C

calibrated monitor

The foundation from which all other color settings are determined. You can use a calibration device or the Adobe Gamma calibration package to calibrate your monitor.

calibration bars

The grayscale or color indicators that appear on printed output. When you print a CMYK color separation, the calibration bars appear only on the black plate. On a color image, the calibration bars are the color swatches printed at the sides of the image.

Camera Raw

A proprietary digital camera file format specific to each camera manufacturer and often to the make/model of a camera. Photoshop CS can process Camera Raw files from many popular digital cameras .

canvas

In Photoshop, the surface on which your image resides.

capture

Specific to digital video, the transfer of video information via FireWire to a computer environment for nonlinear editing.

channel

Analogous to a plate in the printing process, the foundation of an image. Some image types have only one channel, whereas other types have several channels. An image can have up to 24 channels. See also color channels .

Channel Mixer

A Photoshop feature that enables you to adjust the color information of each channel. You can establish color values on a specific channel as a mixture of any or all of the color channels brightness values.

Channels palette

The Photoshop palette that enables you to work with an image s color information, or channels, and create alpha channels.

Character palette

The Photoshop palette that contains settings for type, such as size , tracking, kerning, and leading.

chroma

See saturation .

CIE (Commission Internationale de l Eclairage)

An international organization of scientists who work with matters relating to color and lighting. The organization is also called the International Commission on Illumination.

clipping mask

Layers grouped together to create effects. In order to join two layers into a clipping group , the image on the bottom layer must be surrounded by transparency. When a layer is clipped, it fills the shape of the image on the layer below it so that it acts as a mask to clip the layer immediately above it.

clipping path

A path designed to be used as a mask in other applications. In Photoshop, the Clipping Paths option in the Paths palette menu enables you to create a path that will knock out the area outside the path when it is opened in another program. The interior portion of the path will be displayed, and the area outside the path will be transparent.

cloning

In Photoshop and other image-editing programs, a feature that enables you to copy a part of an image and use that copy to replace another part of the image. Cloning is accomplished with the Clone Stamp and Pattern Stamp tools.

CMYK

The colors used in process printing. Each color plate contains tiny dots of cyan, magenta , yellow, or black (CMYK). The densities of the colored dots on each plate influence the surrounding colors when the eye mixes them together.

CMYK color mode

A color mode that produces a full range of color by printing tiny dots of cyan, magenta, yellow, and black ink. Because the colored dots are so small, the eye mixes them together. The relative densities of groups of colored dots produce variations in color and tonality . CMYK is referred to as a subtractive color system.

CMYK image

A four-channel image containing a cyan, magenta, yellow, and black channel. A CMYK image is generally used to print color separations.

CODEC

An acronym for the compression/decompression process. Reducing storage requirements and the data rate required to retrieve video from a disk for decompression and playback.

color channels

Color information from an image. The number of color channels depends on the image s color mode. For example, Photoshop configures the information for an RGB image into three color channels (for the red, green, and blue components ) plus a composite RGB channel, which displays the entire image in full color. The computer processes the information in each channel as an independent grayscale image. Each pixel is assigned a specific numeric gray value, where black equals 0 and white equals 255. Each color channel is actually an 8-bit grayscale image that supports 256 shades of gray.

color correction

Changing the colors of pixels in an image ”including adjusting brightness, contrast, mid-level grays, hue, and saturation ”to achieve optimum printed results.

color depth

The number of shades that an imaging device can capture at once. The more bits there are per pixel, the more hues you can represent. The most common color depth, 8 bits per color, can produce 256 shades of each hue.

color management module (CMM)

The color management engine used by software to convert colors. The Adobe engine is ACE (Adobe Color Engine). Others you might encounter include Agfa, Apple ColorSync, Apple, Heidelberg, Imation, Kodak, Microsoft, and X-Rite.

color management policies

Policies that determine how Photoshop deals with color profiles when opening RGB, CMYK, or Grayscale files.

color mapping

Operations that can radically alter existing colors in an image. Color mapping provides the means to alter the basic characteristics of color while maintaining the image s detail.

color mode or model

A system of displaying or printing color. Photoshop supports the HSB color model and RGB, CMYK, Lab, Indexed, Duotone, Grayscale, Multichannel, and Bitmap color modes.

color separation (process)

An image that has been separated into the four process colors: cyan, magenta, yellow, and black (CMYK). The image is then printed on four separate plates, one for each of the process colors.

color working space

The colors produced by a specific device, such as a printer or monitor. Photoshop enables you to edit and store an image with a color space other than that of your monitor. The image is embedded with an ICC (International Color Consortium) profile that describes the working color space. The image can then move from one computer to another with its profile, and it can be displayed on two different monitors and appear the same.

colorimeter

A device used to calibrate a monitor by measuring the temperature of its color characteristics.

colorize

To convert gray pixels to colored pixels. Before a black-and-white image can be colorized in Photoshop, you must change its mode from Grayscale to a mode that supports color (RGB, CMYK, or Lab). By colorizing, you apply color to the image without affecting the lightness relationships of the individual pixels, thereby maintaining the image s detail.

conditional

A statement of a situation that must be met before the next step of an action can take place. You set both the condition situation and the steps to take if the condition is met. Inserting conditional steps is supported only in ImageReady CS.

continuous-tone image

An image containing gradient tones from black to white.

contrast

The tonal gradation between the highlights, midtones, and shadows in an image.

crop

To select part of an image and discard the unselected areas.

crop marks

The marks that are printed near the edges of an image to indicate where the image is to be trimmed .

Curves

A Photoshop color-adjustment tool that enables you to lighten, darken , add contrast to, and solarize images.