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- "Pictures" redirects here. For movies, see Film. For other uses of Image, see Image (disambiguation).
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In common usage, an image (from Latin imago) or picture is an artifact that reproduces the likeness of some subject—usually a physical object or a person.
Images may be two dimensional, such as a photograph, or three dimensional such as in a statue. They are typically produced by optical devices—such as a cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water surfaces.
The word image is also used in the broader sense of any two-dimensional figure or illustration, such as a map, a graph, a pie chart, or an abstract painting. In this wider sense, images can also be produced manually, such as by drawing, painting, carving, by computer graphics technology, or a combination of the two, especially in a pseudo-photograph.
A volatile image are one that exists only for a short period of time. This may be a reflection of an object by a mirror, a projection of the sun on a wall by a pinhole camera, or a scene displayed on a cathode ray tube. A fixed image, also called a hardcopy, is one that has been recorded on a material object, such as paper or textile.
A mental image exists in someone's mind: 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. For example, Sigmund Freud claimed to have dreamt purely in aural-images of dialogues. The development of synthetic acousitic technologies and the creation of sound art have led to a consideration of the possibilities of a sound-image comprosided of irriducible phonic substance beyond linguistic or musicological analysis.
[edit] Specialized meanings
The word also has many special meanings in various disciplines and contexts:
- In geometric optics, a lens can produce a real image or a virtual image.
- In many other scientific and technical contexts, images usually means a two-dimensional signal—a physical phenomenon that can be modeled as a function from a two-dimensional domain (such as the plane or a rectangle) to some set of values, usually real numbers or vectors. This sense covers not only digital images but also analog ones, such as photographs. See image processing.
- In computer graphics and digital image processing, image almost always means digital image or, by extension, any computer description of an image, e.g. a raster map, an image file, or a 2D computer graphics model.
- In computer science, image can mean an exact (bit-by-bit) copy of the contents of some device, such as a hard disk, floppy disk, or CD-ROM. In particular:
- A core image (or core dump, from magnetic core memory, the predominant RAM technology of the 1960s) is a faithful copy of the data stored in the main memory of a computer or process.
- An executable image is a structured file containing machine instructions and data, which can be loaded into a process's virtual memory and executed by the computer's kernel.
- A ROM image is a copy of the contents of an entire ROM chip. Many video games are functionally ROM, so a common usage of ROM images is to store games on other medium for use by console emulators.
- In mathematics, the image of a function consists of its output values.
- In finance, the image is a coefficient (stock image) that bridges a stock's fundamental value and its market price.
- In religion, a cult image is a man-made representation of a deity that is venerated, often associated with idolatry.
- In social psychology, an image is an outward representation, similar to the superego.
- In marketing, brand image is the perception that consumers have for a brand in what values and benefits it offers.
[edit] See also