An image that uses different sized dots to represents light and dark areas.

Technical information packaged with an image file, which may be of use in displaying the image (e.g., length and width in pixels), identifying the image (e.g., name or source), or identifying the owner.

An RGB system or image containing more than 24 bits of colour data per pixel.

A wide range of density in a print or negative.

A light image that is intentionally lacking in shadow detail.

The white and nearly white parts of an image.

A bar graph of the number of pixels for each grey or RGB value in an image. The histogram helps you evaluate the tones in an image.

(Hue, Saturation, Brightness) A colour model that defines a colour by specifying its hue, saturation, and brightness.

Hue, Saturation, and Lightness. A method of describing any colour as a triplet of real values. The hue represents the colour or wavelength of the colour. It is sometimes called tone and is what most people think of as colour. The hue is taken from the standard colour wheel and is thus calibrated in degrees about the wheel. Saturation is the depth of the colour. It states how gray the colour is. It is real valued parameter from 0.0 to 1.0 with 0.0 indicating full gray and 1.0 representing pure hue. The lightness is how black or white a colour is. It also ranges from 0.0 to 1.0 but with 0.0 representing black and 1.0 white. A lightness of 0.5 is pure hue.

The aspect of colour that distinguished it from another colour (what makes a colour red, green, or blue). Hue is distinct from saturation, which measures the intensity of the hue.

The degree of contamination in a process colour ink or other pigments that alters its appearance from that of a perfect process colour. For example most magenta inks are contaminated with yellow, making them appear to be red, rather than purplish-red.