GLOSSARY 349inch, but the printer may use 1,440 dots per inch to repre-
sent those 200 pixels per inch. Thus, the resolution of the
printer (1440 dpi) is not the same as that of the image that
it prints (200 ppi). Confusion results when dpi is used inter-
changeably with pixels per inch.
DVD, DVR, DV-RAM, DVD-RW A family of optical
storage discs that offer higher capacities (many gigabytes)
than the CD-ROM.
dye-sublimation printer A high-quality, continuous-
tone color printer. Each multicolored dot is created when
dyes of the basic colors are vaporized and then condensed
on a precise location on the printing paper or plastic sheet.
Because the amount of vaporization is highly changeable,
each condensed dot can be any one of 16 million colors,
and is thus called a continuous tone.
dynamic range A measurement of image density for a
scanner from 0 (pure white) to 4 (very black). The dynamic
range scale is logarithmic; a value of 3.0 is 10 times greater
than a value of 2.0. This scale is valuable when measuring
a scanner’s ability to capture detail in shadows on slides
and detail in highlights on negatives. The greater the
dynamic range, the greater the capability to capture detail
and not electronic noise. You may see the terms Dminand
Dmaxfor the minimum and maximum values of density
that a scanner can detect. If a scanner has a Dmin of .3
and a Dmax of 3.3, the total dynamic range would be 3.0.
emulsion The dye or silver halide layer on the plastic
(acetate) base that captures the light and image you shoot
through the camera. Emulsion is also the name used for
chemicals applied to photographic paper used in the dark-
room.
export The process of transferring data from one pro-
gram (for example, Adobe Photoshop) to another (for
example, Adobe Illustrator).
exposure latitude The capability of films or digital
cameras to accurately record a range of brightness values
in the scene being photographed. A film that can accu-
rately record scenes with extremely large brightness ranges
(for example, very bright highlights and very dark shad-
ows) is said to have a wide exposure latitude.
file format The unique and systematic way in which
information is organized in a file. Formats differentiate one
kind of file from another. Some common image file formats
include TIFF, JPEG, and PSD (Photoshop file).file A collection of data, such as an individual image,
saved on a computer storage device, and given a name to
assist in retrieval.
film recorder A device that records a digital image onto
photographic film.
film scanner A device that converts images from photo-
graphic film into digital form so they can be stored in a
computer and edited by software.
filter In imaging software, a filter is a command that
will produce special effects in an image. There are hundreds
of filters available as plug-in software for Adobe Photoshop.
flatbed scanner A digital scanner in which the object to
be scanned is held flat on a glass plate while the imaging
sensor (usually three CCDs) moves under it. A flatbed scan-
ner can be used as a camera to record three-dimensional
objects placed on its glass plate.
gamut The entire range of colors that a device (for exam-
ple, a digital camera or a printer) can record or reproduce.
GIF (Graphic Interchange Format) an image file for-
mat. GIF is an older bitmap file format. It is an 8-bit for-
mat, so GIF images have only 256 colors. It is the standard
format for creating non-photographic graphics for use on
the Internet.
gigabyte (GB) A measure of computer memory, disk
storage, or file size consisting of approximately one billion
bytes (a thousand megabytes). The actual value is
1,073,741,824 bytes.
grayscale image A digital image containing only black,
white, and shades of gray.
halftone A method of creating images on paper using a
grid of ink dots of various sizes to simulate shades of gray
in a photograph. For color printing, four grids of colored
dots (using the colors CMYK) are printed. Newspapers and
magazines use the halftone process to reproduce images.
hue One of the three terms used to exactly describe a
color (the others are brightness or value and saturation).
Informally, hue is the name of the color, such as red or
green-yellow. In a 360° color wheel, the hue can be exactly
specified as one of the points on the outside of the wheel.
import The process of bringing data into a program
from another program. For example, the images created by
many kinds of scanner software are imported into Adobe
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