This is an old revision of this page, as edited by 206.15.235.3 (talk) at 18:10, 16 November 2006. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 18:10, 16 November 2006 by 206.15.235.3 (talk)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)- "Pictures" redirects here. For movies, see Film. For other uses of Image, see Image (disambiguation).
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.people belive in this 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.
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.
See also
- Art
- Optics
- Imaging
- Photography
- Digital imaging
- Virtual artifact
- Image processing
- Computer image analysis