Glossary
Scanning
| Image | Graphics
Scanning
| Image Resolution | The resolution of a bit-mapped image measured in pixels per inch. |
| Index Color | A method of displaying color images where the palette of available color is limited to 256 colors or fewer Layers. |
| DPI
(Dots Per Inch) |
The resolution of an output device. |
| PPI
(Pixels Per Inch) |
The resolution of a bitmapped image or image on computer. |
| UCR
(Under Color Removal) |
A method used to save ink costs. |
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CMYK |
The standard color model for professional printing applications. |
Image
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Alpha
Channel
|
In
Photoshop, stored mask and selection data in an image.
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Anti-aliasing
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A
method of adding pixels of intermediate colors along the edges of
images to get smoother transition from one color to another
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Bit
Depth
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The
measure of the number of colors that a monitor is capable of displaying
at one time.
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Channels
|
A
storage place for fundamental components of any Photoshop image.
There are 5 types, used for different things: Color, Mask, Quick
Mask, Layer Mask, and Alpha channels.
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Crop
|
The
process of removing unwanted areas from around an image or printed
page.
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Dithering
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A
method of simulating unavailable colors by using patterns of available
colors to create the appearance of continuous tone.
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Filter
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Used
to apply special effects to an image.
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Gamma
Adjustment
|
The
shifting of the middle values of an image along a curve so that
the shadows or highlights are compressed.
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Gamut
|
Possible
range of colors available to an input, display, or output device.
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Greyscale
|
An
image made up of multiple grey values.
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Halftone
|
Displays
a picture that represents the tonal range of a picture.
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Hue
|
Pure
colors along the spectrum with no black or white added.
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Image
Size
|
The
physical dimensions of an image.
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Layer
|
A
transparent overlay in a document that allows you to isolate various
portions of your image to allow the user to edit one layer without
disturbing the other layers.
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Layers
Palette
|
Provides
you with tools to control the management and characteristics of
layers
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Levels
|
The
grey values on a scale of 0 (black) to 255 (white).
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Line
Art
|
Black
and white art with no grey values.
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LPI
|
Lines
per inch, the resolution of the halftone screen.
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Marquee
|
A
tool that draws a broken line outline around an object when the
object has been selected.
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Mask
|
Consists
of selecting an area in an image so that the area alone can be altered
by an effect. Conversely, an inverse mask will allow the area outside
of the mask to be modified by the application of an effect.
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Noise
|
Pixels
added randomly to an image to give it the appearance of graininess.
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OCR
|
Optical
Character Recognition. Software that allows users to scan and recognize
printed text then convert images into electronic form to be directly
edited in word processors or other similar software.
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Pixel
|
A
single dot on a computer display.
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Pixel
Depth
|
The
number of bits of stored information available for each pixel in
the file (also known as bit resolution).
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PPI
|
Pixels
Per Inch; the resolution of a bitmapped image or image on computer.
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RGB
Color
|
Red,
Green, and Blue Color; The color displayed on a computer's monitor
by adding different quantities of red, green, and blue light to
create a wide range of possible color.
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Saturation
|
The
pureness of a color. Adding white or black to a color lowers its
saturation.
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Scaling
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The
process of changing the horizontal or vertical size of a selection.
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Shear
|
In
painting and drawing programs, the action of slanting an object
along a specific axis.
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Unsharp
Mask
|
A
filter used to accurately sharpen image detail.
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Common
Graphic Files Format
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PICT
(*.pict) |
Default
Picture file format used primarily for Macintosh image files. Usually
large in memory.
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Bitmap
(*.bmp) |
A
graphic image consisting of a matrix of dots (pixels). Photoshop
images are bitmapped images.
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TIFF
(*.tif) |
Tagged
Image File Format. File format used especially in printing and page
layout applications. Usually larger than GIF or JPEG files.
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PNG
(*.png) |
Portable
Network Graphics. An upcoming alternative to GIF's, currently have
limited support, but should become more popular as they offer better
results and better compression and more colors.
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GIF
(*.gif) |
Graphic
Interchange Format.. Popular file format for Web graphics. Most
commonly used for bitmap images composed of line drawings or blocks
of a few distinct colors. Supports transparency. Limited to 256
colors.
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JPEG
(*.jpg) |
Joint
Photographic Experts. Another popular file format for Web graphics.
Most commonly used for photographs and similar continuous-tone bitmap
images.
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