The process of reducing stair-stepping by smoothing edges where individual pixels are visible.
Suitable for long term stotage.
An undesirable degradation of an electronic image. Usually occurs during the electronic capture, manipulation, or output of an image.
The ratio of horizontal to vertical dimensions of an image. (35mm slide frame is 3:2, TV 4:3, HDTV 16:9, 4X5 film 5:4)
An artifact of color gradation in an image, when graduated colors break into larger blocks of a single color, reducing the "smooth" look of a
Defines the amount of information that can travel between two points in a specific time.
An image made up of dots, or pixels. Refers to the raw format of a raster image, in which the image consists of rows or pixels rather than vector coordinates.
The value of a pixel in an image, representing its lightness value from black to white. Usually defined as brightness levels ranging in value from 0
(black) to 255 (white).
Common term used for a device that can read the information from a “Memory card”. This device may be connected to the computer via the USB, serial, parallel ports or via a PCMCIA
CCD-Charged Coupled Device
A charged coupled device (CCD) converts light into proportional (analog) electrical current. The two main types of CCDs are linear arrays used in flatbed scanners, digital copiers, and graphic arts scanners, and area arrays used in camcorders, still-video cameras, digital cameras, and fast scanners.
One piece of information stored with an image. True color images, for instance, have three channels-red, green and blue.
The color of an image element (pixel). Chroma is made up of saturation + hue values, but separate from the luminance value.
Adjustment to overall color shifts, like those produced by filters.
An abbreviation for Complimentary Metal Oxide Semiconductor. In this case CMOS are light sensors that capture images taken by digital cameras. Usually they are found in high-end digital cameras with megapixel sensors.
CMYK (Cyan, Magenta,Yellow, Black)
One of several color encoding system used by printers for combining primary colors to produce a full-color image. In CMYK, colors are expressed by the "subtractive primaries" (cyan, magenta, yellow) and black. Black is called "K" or keyline since black, keylined text appears on this layer.
The process of correcting or enhancing the color of an image.
A type of storage card used in digital cameras to store images captured by the camera. The Compact Flash can then be erased when the images have been transferred or are no longer needed, the card can be erased and reused. It also fits into a PCMCIA adapter eliminating the need to connect the camera to some computer systems.
The reduction of data to reduce file size for storage. Compression can be "lossy" (such as JPEG) or "lossless" (such as TIFF LZW). Greater reduction is possible with lossy compression than with lossless schemes.
An image where brightness appears consistent and uninterrupted. Each pixel in a continuous tone image file uses at least one byte each for its red, green, and blue values. This permits 256 density levels per color or more than 16 million mixture colors.
A visual effect in an image as a result of low brightness resolution which appears as bands of sharp, distinct, brightness change. Very similar to banding.
Cropping is the traditional method for trimming photographs to fit a certain size.
The generic name for anything input to, output from, or stored in a computer. All data must be in digital format.
A method of dithering that randomly distributes pixels instead of using a set pattern.
Allows the user to zoom in on a subject beyond the range provided by the optical zoom lens. Digital zooming crops the center of the digital picture and resizes the new cropped picture to the size of the selected resolution.
The process of converting analog information into digital format for use by a computer.
A method for simulating many colors or shades of gray with only a few. A limited number of same-colored pixels located close together is seen as a new color.
The transfer of files or other information from one piece of computer equipment to another.
DPI (Dots Per Inch)
The measurement of resolution of a printer or video monitor based on dot density. For example, most laser printers have a resolution of 300 dpi, most monitors 72dpi, most PostScript imagesetters 1200 to 2450 dpi. The measurement can also relate to pixels in an input file, or line screen dots (halftone screen) in a prepress output film.
Analogous to film speed. A higher number means the camera sensor needs less light to make a good exposure. Higher numbers can help in situations of low light where flash may not be effective, e.g., large interiors in low light.
EPS (Encapsulated PostScript)
A graphic file format developed by Aldus, Adobe, and Altsys to allow exchange of PostScript graphic files (image information) between application programs.
Exif (Exchangable image format)
A file format used in digital cameras.
An optical system that uses glass or transparent plastic fibers as light transmitting media.
A type of program or data file. Some common image file formats include TIFF, PICT, and EPS.
A very fast external bus that supports data transfer rates of up to 400 Mbps. Firewire was developed by Apple and falls under the IEEE 1394 standard. Other companies follow the IEEE 1394 but have names such as Lynx and I-link.
FTP (File Transfer Protocol
An abbreviation for File Transfer Protocol and is a universal format for transferring files on the Internet.
A type of memory chip that can retain data after the system has been turned off. Its advantage is that digital cameras with flash memory can have batteries go "dead" and yet retain image data.
GIF File Format
Stands for Graphic Interchange Format, a raster oriented graphic file format developed by CompuServe to allow exchange of image files across multiple platforms.
The brightness of a pixel. The value associated with a pixel representing it's lightness from black to white. Usually defined as a value from 0 to 255, with 0 being black and 255 being white.
A term used to describe an image containing shades of gray as well as black and white.
An image reproduced through a special screen made up of dots of various sizes to simulate shades of gray in a photograph. Typically used for newspaper or magazine reproduction of images.
A term used to describe the entire range of colors of the spectrum; hue is the component that determines just what color you are using. In gradients, when you use a color model in which hue is a component, you can create rainbow effects.
A bar graph analysis tool that can be used to identify contrast and dynamic range image problems. Histograms are found in most software programs that are used to manipulate digital images.
A small graphic symbol or picture on a computer screen that represents a file, folder, disk, or command.
Capturing and manipulating images in order to enhance or extract information.
A method of increasing image resolution artificially. A digital camera relies on its internal hardware components to capture images. The hardware typically has a maximum image resolution-for instance, 1,280 x 1,024 pixels-that it can achieve. That resolution is known as the camera's optical resolution. Some cameras, however, use built-in software coding to capture images with resolution than exceeds the camera's hardware limitations. That resolution is known as the camera's interpolated resolution. Interpolation creates new pixels from those that exist and inserts them in-between the existing pixels to increase the image's overall resolution. Though interpolation can improve picture quality, interpolated images tend to look fuzzy when enlarged.
JFIF (JPEG File Interchange Format)
A minimal file format which enables JPEG bitstreams to be exchanged between a wide variety of platforms and applications.
The jagged stair-stepping effect often seen in images whose resolutions are so low that individual pixels are visible.
JPEG (Joint Photographic Experts Group)
A technique for compressing full-color bit-mapped
A (pronounced jay-peg) stands for Joint Photographic Experts Group. JPEG is a color image compression technique that reduces file sizes by eliminating redundant or unnecessary image data. Many digital cameras automatically save images using the JPEG format. JPEG and GIF (Graphics Interchange Format), another compression method, are the most commonly used image file formats on the World Wide Web.
The latest version of the JPEG standard that promises up to 20:1 lossless compression.
Reduces the size of files by creating an internal shorthand that rebuilds the data as it originally were before the compression. Thus, it is said to be non-destructive to image data when used.
A method of reducing image file size by throwing away unneeded data, causing a slight degradation of image quality. JPEG is a lossy compression method.
LPI (Lines per Inch)
The frequency of horizontal and vertical lines in a halftone screen.
The outline of dots created by the selection tool on an image when an operator is performing a task such as cropping, cutting, drawing a mask, etc.
A defined area used to limit the effect of image-editing operations to certain regions of the image. In an electronic imaging system, masks are drawn manually (with a stylus or mouse) or created automatically--keyed to specific density levels or hue, saturation and luminance values in the image. It is similar to photographic lith masking in an enlarger.
amount of computer memory consisting of about one million bytes. The actual value is 1,048,576 bytes.
One million pixels or more. The more pixels that exist in an image the higher the resolution and therefore the greater the quality of the image. Many new Kodak cameras are equipped with megapixel sensors.
A visible pattern that occurs when one or more halftone screens are misregistered in a color image.
A special effect used in motion pictures and video to produce a smooth transformation from one object or shape to another.
Nickel Metal Hydride Battery
Recommended for digital cameras, these batteries have high energy density (50% more than Ni-Cd) and can be charged over 500 times in their life cycle. They charge very fast and hold their energy longer than other batteries. When they are disposed of they have a low environmental impact
The Photo CD combines 35-mm film imaging and digital technology, so you can show your pictures on a television or computer monitor. Images can be transferred to a photo CD disc from new or existing developed 35-mm film, 35 mm slides, and other formats.
A graphics file format used primarily on Macintosh computers. PICT files can contain both object-oriented and bit-mapped graphics. There are two types: PICT I and PICT II. PICT II is the current standard and supports color up to 24-bit.
Pixel (PICture ELement)
The smallest element of a digitized image. Also, one of the tiny points of light that make up a picture on a computer screen.
Pixels per inch (PPI)
A measure of how much detail you see in your images.
(Portable Network Graphics) pronounced ping. A new standard that has been approved by the World Wide Web consortium to replace GIF because GIF uses a patented data compression algorithm. PNG is completely patent and license-free.
Raster images are made up of individual dots; each of which have a defined value that precisely identifies its specific color, size and place within the image. (Also known as bitmapped images.)
The final step of an image transformation or three-dimensional scene through which a new image is refreshed on the screen.
is an indication of digital image quality, which in turn is determined by the number of pixels. The higher the resolution, the better the image will look. A low-resolution digital image (at 640 x 480 pixels), for instance, may look great when displayed on the Internet but it can appear fuzzy when printed or enlarged. By comparison, high-resolution images, such as those at 1,280 x 1,024 pixels, contain enough pictorial information (sharp contrasts, rich colors, and picture details) to look good on the Internet as well as when printed or enlarged.
Short for Red, Green, and Blue; the primary colors used to simulate natural color on computer monitors and television sets.
The degree to which a color is undiluted by white light. If a color is 100 percent saturated, it contains no white light. If a color has no saturation, it is a shade of gray.
An optical device that converts images - such as photographs - into digital form so they can be stored and manipulated on computers. Different methods of illumination transmit light through red, green and blue filters and digitize the image into a stream of pixels.
Averaging pixels with their neighbors. It reduces contrast and simulates an out-of-focus image.
Square Pixels - Rectangular Pixels
Point and shoot digital cameras utilize camcorder technology. Camcorders use rectangular pixels because TV displays are rectangular. For computers square is better because computer monitors display square pixels. When you start with a rectangular pixel you have to "lob" off part of the pixel to display it. Essentially you lose image data and introduce artifacts with rectangular pixels.
Thermal Dye Sublimation Printer (or Diffusion Transfer)
A high resolution, continuous tone color printer. This technology allows the dot intensity to vary and to create many more colors than thermal wax. The dyes are vaporized at high heat and diffused across a small gap to the paper or transparency. Semi-transparent dots of cyan, magenta and yellow of varying intensities (usually 256 intensities) are overprinted to create more than 16 million hues. Thermal dye printers require special paper.
TIFF (Tagged Image File Format)
The standard file format for high-resolution bit-mapped graphics. TIFF files have cross-platform compatibility.
Color that has a depth of 24-bits and 16.7 million colors.
Protocol for exchanging information between applications and devices such as scanners and digital cameras. TWAIN makes it possible for digital cameras and software to "talk" with one another on PCs.
A process by which the apparent detail of an image is increased; generally accomplished by the input scanner or through computer manipulation.
USB (Universal Serial Bus)
is an abbreviation of Universal Serial Bus. USB is a standard port that enables you to connect external devices (such as digital cameras, scanners, and mice) to Windows 98 and Macintosh computers. The USB standard supports data transfer rates of 12Mbps (million bits per second), a vast improvement over the serial port standard it is beginning to replace. Aside from speed advantages, USB devices can be connected or disconnected without the need to restart the computer. Many USB devices can work on either a Windows 98 PC or a Mac, provided the device manufacturer offers connectivity software for both computer systems. Many of the latest digital cameras offer USB as well as serial connections.
Video Graphics Array- a resolution type that uses analog signals and is only capable of 16 colors @ 640x480 and 256 colors @320x200 respectively. VGA is considered to be the lowest common denominator in graphics display.
A feature of the DC 220 and the DC 260 that can automatically add date, time, or specific text to your images. The DC 260 offers the ability to add graphic or logo watermarks to images.
What You See Is What You Get. Refers to the ability to output data from the computer exactly as it appears on the screen.
Extended Graphics Array supports resolutions up to 1024 x 768 @256 colors.
A type of file compression that decreases the total size of a file and allow larger amounts of data to be transferred in fewer bytes. A zip file typically ends with a .zip extension.