EPSON AMERICA, INC.

EPSON

Product Support Bulletin

Subject: Image Editing Terms

 

Date: 6/5/91

PSB No: P-0078

Page(s): 1 of 3

Originator: RS

The following terms’ are used to describe image editing and grayscale in connection with scanners, monitors and printers.

Additive The colors produced by mixing colored light. The primary Primary Colors: additive colors are red, green and blue. The absence of color

 

produces black (0%); maximum intensity produces white (100%).

 

This principle is used in color monitors (RGB). By using 24 bits

 

per pixel it is possible to represent more than 16 million colors.

Aliasing:

The jagged diagonal lines that appear in low resolution mode.

 

Usually noticeable on characters like ‘A” and VV’!

Antialiasing :

The removal of the aliasing or step-like diagonal lines.

Brightness:

The balance of light and dark shades.

Continuous

The transition from light to dark or dark to light in a smooth

Tone:

uninterrupted progression. Laser and dot matrix printers do not

 

support continuous tones.

Contrast:

The range between the darkest and lightest shades of an image.

 

As contrast increases, the number of gray shades between black

 

and white decreases.

Cropping:

An operation that allows portions of an image to be selected.

 

Usually pertains to scanning technology.

Dithering:

A method of shading that uses black dots of varying density to

 

represent darker areas. This technology is used in devices that

 

only support black and white outputs.

DPI:

Abbreviation for dot per inch. The standard measurement of

 

resolution for all output devices. DPI describes the number of

 

pixels in an image.

‘Some terms taken from PC Publishing, Jan. 1990.