Image Definition


Also found in: Acronyms.

Definition, Image

 

the degree of distinctness in the border between two parts of a photographic image that have received different exposures. In general, the image boundary of an object having a brightness different from that of the surrounding background is always blurred. Depending on exposure conditions, the transition zone from high optical densities to low densities—the boundary region—is between 10 and 50 microns wide for modern photographic materials. A subjective impression of image definition depends on the rate at which the density in this zone changes and on the absolute difference between the densities at the zone’s edges.

Various methods of measuring definition have been proposed that use the maximum or root-mean-square gradient of the change in the optical density in the boundary region. The highest gradient—the best image definition—is achieved only at a certain optimum exposure. Unlike resolution, image definition characterizes the quality of reproduction for relatively coarse details of a photographic image. When the distance to an object is fixed, it is usually necessary to focus the lens in two different ways to obtain pictures with the best definition and resolution.

M. IA. SHUL’MAN

Mentioned in ?
References in periodicals archive ?
Despite the move to full-frame (35mm) format In recent digital SLR cameras, many macro specialists prefer to use a cropped sensor (APS-C) camera because it extends the focal length of any full-frame lens by a factor of approximately 1.5x and utilises only the central area of the lens for optimum image definition. Converters--1.4x, 1.7x and 2.0x--also give a magnification boost and excellent quality when the lens is stopped down, as In most close-up work.
Ricoh's new toner technology, which has smaller, more uniform particles, produces sharp image definition and smooth transitions in gradients.
The three firms are aiming to jointly develop technology by 2011 to reduce power consumption by LCD TVs which is growing along with the increasing size of displays and higher image definition, according to the sources.
Personal videos make a candidate seem like a human being, a point the communications team can work into the narrative before the freak show moment hardens into a image definition.
According to BASF, the nyloflex N 36 resists swelling in aqueous inks and preserves image definition and ink coverage throughout "extremely high print runs." Platemaking includes a closed circuit for the washout agent and inline preparation from the washer to the anti-tacking stage.
and Sharp Corp., with greater image definition, Dow Jones reported.
Through the integration of the image carrier, a digital flexo plate has sharper image definition and steeper relief shoulders than conventional plates produced with film.
This highly sophisticated glass filter produces vibrant color, crisp text and crystal clear image definition that is much easier on the eye than conventional LCDs.
Washed-out color, poor image definition and the three letterboxed frames' tiny size further make "AKA" an ungainly visual experiment that will be well-nigh impossible to watch on home formats.
Minerals in paper and inks contribute to better image definition (dot shape) and equal or better performance with lower qualities of minerals.
When you need high-quality image definition, stochastic screening gives the sharpest detail.
The projector's intelligent image resizing circuit assures smooth outlines and sharp image definition no matter what the display.