tasvir-e târ, ~ nâtig
Fr.: image estompée, ~ floue
Fr.: image intégrée
An image made up of several individual images of relatively short exposure times which are added together in order to produce a final image of higher quality.
Fr.: image profonde
An image obtained using a deep exposure to reveal the weak features of the object.
differential image motion monitor (DIMM)
pahregar-e jonbeš-e degarsâneyi-ye tasvir
Fr.: moniteur de mouvements d'images différentiels, moniteur seeing
A device that is commonly used to measure the → seeing at optical astronomical sites. The DIMM delivers an estimate of the → Fried parameter based on measuring the variance of the differential image motion in two small apertures, usually cut out in a single larger telescope pupil by a mask. The DIMM concept was introduced by Stock & Keller (1960, in Stars and Stellar Systems, Vol. 1, ed. G. P. Kuiper & B. M. Middlehurst, p. 138), whereas its modern implementation was first described by Sarazin & Roddier (1990, A&A 227, 294).
Fr.: image floue, ~ estompée
Same as → blurred image.
In an optical system, the point to which light rays are converged (real image) or
from which they appear to diverge (virtual image) after reflection or refraction.
From O.Fr. image, from L. imaginem (nom. imago) "copy, picture, likeness " from stem of imitari "to copy, imitate," from im-, stem of imitare "to copy, imitate" + -ago noun suffix.
Tasvir, loan from Ar.
Fr.: addition d'images
The process of adding several usually low-exposure images to create an image having a significantly higher signal/noise ratio.
Fr.: correction de l'image brouillée
A technique using a mathematical model of the blurring process to recover the original, sharp image. See also → blurred image.
Fr.: formation de l'image
The meeting of light rays emanating from an object after crossing an optical system.
Fr.: intensificateur d'image
Device that produces an observable image that is brighter at output than the image at input.
Fr.: plan d'image
The plane in which is formed an image produced by an → optical system.
Fr.: point image
One of the points constituting an extended image formed in an → optical system.
Fr.: traitement d'image
The use of techniques to produce, extract, identify, and display images for evaluation, interpretation, and further interaction with the data.
Fr.: qualité d'image
1) The degree of visibility of relevant → information
in an image.
Fr.: résolution d'image
The separation between two detached but adjacent points in an image.
bâzsâzi-ye tasvir (#)
Fr.: restauration d'image
The process by virtue of which the original image can be created by removing the blurring and the noise that occur during image formation.
Fr.: échelle de l'image
The quantity that relates the length on the image to the angular or physical separations on the sky.
Fr.: espace image
Fr.: tube imageur
A device for amplifying faint images by electronic means. Electrons, released when the incident radiation forms a pattern on a photocathode, are accelerated by a magnetic field so that they form a second, brighter image when they strike a phosphor screen.
Fr.: image réelle