Noise Removal; Operator Panel - Fujitsu fi-4220C2 Operator's Manual

Moire Patterns
Recurrent patterns on scanned images caused by incorrect settings of angles.

Noise removal

Isolated noise from an image appearing as black spots in white areas and voids in black
areas is removed to improve image quality.
Removes particles from the document image. Common particles include toner and fax
particles. Noise reduction works via an algorithm that removes pixels up to 5 x 5 dots
appart. A dot is 1/400 inch. A particle can be distinguished from a character as it is not
connected to another dot within 5 pixels.
OCR (optical character recognition)
Devices or technologies for identifying characters on documents and converting them
into text data that can be manipulated. The documents are checked by light and the dif-
ferences of light reflection are recognized as character shapes.

Operator panel

A panel consists of indicators and buttons. The operator panel is used to control scanner
operations such as, selecting features, and changing settings.
Optical sensor
A type of sensor for detecting multi feeding by light transmission. It also detects multi
feeding by recognizing differences in length of documents.
Outline extraction
The boundary between black and white areas is traced and the outline extracted for
closed areas.
Pad ASSY (Pad Assembly)
This part is used to separate a sheet of paper from a batch before feeding documents
into the ADF. This assembly is made out of rubber.
Photograph mode (White level follower OFF)
Selecting photograph mode makes brightness and contrast settings effective but pre-
vents the threshold from being set. With photograph mode, the darkness of image corre-
sponds to the black-pixel density, making it suitable in scanning images such as
photographs having gradations.
fi-4220C2 Image Scanner Operator's Guide
GL-7