By-products of digital processing such as noise and JPEG compression, both of which will degrade image quality.

Square pixels can’t depict curved shape,s and when viewed in close-up they look like a staircase. Anti-aliasing filters, found between the camera lens and image sensor, lessen the effects of aliasing by reducing contrast, which has to be reinstated during image processing.

A bit is the smallest chunk of digital data, which can express two states. such as on or off, or if used to describe color, black or white.

All digital images are made from pixels arranged in a chessboard-like grid called a bitmap.

A byte is eight bits of digital data, expressing 256 different states or colors.

Stands for Charged Coupled Device. It is the light sensitive “eye” of a scanner and “film” in a digital camera.

Clipping occurs when image tone close to highlight and shadow is converted to pure white or black during scanning or exposure in-camera.

Stands for Cyan, Magenta, Yellow, and Black (called K so it is not confused with blue). It is an image mode used for litho reproduction. All magazines are printed with CMYK inks.

RGB, CMYK, and LAB are three different kinds of color spaces, each with a unique characteristic palette, but also limitations in terms of color reproduction.

Crunching digital data into smaller files is known as compression. Without physically reducing the pixel dimensions of an image, compression routines work by creating a smaller string of instructions to describe groups of pixels, rather than individual ones.

Curves are a versatile tool for adjusting contrast, color, and brightness by pulling or pushing a line from highlight to shadow.

A method of simulating complex colors or tones of gray using few color ingredients. Close together, dots of ink can give the illusion of new color.

Pipette-like icons that allow you to define color selection and tonal limits, such as highlights and shadows, by directly clicking on parts of the image.

A kind of digital printer that uses a CMYK color-infused dry ink sheet to pass color onto special printing paper.

Digital Print Order Format is a set of universal standards allowing you to specify printout options directly from a camera when connected to direct printing units such as Epson’s PictureMate range.

A duotone image is made from two different color channels chosen from the color picker. This technique is used to create subtly toned, monochromatic images.

A small software application that instructs a computer to operate an external peripheral device like a printer or scanner. Drivers are frequently updated but are usually available as a free download.

The measure of the brightness range in photographic materials and digital sensing devices. The higher the number, the greater the range. Professional scanners and media are able to display a full range from white to the deepest black.

The three- or four-letter/number code that appears at the end of a document name, preceded by a full stop—for example, landscape.tif. Extensions enable applications to identify file formats and enable cross-platform file transfer.

Images can be created and saved in many different file formats, such as JPEG, TIFF, or PSD. Formats are designed to let you package images for purposes such as email, printout, and Web use.

A fast data transfer system for high-resolution image files. Also known as IEEE1394.

The contrast of the midtone areas in a digital image.

Gamut is a description of the extent, or range, of a color palette used for the creation, display, or output of a digital image.

Grayscale mode is used to save black-and-white images. There are 256 steps from black to white in a grayscale image, just enough to prevent the appearance of banding to the human eye.

The brightest part of an image, represented by 255 on a 0–255 scale.

High-res images are generally made with a million or more pixels and are used to make high-quality printouts.

A graph that displays the range of tones present in a digital image as a series of vertical columns.

The International Color Consortium was founded by major manufacturers to develop color standards and cross-platform systems.

All digital images can be enlarged, or interpolated, by introducing new pixels to the bitmap grid. Interpolated images never have the same sharp quality or color accuracy of originals.

JPEG is an acronym for Joint Photographic Experts Group and it is a universal file format used for compressing images. Most digital cameras save images as JPEG files to make more efficient use of memory cards.

A common set of tools for controlling image brightness found in Adobe Photoshop Elements and many other imaging applications. Levels can be used for setting highlight and shadow points and for correcting camera exposure errors.

Low-res images are small in size, produce poor-quality printouts, and are only suitable for Web page display.

Megapixel is a measurement of how many pixels a digital camera can make. A bitmap image measuring 1800×1200 pixels contains 2.1 million pixels, made by a 2.1 megapixel camera.

Sometimes called true resolution, this refers to the uninterpolated pixel dimensions of an image.

A more lightfast inkset for inkjet printers, usually with a smaller color gamut than dye-based inksets. Used for producing prints for sale.

Taken from the words PICture ELement, a pixel is the building block of a digital image, like a single tile in a mosaic. Pixels are generally square in shape.

When a digital print is made from a lowres image, fine details appear blocky or pixellated because not enough pixels were used to describde complex shapes.

A plug-in is a piece of software that adds extra functions to your favorite application—like Adobe Photoshop.

The color reproduction characteristics of an input or output device. This is used by color management software to maintain color accuracy when moving images across computers and input/output devices.

Random Access Memory is the part of your computer that stores data during work in progress, helping you run applications and keep large images open.

A generic term for the file formats produced by different digital cameras, which retain flexibility in some shooting parameters.

Red, Green, and Blue mode is used for color images. Each separate color has its own channel of 256 steps, and pixel color is derived from a mixture of these three ingredients.

A Raster Image Processor translates vector graphics into bitmaps for digital output. RIPs can be both hardware and software and are used on large-format printers to maximize the use of consumables.

A fenced-off area created in an imaging application like Photoshop, which limits the effects of processing or manipulation.

The darkest part of an image, represented by 0 on the 0–255 scale.

A processing filter that increases contrast between pixels to give the impression of greater image sharpness.

A Thin Film Transistor monitor is the flat-panel type of computer screen.

Tagged Image File Format. A format that is the most widely used by professionals, as it is compatible with both Macs and PCs. A layered variation also exists, but this is less compatible.

This is the most sophisticated sharpening filter found in many applications.

Stands for Universal Serial Bus. This is a type of connector that allows for easier setup of peripheral devices.

Digital cameras can counteract the effects of color casts caused by artificial light with a white balance function.

In digital images, excessive light or overexposure causes white-out. Unlike film, where detail can be coaxed out of overexposed negatives with careful printing, white pixels can never be modified to produce lurking detail.