Fujitsu fi-4120C2 Operator's Manual page 120

Error diffusion
High-quality halftone (pseudo-grayscale) image production based on black-and-white
pixel binarization. A pixel's optical density and that of adjacent pixels are summed, with
black pixels relocated in their order of density as they relate to adjacent pixels. The pur-
pose of this technique is to minimize the average error between read and printed densi-
ties. Density data for adjacent pixels is modified by diffusing errors on the objective pixel
into several pixels, which are then binarized. This maintains high grayscale levels and
resolution during reading, while suppressing more patterns by dotted halftone images
such as newspaper photographs.
FCC
Acronym for "The Federal Communications Commission", an independent United States
government agency which is in charge of regulating interstate and international commu-
nications via radio, television, wire, satellite and cable. The Part 15 of the FCC regula-
tions mentioned in this manual is designed to prevent harmful interferences on radio
communication of radio receivers and other devices which radiate radio frequency
energy, and provides for the certification of radio receivers. It also provides the certifica-
tion of low power transmitters and the operation of certificated transmitters without a
license.
Feeds rollers
Rollers that feed documents through the ADF.
Filtering
A correction method that improves the read quality of handwritten documents. The read
quality of images written in pencil or ball-pointed pen depends on the reflective light
characteristics of the specific ink or lead used. Dropped pixels may produce outlines,
gaps, or thin, barely connected lines due to uneven optical density. Filtering detects
areas lighter than their surroundings and increases their density to improve image clarity.
Flat bed An input device of the scanner, where documents are placed and scanned.
Generally used for scanning pages out of a book, or paper that is out of the feeding
specification of the ADF. Also used to scan a small volume of documents by manual
operation.
Flat bed
An input device of the scanner, where documents are placed and scanned. Generally
used for scanning pages out of a book, or paper that is out of the feeding specification of
the ADF. Also used to scan a small volume of documents by manual operation.
GL-4