Manual

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Glossary
Histogram
A bar graph showing the distribution of tones in an image. The horizontal axis shows tone
level (brightness), the vertical axis the number of pixels. The bars in the graph show the
number of pixels of a given brightness in the image. The histogram displayed in the Curves
window shows the distribution of tones for the currently selected channel, and can be used
for reference when editing curves. See also Tone, Tone curve.
ICC
The International Color Consortium, an international organization working to develop stan-
dards for color management and color management profiles. ICC profiles were developed for
the conversion of color space information between devices, and are now on their way to
becoming a global standard. ICC profiles have been proposed as an International Organiza-
tion for Standardization (ISO) standard. See also Profile.
IEEE 1394
A high-speed transfer protocol developed by the Institute of Electrical and Electronics Engi-
neers for connecting peripherals such as hard disks, MO drives, and digital cameras to a com-
puter via a cable.
JPEG
A standard graphic format designed by the Joint Photographic Experts Group. Images are
compressed using a discrete cosine transform that takes advantage of the properties of hu-
man vision, which is more sensitive to light in the lower wavelengths, to increase quantization
at lower frequencies. JPEG compression is “lossy,” meaning that information is lost when
images are compressed, leading to a drop in image quality. A lossless compression option is
also supported in some implementations. JPEG images can be compressed to as much as
100:1, though quality will be significantly reduced. At a compression ratio of 20:1, image
quality is not noticeably diminished.
LCD
Liquid Crystal Display. LCDs are notable for their thinness, lightness, and the fact that they
consume relatively little energy.
Midpoint
Controls the output level for mid-tones in the original image. See also Tone, Tone curve.
NEF
An abbreviation of Nikon Electronic Image Format, an image file format developed by Nikon to
support high-resolution, twelve-bit RAW image data. In Windows, NEF files have the exten-
sion “.nef”. NEF images can be opened and edited only in Nikon Capture. The advantage of
NEF is that while user settings such as curves and color balance are saved, they are not applied
to the original image data. NEF images may thus be edited and saved several times without
degrading or altering the original image. NEF files however require a relatively large amount
of storage space. See also RAW image.
Noise
Data in an image file that are not a part of the original image, the digital equivalent of film
grain. The presence of noise is reflected in a loss in image quality. Noise appears primarily in
dark areas of the image, and can be reduced by adjusting exposure or lighting to fill in shad-
ows.