image (redirected from Pictures are closer)

image, in optics, likeness or counterpart of an object produced when rays of light coming from that object are reflected from a mirror or are refracted by a lens. An image of an object is also formed when this light passes through a very small opening like that of a pinhole camera (which has no lens). Images are classed as real or virtual. A real image occurs when the rays of light from the object actually converge to form an image and can be seen on a screen placed at the point of convergence. For example, the image produced by the refraction of light rays by a convex lens (when the distance between the object and the lens is greater than the focal length of the lens) is real, and it appears on the side of the lens opposite the one on which the object is present. On the other hand, a virtual image occurs when the prolongations of the light rays converge to form an image, but the light rays themselves do not reach the point of convergence. Thus a virtual image cannot be seen on a screen. The image in a plane mirror is virtual. It appears to be behind the mirror, at a distance equal to that of the object in front, although the rays of light from the object do not penetrate the mirror but are reflected from it. Images of the same size as the object are sometimes produced, as in the case of the plane mirror, but in other cases they are larger, and in still others, smaller. They are sometimes erect and in other cases are inverted. The size of the image and whether it is erect or inverted, real or virtual, depend on the distance of the object from the lens or mirror relative to the focal length and on the type of lens or mirror (plane, convex, or concave) employed.

---

image

(1) A picture. A graphic. See graphics.

(2) To picture. To display.

(3) See system image.

---

image

1. an optically formed reproduction of an object, such as one formed by a lens or mirror

2. the pattern of light that is focused on to the retina of the eye

3. Psychol the mental experience of something that is not immediately present to the senses, often involving memory

4. a mental picture or association of ideas evoked in a literary work, esp in poetry

5. a figure of speech, such as a simile or metaphor

6. Maths

a. (of a point) the value of a function, f(x), corresponding to the point x

b. the range of a function

---

image [′im·ij]

(acoustics)

acoustic image

(communications)

One of two groups of side bands generated in the process of modulation; the unused group is referred to as the unwanted image.

The scene reproduced by a television or facsimile receiver.

(computer science)

A copy of the information contained in one medium recorded on a different data medium.

(electricity)

electric image

(electromagnetism)

The input reflection coefficient corresponding to the reflection coefficient of a specified load when the load is placed on one side of a waveguide junction and a slotted line is placed on the other.

(mathematics)

For a pointxin the domain of a function ƒ, the point ƒ(x).

For a subsetAof the domain of a function ƒ, the set of all points that are equal to ƒ(x) for some pointxinA.

(optics)

An optical counterpart of a self-luminous or illuminated object formed by the light rays that traverse an optical system; each point of the object has a corresponding point in the image from which rays diverge or appear to diverge.

(physics)

Any reproduction of an object produced by means of focusing light, sound, electron radiation, or other emanations coming from the object or reflected by the object.

(psychology)

A representation of a sensory experience, occurring in the brain.

---

image - 1. Data representing a two-dimensional scene. A digital image is composed of pixels arranged in a rectangular array with a certain height and width. Each pixel may consist of one or more bits of information, representing the brightness of the image at that point and possibly including colour information encoded as RGB triples. Images are usually taken from the real world via a digital camera, frame grabber, or scanner; or they may be generated by computer, e.g. by ray tracing software. See also image formats, image processing.