Depth
of Field : The distance
between the closest and farthest objects in focus within a scene as viewed by
a lens at a particular focus.
Diffuse : Light that is reflected from an object's surface,
regardless of the angle from witch its viewed.
Dissolve : An animation effect that is a transition between
two sequences involving a fade from one directly to the other.
Dither : The mixing of adjacent pixels to simulate additional
colors when available colors are limited, such as on an 8-bit monitor or an
8-bit palette.
Dithering : One of many processes for reducing the total number
of colors present in an image while retaining visual fidelity. Dithering can
be done by interleaving pixels of selected colors to locally approximate the
desired color. Dithering can be applied to either a color or a grayscale color
space and may be necessary due to a limited number of colors available on the
display device.
Dodge : To bleach (lighten) an area of an image.
DPI
: (Dots per inch) A unit
that is used to measure the resolution of a printer or image setter. Dpi is
sometimes used to describe the input resolution of a scanner, but "ppi"
is the more accurate term.
Duotone : A grayscale image that is printed using two plates
to enhance its tonal depth.
EPS
: Encapsulated PostScript,
the file format based on Adobe PostScript. Primarily used to define vector graphics
(i.e., geometrical shapes), it can also be used to contain and provide instructions
for rendering image (i.e., pixel-based) data. In the case of PhotoShop, an optional
PICT or TIFF image for screen display is included too. EPS is a commonly used
format for moving files from one application to another and also for color separation.
Feather
: Fades an area over a specified number of pixels.
Fill/Flood Fill : These are techniques for coloring areas
bounded by line edges. The algorithms that fill interior-defined regions (the
largest connected region of pixels whose values are the same as a given starting
pixel) are called flood fill algorithms.
Filter : 1) An optical device that selectively attenuates
the intensity of light passing through it according to the light's properties.
Common filters attenuate light according to either wavelength or polarization
state.
2) An algorithm that selectively modifies the intensity or color of image data
according to the image's properties. 3) An element (software or hardware) which
takes in a stream of data and produces a stream of results, on average one output
for each input.
Foreground Color : The color that is applied when a painting
tool is used, type is created, or the stroke command is applied.
Four-color Process : The printing process that reproduces
colors by combining, cyan (C), magenta (M), yellow (Y), and black (K) inks.
This process is alternately called four-color printing, CMYK printing, or process
printing.
FPS : Frames Per Second. The rate at which animations are
displayed.
Frame : A still two-dimensional image. Often a frame is a
raster image as used in the frame buffer of a graphics display system. In computer
animation frames per second is a measurement of the number of still frames displayed
in one second to give the impression of a moving image.
Frame Rate : The frame rate of a video source is determined
by the speed at which it completes the rendering of a new image. This is limited
by both the speed at which image data can be created and the rate at which video
images can be presented on a display. For example the NTSC system redraws at
30Hz, PAL is 25Hz and computer displays are now usually 72-75Hz.
Frame Size : A term used to refer to the dimensions of the
array of pixels forming a frame of an animation, or alternatively the memory
requirement and hence indirectly the resolution and dimensions.
Gamma
: The values produced
by a monitor from black to white are nonlinear. If you graph the values, they
form a curve, not a straight line. Gamma defines the slope of that curve at
halfway between black and white. Gamma adjustment compensates for the nonlinear
tonal reproduction of output devices such as monitor tubes.
Gamut : The total range of colors produced by a device. A
color is said to be "out of gamut" when its position in one device's
color space cannot be directly translated into another device's color space.
GIF : Graphic Interchange Format. This file format is commonly
used on the internet.
Gradient Fill : In PhotoShop, a graduated blend between the
Foreground and Background colors that is produced using the Gradient tool.
Grayscale : A color space where colors are represented by
their luminance values only, i.e. saturation and hue are zero. An image that
contains black, white, and up to 256 shades of gray, but no color In PhotoShop,
Grayscale is a one-channel image mode.
Halftone
Screen : A pattern of
tiny dots that is used for printing an image to simulate continuous tones.
Hard Proof : The printed proof of a document created to preview
how colors will look when reproduced on a specific output device, usually a
commercial printing press. A hard proof may be produced using a laminate contract
proofing system (e.g., Imation MatchPrint) or a tightly calibrated digital printer
designed for proof creation.
Highlight : The area of a glossy object over which specular
reflection can be viewed. It is normally the color of the light source, not
of the object.
Histogram : A graph showing the number of pixels at each level
of brightness in an image.
HSB : A three-coordinate, device-independent color model.
The HSB coordinates define colors in terms of Hue, Saturation, and Brightness.
HSL/Hue-Saturation-Lightness : HSL, also known as HSI (Hue-Saturation-Intensity)
is a color space used to represent images. HSL is based on polar coordinates,
while the RGB color space is based on a three-dimensional Cartesian coordinate
system. Intensity is the vertical axis of the polar system, hue is the relative
angle and saturation is the planar distance from the axis. HSL is thought to
be more intuitive to manipulate than RGB space. For example, in the HSI space,
to change red to pink requires only changing the saturation parameter.
HSV/Hue-Saturation-Value : A color space that describes color
using three basis components: hue, saturation and brightness.
Hue : The wavelength of light of a pure color that gives a
color its name--such as red or blue--independent of its saturation or brightness.