Image Emphasis; Image Processing - Fujitsu fi-4220C2 Operator's Manual

Gamma
A unit of changes of images' brightness. It is expressed as a function of the electric input
power to devices (scanner, display, etc.) and an image's brightness. If the gamma rate is
larger than 1, the brightness of an image increases and vice versa. In order to adjust the
brithtness of an image close to the orignal, generally the gamma value is set to 1.
Gray scale
A method for realizing the gradation from black to white on the scanned image. For
example, when scanning monochrome documents, the computer recognizes the docu-
ments as sets of black and white dots. In the Gray scale method, each dot contains data
regarding density of black. The original gradation of the documents is realized as the
gradation of the density data.
Halftone processing
Any method used to reproduce a photograph which includes a shade as an image com-
posed of dots, namely, a binary image. Dithering and error diffusion processing are
examples of halftone processing.

Image emphasis

Density is decreased for lighter but not completely white areas adjacent to black areas.
Weakening this emphasis eliminates spot noise or produces softened images.

Image processing

An image is scanned with specified parameters.
Interface
The connection that allows communication from the computer to the scanner.
Inversion (Reverse-image reading)
In reverse-image reading, data is changed from black to white and vice versa.
IPC preset mode
While reading binary images, it is necessary to set the scanner according to the quality
of the sheet to be read. In this mode, these settings can be performed in advance by cor-
responding each setting to a pattern number.
fi-4220C2 Image Scanner Operator's Guide
GL-5