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Scanner

A flat-bed device which uses charged coupled devices (CCDs) to translate an image from analog to digital. A scanner passes a moving beam of light over an image and receives data about the color or value of each spot in the image. These spots are assigned values from 0-256 so that computers can display them.

Screen Capture Programs

Screen capture programs allow a user to create graphic files of screen images. These graphics are useful when illustrating computer documentation.

In addition, some screen capture programs offer users the ability to record mouse and screen movement which is then saved in quicktime or AVI files.

List of screen capture programs for Mac and PC platforms.

Shade

When a color is mixed with white, gray, or black the results are called tints, shades, and tones.

A shade is a color which has been mixed with black. Brown is a shade of red, and olive is a shade of green.

A shade of a color can expand its expressive range by dulling its immediate impact and creating subtle variations of hue and meaning.

Software

Operating Instructions for specific task based applications. These instruc- tions are carried out by the computers processors. These include all packaged for use like image editing, word processing, databases, CAD- CAM, games, and so on. Software has to be written for a specific Computer OS.

Subtractive Color

The process of subtractive color mixing becomes important when wavelengths of light are reflected by an object. Not all objects reflect all colors of light, and consequently the color of the object is determined by the types of wavelengths it reflects. Because it reduces the number of wavelengths, the process is referred to as "subtractive".

The three primary colors of subtractive color mixing are cyan, magenta, and yellow which can be mixed to produce blue (cyan and magenta), red (magenta and yellow) and green (yellow and cyan). Notice that the secondary colors of additive color mixing are the primary colors of subtractive color mixing; this is because substances are more likely to reflect multiple wavelengths of light.

Pure blue is rare in nature because few substances will reflect just blue light; cyan is more common because many substances will reflect both blue and green.