An image is a visual representation of something. It can be

two-dimensional In mathematics, a plane is a Euclidean (flat), two-dimensional surface that extends indefinitely. A plane is the two-dimensional analogue of a point (zero dimensions), a line (one dimension) and three-dimensional space. Planes can arise as s ...

three-dimensional Three-dimensional space (also: 3D space, 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called ''parameters'') are required to determine the position of an element (i.e., point). This is the informal ...

, or somehow otherwise feed into the

visual system The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight (the a ...

to convey information. An image can be an artifact, such as a photograph or other two-dimensional picture, that resembles a subject. In the context of signal processing, an image is a distributed amplitude of color(s). In optics, the term “image” may refer specifically to a 2D image. An image does not have to use the entire

to be a visual representation. A popular example of this is of a

greyscale In digital photography, computer-generated imagery, and colorimetry, a grayscale image is one in which the value of each pixel is a single sample representing only an ''amount'' of light; that is, it carries only intensity information. Graysca ...

image, which uses the visual system's sensitivity to brightness across all wavelengths, without taking into account different colors. A black and white visual representation of something is still an image, even though it does not make full use of the visual system's capabilities. Images are typically still, but in some cases can be moving or animated.

Characteristics

Images may be two or three-

dimensional In physics and mathematics, the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it. Thus, a line has a dimension of one (1D) because only one coordi ...

, such as a

photograph A photograph (also known as a photo, image, or picture) is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now create ...

or screen display, or three-dimensional, such as a

statue A statue is a free-standing sculpture in which the realistic, full-length figures of persons or animals are carved or cast in a durable material such as wood, metal or stone. Typical statues are life-sized or close to life-size; a sculpture t ...

hologram Holography is a technique that enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating real three-dimensional images, but it also has a wide range of other Holography#Applications, applic ...

. They may be captured by

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviole ...

devices – such as

camera A camera is an Optics, optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), ...

mirror A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...

lenses A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...

s, etc. and natural objects and phenomena, such as the

human eye The human eye is a sensory organ, part of the sensory nervous system, that reacts to visible light and allows humans to use visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm. ...

or water. The word 'image' is also used in the broader sense of any two-dimensional figure such as a

map A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes. Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although ...

, a

graph Graph may refer to: Mathematics *Graph (discrete mathematics), a structure made of vertices and edges **Graph theory, the study of such graphs and their properties *Graph (topology), a topological space resembling a graph in the sense of discre ...

, a

pie chart A pie chart (or a circle chart) is a circular Statistical graphics, statistical graphic, which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and are ...

, a

painting Painting is the practice of applying paint, pigment, color or other medium to a solid surface (called the "matrix" or "support"). The medium is commonly applied to the base with a brush, but other implements, such as knives, sponges, and ...

or a

banner A banner can be a flag or another piece of cloth bearing a symbol, logo, slogan or another message. A flag whose design is the same as the shield in a coat of arms (but usually in a square or rectangular shape) is called a banner of arms. Also, ...

. In this wider sense, images can also be ''rendered'' manually, such as by

drawing Drawing is a form of visual art in which an artist uses instruments to mark paper or other two-dimensional surface. Drawing instruments include graphite pencils, pen and ink, various kinds of paints, inked brushes, colored pencils, crayons, ...

, the art of painting, carving, rendered automatically by printing or computer graphics technology, or developed by a combination of methods. A volatile image is one that exists only for a short period of time. This may be a reflection of an object by a mirror, a projection of a camera obscura, or a scene displayed on a

cathode ray tube A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms ( oscilloscope), pictu ...

. A fixed image, also called a hard copy, is one that has been recorded on a material object, such as paper or textile by photography or any other digital process. A mental image exists in an individual's mind, as something one remembers or imagines. The subject of an image need not be real; it may be an abstract concept, such as a graph, function, or imaginary entity. Different scholars of psychoanalysis as well as the social sciences such as Slavoj Žižek and Jan Berger have pointed out the possibility of manipulating mental images for ideological purposes.

In culture

Images perpetuated in public education, media as well as popular culture have a profound impact on the formation of such mental images:

"What makes them so powerful is that they circumvent the faculties of the conscious mind but, instead, directly target the subconscious and affective, thus evading direct inquiry through contemplative reasoning. By doing so such axiomatic images tell us what we shall desire (liberalism, in a snapshot: the crunchy honey-flavored cereals and the freshly-pressed orange juice in the back of a suburban one-family home) and from what we shall obstain (communism, in a snapshot: lifeless crowds of men and machinery marching towards certain perdition accompanied by the tunes of Soviet Russian songs). What makes those images so powerful is that it is only of relative minor relevance for the stabilization of such images whether they actually capture and correspond with the multiple layers of reality, or not." - David Leupold, sociologist.

The development of synthetic acoustic technologies and the creation of sound art have led to a consideration of the possibilities of a sound-image made up of irreducible phonic substance beyond linguistic or musicological analysis.

Still or moving

A ' is a single static image. This phrase is used in photography, visual media and the

computer industry A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These progra ...

to emphasize that one is not talking about movies, or in very precise or pedantic technical writing such as a standard. A ' is typically a movie (

film A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...

) or video, including

digital video Digital video is an electronic representation of moving visual images (video) in the form of encoded digital data. This is in contrast to analog video, which represents moving visual images in the form of analog signals. Digital video comprises ...

. It could also be an animated display such as a zoetrope. A still frame is a still image derived from one frame of a moving one. In contrast, a

film still A film still (sometimes called a publicity still or a production still) is a photograph, taken on or off the set of a movie or television program during production. These photographs are also taken in formal studio settings and venues of opportun ...

is a photograph taken on the set of a movie or television program during production, used for promotional purposes.

Two-dimensional (2D)

A two dimensional (2D) image is a visual representation of something that is represented using only two spatial dimensions. Many 2D images are in the shape of rectangles. A common process by which 2D images have historically been displayed is called rasterization. As of 2021, 2D images are the most common types of image.

Three-dimensional (3D)

Three-dimensional (3D) images are less common than two-dimensional images. Three dimensional images feed into the visual system’s perception of depth to more accurately portray visual information. Common physical forms of 3D images include

Literature

In literature, imagery is a "mental picture" which appeals to the senses. It can both be figurative and literal.

References

{{Authority control Photography Digital photography Computer graphics Graphic design Vision