GLOSSARY^203
color, subtractive A system such as printing that creates colors by combining the absorption
capabilities of four basic colors: cyan, magenta, yellow, and black. See also color, additive.
color balance The overall accuracy of the hues in a photograph, particularly with reference to
white.
color depth The number of bits assigned to each pixel in the image and the number of colors that
can be created from those bits. See also bit depth.
color fringing A digital-imaging artifact caused when color-filtering arrays or patterns of photodi-
odes on image sensors conflict with visual information in a scene, causing discolorations along the
edges of some objects.
color intensity The brightness of a printed image controlled by the amount of ink applied to the
page; lighter images use less ink and darker images use more.
color management system (CMS) Software utilities to calibrate color on input and output
devices like displays, printers, and scanners. Color management systems control the accurate conver-
sion of colors from RGB to CMYK.
color temperature The warmth or coolness of light, measured in degrees Kelvin (K). Midday
daylight is about 5,500K. Light bulbs are about 2,900K, meaning they’re more orange or warm.
Color temperature is important to color balance.
CompactFlash memory Based on Personal Computer Memory Card International association
(PCMCIA) PC card specifications, CompactFlash measures 43mm ×36mm and is available with stor-
age capacities exceeding 8GB. Currently, the competition among CompactFlash makers is to pro-
duce cards that do a faster job of writing (saving) and reading (retrieving) data. Speeds are
expressed as a multiple of basic speed of the original CompactFlash (1X). Current speeds read as
much as 150X.
compression, lossless A file compression scheme that makes a file smaller without sacrificing
quality when the image is later uncompressed. Zip and GIF files use lossless compression.
compression, lossy A file compression scheme that reduces the size of a file by permanently
discarding some of the visual information. JPEG is the most common lossy compression format for
graphics.
compression ratio The ratio of the size of a compressed digital file to the original uncom-
pressed file. Ratios between 15:1 and 8:1 are the most often used in digital cameras. Highest quality
ratios are less than 5:1, non-lossy compression is 2:1 or less.
continuous tone An image, such as a film photo, that has a gradual range of tones without any
noticeable demarcation from one to the other.
contrast The difference between the dark and light areas of an image.
cropping An image editing technique that removes parts of the photo along the sides to eliminate
unwanted details.