Glossary
ACR Adobe Camera Raw.
Additive color A color system where the primaries of red, green and blue mix to form the other colors.
Adjustment layer Image adjustment placed on a layer.
Adobe Camera Raw Adobe’s own Raw conversion utility.
Adobe gamma A calibration and profiling utility supplied with Photoshop.
Adobe Photo Downloader Adobe’s download utility used for transferring photos from card or camera to computer. The utility ships with Bridge.
Algorithm A sequence of mathematical operations.
Aliasing The display of a digital image where a curved line appears jagged due to the square pixels.
Alpha channel Additional channel used for storing masks and selections.
Analyze/Analysis To examine in detail.
Anti-aliasing The process of smoothing the appearance of a curved line in a digital image.
APD Adobe Photo Downloader.
Aperture A circular opening in the lens that controls light reaching the film.
Area array A rectangular pattern of light-sensitive sensors alternately receptive to red, green or blue light.
Artifacts Pixels that are significantly incorrect in their brightness or color values.
Aspect ratio The ratio of height to width. Usually in reference to the light-sensitive area or format of the camera.
Bit Short for binary digit, the basic unit of the binary language.
Bit depth Number of bits (memory) assigned to recording color or tonal information.
Bitmap A one-bit image, i.e. black and white (no shades of gray).
Black and White A color to grayscale adjustment feature. As well as customized mapping of colors to gray the feature can tint monochromes as well.
Blend mode The formula used for defining the mixing of a layer with those beneath it.
Bridge Adobe’s sophisticated file browsing and organization program that ships with Photoshop.
Brightness The value assigned to a pixel in the HSB model to define the relative lightness of a pixel.
Byte Eight bits. The standard unit of binary data storage containing a value between 0 and 255.
Captured A record of an image.
CCD Charge Coupled Device. A solid-state image pick-up device used in digital image capture.
Channels The divisions of color data within a digital image. Data is separated into primary or secondary colors.
Charge Coupled Device See CCD.
CIS Contact Image Sensor. A single row of sensors used in scanner mechanisms.
Clipboard The temporary storage of something that has been cut or copied.
Clipping group Two or more layers that have been linked. The base layer acts as a mask, limiting the effect or visibility of those layers clipped to it.
Cloning Tool A tool used for replicating pixels in digital photography.
CMOS Complementary Metal Oxide Semiconductor. A chip used widely within the computer industry, now also frequently used as an image sensor in digital cameras.
CMYK Cyan, Magenta, Yellow and black (K). The inks used in four-color printing.
Color fringes Bands of color on the edges of lines within an image.
Color fringing See Color fringes.
Color gamut The range of colors provided by a hardware device, or a set of pigments.
Color Picker Dialog box used for the selection of colors.
Color space An accurately defined set of colors that can be translated for use as a profile.
ColorSync System level software developed by Apple, designed to work together with hardware devices to facilitate predictable color.
Complementary metal oxide semiconductor See CMOS.
Composition The arrangement of shape, tone, line and color within the boundaries of the image area.
Compression A method for reducing the file size of a digital image.
Constrain proportions Retains the proportional dimensions of an image when changing the image size.
Contact image sensor See CIS.
Context The circumstances relevant to something under consideration.
Continuous tone An image containing the illusion of smooth gradations between highlights and shadows.
Contrast The difference in brightness between the darkest and lightest areas of the image or subject.
CPU Central Processing Unit, used to compute exposure.
Crash The sudden operational failure of a computer.
Crop Reduce image size to enhance composition or limit information.
Curves Control for adjusting tonality and color in a digital image.
DAT Digital Audio Tape. Tape format used to store computer data.
Default The settings of a device as chosen by the manufacturer.
Defringe The action of removing the edge pixels of a selection.
Density The measure of opacity of tone on a negative.
Depth of field The zone of sharpness variable by aperture, focal length or subject distance.
Descreen The removal of half-tone lines or patterns during scanning.
Device An item of computer hardware.
Device dependent Dependent on a particular item of hardware. For example, referring to a color result unique to a particular printer.
Device independent Not dependent on a particular item of hardware. For example, a color result that can be replicated on any hardware device.
Digital audio tape See DAT.
Digital image A computer-generated photograph composed of pixels (picture elements) rather than film grain.
Digital Negative format Adobe’s open source Raw file format.
DNG Adobe’s Digital Negative format.
Download To copy digital files (usually from the Internet).
Dpi Dots per inch. A measurement of resolution.
Dummy file To go through the motions of creating a new file in Photoshop for the purpose of determining the file size required during the scanning process.
Dye sublimation print A high-quality print created using thermal dyes.
Dyes Types of pigment.
Edit Select images from a larger collection to form a sequence or theme.
Editable text Text that has not been rendered into pixels.
Eight-bit image A single-channel image capable of storing 256 different colors or levels.
Evaluate Assess the value or quality of a piece of work.
Exposure Combined effect of intensity and duration of light on a light-sensitive material or device.
Exposure compensation To increase or decrease the exposure from a meter-indicated exposure to obtain an appropriate exposure.
Feather The action of softening the edge of a digital selection.
File format The code used to store digital data, e.g. TIFF or JPEG.
File size The memory required to store digital data in a file.
Film grain See Grain.
Film speed A precise number or ISO rating given to a film or device indicating its degree of light sensitivity.
F-numbers (f-stops) A sequence of numbers given to the relative sizes of aperture opening. F-numbers are standard on all lenses. The largest number corresponds to the smallest aperture and vice versa.
Format The size of the camera or the orientation/shape of the image.
Frame The act of composing an image. See Composition.
Freeze Software that fails to interact with new information.
FTP software File Transfer Protocol software is used for uploading and downloading files over the Internet.
Galleries A managed collection of images displayed in a conveniently accessible form.
Gaussian Blur A filter used for defocusing a digital image.
GIF Graphics Interchange Format. An 8-bit format (256 colors) that supports animation and partial transparency.
Gigabyte A unit of measurement for digital files, 1024 megabytes.
Grain Tiny particles of silver metal or dye that make up the final image. Fast films give larger grain than slow films. Focus finders are used to magnify the projected image so that the grain can be seen and an accurate focus obtained.
Gray card Card that reflects 18% of incident light. The resulting tone is used by light meters as a standardized midtone.
Grayscale An 8-bit image with a single channel used to describe monochrome (black and white) images.
Half-tone A system of reproducing the continuous tone of a photographic print by a pattern of dots printed by offset litho.
Hard copy A print.
Hard drive Memory facility that is capable of retaining information after the computer is switched off.
HDR High Dynamic Range image.
High Dynamic Range A picture type that is capable of storing 32 bits per color channel. This produces a photo with a much bigger possible brightness range than found in 16- or 8-bit per channel photos. Photoshop creates HDR images with the Merge to HDR feature.
Highlight Area of subject receiving highest exposure value.
Histogram A graphical representation of a digital image indicating the pixels allocated to each level.
Histories The memory of previous image states in Photoshop.
History Brush A tool in Photoshop with which a previous state or history can be painted.
HTML HyperText Markup Language. The code that is used to describe the contents and appearance of a web page.
Hue The name of a color, e.g. red, green or blue.
Hyperlink A link that allows the viewer of a page to navigate or ‘jump’ to another location on the same page or on a different page.
ICC International Color Consortium. A collection of manufacturers including Adobe, Microsoft, Agfa, Kodak, SGI, Fogra, Sun and Taligent who came together to create an open, cross-platform standard for color management.
ICM Image Color Management. Windows-based software designed to work together with hardware devices to facilitate predictable color.
Image Color Management See ICM.
Image setter A device used to print CMYK film separations used in the printing industry.
Image size The pixel dimensions, output dimensions and resolution used to define a digital image.
Infrared film A film that is sensitive to the wavelengths of light longer than 720 nm, which are invisible to the human eye.
Instant capture An exposure that is fast enough to result in a relatively sharp image free of significant blur.
International Color Consortium See ICC.
Interpolated resolution Final resolution of an image arrived at by means of interpolation.
Interpolation Increasing the pixel dimensions of an image by inserting new pixels between existing pixels within the image.
ISO International Standards Organization. A numerical system for rating the speed or relative light sensitivity of a film or device.
ISP Internet Service Provider, allows individuals access to a web server.
Jaz A storage disk capable of storing slightly less than 2 GB, manufactured by Iomega.
JPEG (.jpg) Joint Photographic Experts Group. Popular image compression file format.
Jump To open a file in another application.
Juxtapose Placing objects or subjects within a frame to allow comparison.
Kilobyte 1024 bytes.
LAB mode A device-independent color model created in 1931 as an international standard for measuring color.
Lasso Tool Selection Tool used in digital editing.
Latent image An image created by exposure onto light-sensitive silver halide ions, which until amplified by chemical development is invisible to the eye.
Latitude Ability of the film or device to record the brightness range of the subject.
Layer A feature in digital editing software that allows a composite digital image where each element is on a separate layer or level.
Layer mask A mask attached to a layer that is used to define the visibility of pixels on that layer.
Layer Stacks A group of Photoshop layers that have to be converted into a Smart Object for the purposes of performing image analysis on the differences between the picture content of each layer.
LED Light-Emitting Diode. Used in the viewfinder to inform the photographer of exposure settings.
Lens An optical device usually made from glass that focuses light rays to form an image on a surface.
Levels Shades of lightness or brightness assigned to pixels.
Light cyan A pale shade of the subtractive color cyan.
Light magenta A pale shade of the subtractive color magenta.
LiOn Lithium ion. Rechargeable battery type.
Lithium ion See LiOn.
LZW compression A lossless form of image compression used in the TIFF format.
Magic Wand Tool Selection Tool used in digital editing.
Magnesium lithium See MnLi.
Marching ants A moving broken line indicating a digital selection of pixels.
Marquee Tool Selection Tool used in digital editing.
Maximum aperture Largest lens opening.
Megabyte A unit of measurement for digital files, 1024 kilobytes.
Megapixels More than a million pixels.
Memory card A removable storage device about the size of a small card. Many technologies available result in various sizes and formats. Often found in digital cameras.
Merge to HDR Photoshop’s feature for creating HDR images from a series of photos with bracketed exposures.
Metallic silver Metal created during the development of film, giving rise to the appearance of grain. See Grain.
Minimum aperture Smallest lens opening.
MnLi Magnesium lithium. Rechargeable battery type.
Mode (digital image) RGB, CMYK, etc. The mode describes the tonal and color range of the captured or scanned image.
Moiré A repetitive pattern usually caused by interference of overlapping symmetrical dots or lines.
Motherboard An electronic board containing the main functional elements of a computer upon which other components can be connected.
Multiple exposure Several exposures made onto the same frame of film or piece of paper.
Negative An image on film or paper where the tones are reversed, e.g. dark tones are recorded as light tones and vice versa.
NiCd Nickel cadmium. Rechargeable battery type.
Nickel cadmium See NiCd.
Nickel metal hydride See NiMH.
NiMH Nickel metal hydride. Rechargeable battery type.
Noise Electronic interference producing white speckles in the image.
Non-destructive editing An editing approach that doesn’t alter the original pixels in a photo throughout the enhancement process. Typically used for Raw processing or in techniques that make use of Smart Object technology.
Non-imaging To not assist in the formation of an image. When related to light it is often known as flare.
ODR Output Device Resolution. The number of ink dots per inch of paper produced by the printer.
Opacity The degree of non-transparency.
Opaque Not transmitting light.
Optimize The process of fine-tuning the file size and display quality of an image or image slice destined for the web.
Out of gamut Beyond the scope of colors that a particular device can create.
Output device resolution See ODR.
Path The outline of a vector shape.
PDF Portable Document Format. Data format created using Adobe software.
Pegging The action of fixing tonal or color values to prevent them from being altered when using Curves image adjustment.
Photomerge Adobe’s own panoramic stitching utility.
Photo multiplier tube See PMT.
Photoshop Document The native file format used by Photoshop.
Piezoelectric Crystal that will accurately change dimension with a change of applied voltage. Often used in inkjet printers to supply microscopic dots of ink.
Pixel The smallest square picture element in a digital image.
Pixelated An image where the pixels are visible to the human eye and curved lines appear jagged or stepped.
PMT Photo Multiplier Tube. Light-sensing device generally used in drum scanners.
Portable Document Format See PDF.
Pre-press Stage where digital information is translated into output suitable for the printing process.
Primary colors The three colors of light (red, green and blue) from which all other colors can be created.
Processor speed The capability of the computer’s CPU measured in megahertz.
PSD Photoshop Document format.
Quick Mask mode Temporary alpha channel used for refining or making selections.
Quick Selection Tool A selection tool added to Photoshop in version CS3 that tries to predict the shape of the selection as you draw. The feature takes into account tone, color, texture and shape of the underlying photo as it creates the selection.
RAID Redundant Array of Independent Disks. A type of hard disk assembly that allows data to be simultaneously written.
RAM Random Access Memory. The computer’s short-term or working memory.
Redundant array of independent disks See RAID.
Reflector A surface used to reflect light in order to fill shadows.
Refraction The change in direction of light as it passes through a transparent surface at an angle.
Resample To alter the total number of pixels describing a digital image.
Resolution A measure of the degree of definition, also called sharpness.
RGB Red, Green and Blue. The three primary colors used to display images on a color monitor.
Rollover A web effect in which a different image state appears when the Viewer performs a mouse action.
Rubber Stamp A tool used for replicating pixels in digital imaging. Also called Clone Stamp Tool.
Sample To select a color value for analysis or use.
Saturation (color) Intensity or richness of color hue.
Save a Copy An option that allows the user to create a digital replica of an image file but without layers or additional channels.
Save As An option that allows the user to create a duplicate of a digital file but with an alternative name, thereby protecting the original document from any changes that have been made since it was opened.
Scale A ratio of size.
Scratch disk memory Portion of hard disk allocated to software such as Photoshop to be used as a working space.
Screen real estate Area of monitor available for image display that is not taken up by palettes and toolbars.
Screen redraws Time taken to render information being depicted on the monitor as changes are being made through the application software.
Secondary colors The colors cyan, magenta and yellow, created when two primary colors are mixed.
Sharp In focus. Not blurred.
Single lens reflex See SLR camera.
Slice Divides an image into rectangular areas for selective optimization or to create functional areas for a web page.
Slider A sliding control in digital editing software used to adjust color, tone, opacity, etc.
SLR camera Single Lens Reflex camera. The image in the viewfinder is essentially the same image that the film will see. This image, prior to taking the shot, is viewed via a mirror that moves out of the way when the shutter release is pressed.
Smart Filter An extension of the Smart Object technology that allows the non-destructive application of Photoshop filters to an image.
Smart Object Technology first introduced in Photoshop CS2 that maintains the original form of an embedded image but stills allows it to be edited and enhanced. Smart Objects are used in many non-destructive editing or enhancement techniques.
Snapshot A record of a history state that is held until the file is closed.
Soft proof The depiction of a digital image on a computer monitor used to check output accuracy.
Software A computer program.
Stack Several photos grouped together in the Bridge workspace.
Subjective analysis Personal opinions or views concerning the perceived communication and aesthetic value of an image.
Subtractive color A color system where the subtractive primary colors yellow, magenta and cyan mix to form all other colors.
System software Computer operating program, e.g. Windows or Mac OS.
Tagging System whereby a profile is included within the image data of a file for the purpose of helping describe its particular color characteristics.
Thematic images A set of images with a unifying idea or concept.
TIFF Tagged Image File Format. Popular image file format for desktop publishing applications.
Tone A tint of color or shade of gray.
Transparent Allowing light to pass through.
Tri-color A filter taking the hue of either one of the additive primaries red, green or blue.
True resolution The resolution of an image file created by the hardware device, either camera or scanner, without any interpolation.
TTL meter Through-The-Lens reflective light meter. This is a convenient way to measure the brightness of a scene as the meter is behind the camera lens.
Tweening Derived from the words in betweening – an automated process of creating additional frames between two existing frames in an animation.
UCR Under Color Removal. A method of replacing a portion of the yellow, magenta and cyan ink, within the shadows and neutral areas of an image, with black ink.
Under color removal See UCR.
Unsharp Mask See USM.
Unsharp Mask filter A filter for increasing apparent sharpness of a digital image.
URL Uniform Resource Locator. The unique web address given to every web page.
USM Unsharp Mask. A process used to sharpen images.
Vanishing Point A Photoshop feature designed to allow the manipulation of photos within a three-dimensional space.
Vector graphic A resolution-independent image described by its geometric characteristics rather than by pixels.
Video card A circuit board containing the hardware required to drive the monitor of a computer.
Video memory Memory required for the monitor to be able to render an image.
Virtual memory Hard drive memory allocated to function as RAM.
Visualize To imagine how something will look once it has been completed.
Workflow Series of repeatable steps required to achieve a particular result within a digital imaging environment.
Zip An older style storage disk manufactured by Iomega, available in either 100 MB or 250 MB capacity.
Zoom Tool A tool used for magnifying a digital image on the monitor.