CCD: Charged Coupled Device, a light sensitive chip used for image gathering. In their normal condition these are greyscale devices. To create color a color pattern is laid down on the sensor pixels, using RGBG color mask. (Red, Green, Blue, and Green) The extra Green is used to create contrast in the image. The CCD Pixels gather the color from the light and pass it to the shift register for storage. * CCD are analog sensors, the digitizing happens when the electrons are passed through the A to D converter. The A to D converter converts the analog signal to a digital file or signal.

CCITT Group III: Data compressed in one dimension yielding an average data reduction of about 5:1 or 6:1. The most common implementation of CCITT Group III is the data reduction circuit found in FAX machines. This technique is also known as "run length encoded."

CCITT Group IV: Compression in two dimensions yielding an average data reduction of 25:1 or better. CCITT Group IV compression requires the execution of 80-million bit oriented operations. The resulting compressed file is roughly the same size as a vector file consisting of graphics.

Charged Coupled Device: A light sensitive chip used for image gathering. In their normal condition these are greyscale devices. To create color a color pattern is laid down on the sensor pixels, using RGBG color mask. (Red, Green, Blue, and Green) The extra Green is used to create contrast in the image. The CCD Pixels gather the color from the light and pass it to the shift register for storage. CCD are analog sensors, the digitizing happens when the electrons are passed through the A to D converter. The A to D converter converts the analog signal to a digital file or signal. 

CMYK: Cyan, Magenta, Yellow, Black; These are the printer colors used to create color prints. Most Color Printers, Ink-Jet, Laser, Dye-Sublimation, Thermal, and Crayon printers use these as their printer colors. (This is one of the color management problems for computers. Converting RGB files to CMYK files cause´s color shifts.) When used by a printer the CMYK is also known as a reflective color since it is printed on paper, or reflective films

Compression: Process of compacting digital data, images and text. Software algorithms search the raster image to build a greatly condensed (from a file storage perspective) format of the image. In the case of CCITT Group IV, the file size reduction is about 25:1. The actual compression factor is greatly dependent upon the quality of the scan and upon the density of the information.