradientIn computer graphics, a color gradient specifies a range of position-dependent colors, usually used to fill a region. For example, many window managers allow the screen background to be specified as a gradient...
s, which are handy for the generation of smoothly-varying backgrounds, shadow effects, etc. (See also
Gouraud shadingGouraud shading, named after Henri Gouraud, is an interpolation method used in computer graphics to produce continuous shading of surfaces represented by polygon meshes...
). The pixel colors can also be taken from a texture, e.g. a
digital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
(thus emulating rub-on
screentoneScreentone is a technique for applying textures and shades to drawings, used as an alternative to hatching. In the conventional process, patterns are transferred to paper from preprinted sheets, but the technique is also simulated in computer graphics...
s and the fabled "checker paint" which used to be available only in
cartoonA cartoon is a form of two-dimensional illustrated visual art. While the specific definition has changed over time, modern usage refers to a typically non-realistic or semi-realistic drawing or painting intended for satire, caricature, or humor, or to the artistic style of such works...
s).
Painting a
pixelIn digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
with a given color usually replaces its previous color. However, many systems support painting with
transparentTransparency is possible in a number of graphics file formats. The term transparency is used in various ways by different people, but at its simplest there is "full transparency" i.e. something that is completely invisible. Of course, only part of a graphic should be fully transparent, or there...
and translucent colors, which only modify the previous pixel values.
The two colors may also be combined in fancier ways, e.g. by computing their
bitwiseA bitwise operation operates on one or more bit patterns or binary numerals at the level of their individual bits. This is used directly at the digital hardware level as well as in microcode, machine code and certain kinds of high level languages...
exclusive or. This technique is known as inverting color or color inversion, and is often used in
graphical user interfaceIn computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
s for highlighting, rubber-band drawing, and other volatile painting—since re-painting the same shapes with the same color will restore the original pixel values.
Layers
The models used in 2D computer graphics usually do not provide for three-dimensional shapes, or three-dimensional optical phenomena such as lighting,
shadowA shadow is an area where direct light from a light source cannot reach due to obstruction by an object. It occupies all of the space behind an opaque object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or reverse projection of the object blocking the...
s,
reflectionReflection is the change in direction of a wavefront at an interface between two differentmedia so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves...
,
refractionRefraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
, etc. However, they usually can model multiple
layers (conceptually of ink, paper, or film; opaque, translucent, or
transparentTransparency is possible in a number of graphics file formats. The term transparency is used in various ways by different people, but at its simplest there is "full transparency" i.e. something that is completely invisible. Of course, only part of a graphic should be fully transparent, or there...
—stacked in a specific order. The ordering is usually defined by a single number (the layer's
depth, or distance from the viewer).
Layered models are sometimes called
2½-D computer graphics. They make it possible to mimic traditional drafting and printing techniques based on film and paper, such as cutting and pasting; and allow the user to edit any layer without affecting the others. For these reasons, they are used in most graphics editors. Layered models also allow better
anti-aliasingIn digital signal processing, spatial anti-aliasing is the technique of minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution...
of complex drawings and provide a sound model for certain techniques such as mitered joints and the
even-odd ruleThe even–odd rule is an algorithm implemented in vector-based graphic software, like the PostScript language, which determines how a graphical shape with more than one closed outline will be filled...
.
Layered models are also used to allow the user to suppress unwanted information when viewing or printing a document, e.g. roads and/or railways from a
mapA map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....
, certain process layers from an
integrated circuitAn integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
diagram, or hand annotations from a business letter.
In a layer-based model, the target image is produced by "painting" or "pasting" each layer, in order of decreasing depth, on the virtual canvas. Conceptually, each layer is first
renderedRendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...
on its own, yielding a
digital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
with the desired
resolutionImage resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....
which is then painted over the canvas, pixel by pixel. Fully transparent parts of a layer need not be rendered, of course. The rendering and painting may be done in parallel, i.e. each layer pixel may be painted on the canvas as soon as it is produced by the rendering procedure.
Layers that consist of complex geometric objects (such as
textIn formal languages, which are used in mathematical logic and theoretical computer science, a string is a finite sequence of symbols that are chosen from a set or alphabet....
or polylines) may be broken down into simpler elements (
characterIn computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language....
s or
line segmentIn geometry, a line segment is a part of a line that is bounded by two end points, and contains every point on the line between its end points. Examples of line segments include the sides of a triangle or square. More generally, when the end points are both vertices of a polygon, the line segment...
s, respectively), which are then painted as separate layers, in some order. However, this solution may create undesirable
aliasingIn signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable when sampled...
artifacts wherever two elements overlap the same pixel.
See also Portable Document Format#Layers.
2D graphics hardware
Modern computer graphics card displays almost overwhelmingly use raster techniques, dividing the screen into a rectangular grid of
pixelIn digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s, due to the relatively low cost of raster-based video hardware as compared with vector graphic hardware. Most graphic hardware has internal support for blitting operations and
spriteIn computer graphics, a sprite is a two-dimensional image or animation that is integrated into a larger scene...
drawing. A co-processor dedicated to blitting is known as a
BlitterIn a computer system, a blitter is a circuit, sometimes as a coprocessor or a logic block on a microprocessor, that is dedicated to the rapid movement and modification of data within that computer's memory...
chip.
Classic 2D graphics chips of the late 1970s and early 1980s, used in the
8-bitThe first widely adopted 8-bit microprocessor was the Intel 8080, being used in many hobbyist computers of the late 1970s and early 1980s, often running the CP/M operating system. The Zilog Z80 and the Motorola 6800 were also used in similar computers...
video game consoleA video game console is an interactive entertainment computer or customized computer system that produces a video display signal which can be used with a display device to display a video game...
s and
home computerHome computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...
s, include:
- Atari
Atari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...
's ANTICAlphanumeric Television Interface Controller is an early video system chip used in the Atari 8-bit family of microcomputers as well as the Atari 5200 in the 1980s. The chip was patented by Atari, Inc. in 1981...
(actually a 2D GPUA graphics processing unit or GPU is a specialized circuit designed to rapidly manipulate and alter memory in such a way so as to accelerate the building of images in a frame buffer intended for output to a display...
), TIAThe Television Interface Adaptor is the custom computer chip that is the heart of the Atari 2600 game console, generating the screen display, sound effects, and reading input controllers. Its design was widely affected by an attempt to reduce the amount of RAM needed to operate the display...
, CTIA, and GTIAColor Television Interface Adaptor and its successor Graphic Television Interface Adaptor are custom chips used in the Atari 8-bit family of computers and in the Atari 5200 console. In these systems, a CTIA or GTIA chip works together with ANTIC to produce video display...
- Commodore
Commodore is the commonly used name for Commodore Business Machines , the U.S.-based home computer manufacturer and electronics manufacturer headquartered in West Chester, Pennsylvania, which also housed Commodore's corporate parent company, Commodore International Limited...
/MOS TechnologyMOS Technology, Inc., also known as CSG , was a semiconductor design and fabrication company based in Norristown, Pennsylvania, in the United States. It is most famous for its 6502 microprocessor, and various designs for Commodore International's range of home computers.-History:MOS Technology, Inc...
's VICThe VIC , specifically known as the MOS Technology 6560 / 6561 , is the integrated circuit chip responsible for generating video graphics and sound in the Commodore VIC-20 home computer...
and VIC-IIThe VIC-II , specifically known as the MOS Technology 6567/8562/8564 , 6569/8565/8566 , is the microchip tasked with generating Y/C/composite video graphics and DRAM refresh signals in the Commodore 64 and C128 home computers.Succeeding MOS's original VIC , the VIC-II was one of the two chips...
2D graphics software
Many
graphical user interfaceIn computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
s (GUIs), including
Mac OSMac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...
,
Microsoft WindowsMicrosoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
, or the
X Window SystemThe X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
, are primarily based on 2D graphical concepts. Such software provides a visual environment for interacting with the computer, and commonly includes some form of
window managerA window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment...
to aid the user in conceptually distinguishing between different applications.
The user interface within individual software applications is typically 2D in nature as well, due in part to the fact that most common
input deviceIn computing, an input device is any peripheral used to provide data and control signals to an information processing system such as a computer or other information appliance...
s, such as the mouse, are constrained to two dimensions of movement.
2D graphics are very important in the control peripherals such as printers, plotters, sheet cutting machines, etc. They were also used in most early video and computer games; and are still used for card and board games such as
solitaireSolitaire is any tabletop game which one can play by oneself or with other people. The solitaire card game Klondike is often known as simply Solitaire....
,
chessChess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...
, mahjongg, etc.
2D graphics editors or
drawing programs are application-level software for the creation of images, diagrams and illustrations by direct manipulation (through the mouse,
graphics tabletA graphics tablet is a computer input device that enables a user to hand-draw images and graphics, similar to the way a person draws images with a pencil and paper. These tablets may also be used to capture data or handwritten signatures...
, or similar device) of 2D computer graphics primitives. These editors generally provide geometric primitives as well as
digital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
s; and some even support procedural models. The illustration is usually represented internally as a layered model, often with a hierarchical structure to make editing more convenient. These editors generally output graphics files where the layers and primitives are separately preserved in their original form.
MacDrawMacDraw was a vector based drawing application released along with the first Apple Macintosh systems in 1984. MacDraw was one of the first WYSIWYG drawing programs that could be used in collaboration with MacWrite. MacDraw was useful for drawing technical diagrams and floorplans...
, introduced in 1984 with the Macintosh line of computers, was an early example of this class; recent examples are the commercial products
Adobe IllustratorAdobe Illustrator is a vector graphics editor developed and marketed by Adobe Systems. Illustrator is similar in scope, intended market, and functionality to its competitors, CorelDraw, Xara Designer Pro and Macromedia FreeHand....
and
CorelDRAWCorelDRAW is a vector graphics editor developed and marketed by Corel Corporation of Ottawa, Canada. It is also the name of Corel's Graphics Suite...
, and the free editors such as
xfigXfig is a Free and open source vector graphics editor which runs under the X Window System on most UNIX-compatible platforms.In Xfig, figures may be drawn using objects such as circles, boxes, lines, spline curves, text, etc. It is also possible to import images in formats such as GIF, JPEG, EPS,...
or
InkscapeInkscape is a free software vector graphics editor, licensed under the GNU General Public License. Its goal is to implement full support for the Scalable Vector Graphics 1.1 standard....
. There are also many 2D graphics editors specialized for certain types of drawings such as electrical, electronic and VLSI diagrams, topographic maps, computer fonts, etc.
Image editorsDigital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing...
are specialized for the manipulation of
digital imageA digital image is a numeric representation of a two-dimensional image. Depending on whether or not the image resolution is fixed, it may be of vector or raster type...
s, mainly by means of free-hand drawing/painting and
signal processingSignal processing is an area of systems engineering, electrical engineering and applied mathematics that deals with operations on or analysis of signals, in either discrete or continuous time...
operations. They typically use a direct-painting paradigm, where the user controls virtual pens, brushes, and other free-hand artistic instruments to apply paint to a virtual canvas. Some image editors support a multiple-layer model; however, in order to support signal-processing operations like blurring each layer is normally represented as a digital image. Therefore, any geometric primitives that are provided by the editor are immediately converted to pixels and painted onto the canvas. The name
raster graphics editor is sometimes used to contrast this approach to that of general editors which also handle
vector graphics. One of the first popular image editors was
AppleApple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...
's
MacPaintMacPaint was a bitmap-based graphics painting software program developed by Apple Computer and released with the original Macintosh personal computer on January 22, 1984. It was sold separately for US$195 with its word processor counterpart, MacWrite. MacPaint was notable because it could generate...
, companion to
MacDrawMacDraw was a vector based drawing application released along with the first Apple Macintosh systems in 1984. MacDraw was one of the first WYSIWYG drawing programs that could be used in collaboration with MacWrite. MacDraw was useful for drawing technical diagrams and floorplans...
. Modern examples are the free
GIMPGIMP is a free software raster graphics editor. It is primarily employed as an image retouching and editing tool and is freely available in versions tailored for most popular operating systems including Microsoft Windows, Apple Mac OS X, and Linux.In addition to detailed image retouching and...
editor, and the commercial products Photoshop and Paint Shop Pro. This class too includes many specialized editors — for medicine, remote sensing,
digital photographyDigital photography is a form of photography that uses an array of light sensitive sensors to capture the image focused by the lens, as opposed to an exposure on light sensitive film...
, etc.
Developmental animation
With the resurgence of 2D animation and its booming popularity, free and proprietary software packages have become widely available for amateurs and professional animators. However, the principal issue with 2D animation is labor requirements. With advanced software like
RETASRETAS is a 2D animation software bundle developed and sold by Celsys that's available for Microsoft Windows and Mac OS X...
and
Adobe After EffectsAdobe After Effects is a digital motion graphics and compositing software published by Adobe Systems, used in the post-production process of filmmaking and television production. Its main uses are the origination of 2D and 2.5D animation, visual effects compositing and finishing...
, coloring and compositing can be easily done with significantly less time.
Additional software is being developed to aid and speed up the process of digital 2D animation, specifically in the area of automatic coloring and
in-betweeningInbetweening or tweening is the process of generating intermediate frames between two images to give the appearance that the first image evolves smoothly into the second image. Inbetweens are the drawings between the key frames which help to create the illusion of motion...
.
See also
- 2.5D
2.5D , 3/4 perspective and pseudo-3D are terms used to describe either:* 2D graphical projections and techniques which cause a series of images or scenes to fake or appear to be three-dimensional when in fact they are not, or* gameplay in an otherwise three-dimensional video game that is...
- 3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
- Bit blit
Bit BLIT is a computer graphics operation in which several bitmaps are combined into one using a raster operator....
- Computer graphics
Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....
- Graphic art software
- Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...
- Image scaling
In computer graphics, image scaling is the process of resizing a digital image. Scaling is a non-trivial process that involves a trade-off between efficiency, smoothness and sharpness. As the size of an image is increased, so the pixels which comprise the image become increasingly visible, making...
- List of home computers by video hardware
- Turtle graphics
Turtle graphics is a term in computer graphics for a method of programming vector graphics using a relative cursor upon a Cartesian plane...
- Transparency in graphics
Transparency is possible in a number of graphics file formats. The term transparency is used in various ways by different people, but at its simplest there is "full transparency" i.e. something that is completely invisible. Of course, only part of a graphic should be fully transparent, or there...
- Palette (computing)
In computer graphics, a palette is either a given, finite set of colors for the management of digital images , or a small on-screen graphical element for choosing from a limited set of choices, not necessarily colors .Depending on the context In computer graphics, a palette is either a given,...
- Pixel art
Pixel art is a form of digital art, created through the use of raster graphics software, where images are edited on the pixel level. Graphics in most old computer and video games, graphing calculator games, and many mobile phone games are mostly pixel art.- History :The term pixel art was first...