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 be- coming a global standard. ICC profiles have been proposed as an International Organization for Standardization (ISO) standard. See also Profile.

IEEE 1394

Ahigh-speed transfer protocol defined by the Institute of Electrical and Electronics Engineers for connecting peripherals such as hard disks, MO drives, and digital cameras to a computer via a cable.

JPEG

Astandard 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.

Memory card

Used for storage of photographs in Nikon digital cameras.

Midpoint

Controls the output level for mid-tones in the original image. See also Tone, Tone curve.

NEF

An abbreviation of Nikon Electronic Format, an image file format developed by Nikon to sup- port high-resolution, twelve-bit RAW image data. In Windows, NEF files have the extension “.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.

151

Page 155
Image 155
Nikon 4 user manual 151, Icc