Image Emphasis - Fujitsu M4097D Operator's Manual

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 purpose of this technique is to minimize the average error between read and printed densities.
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.
FB
In this manual, FB means flat bed.
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.
Front-side reading = Front-side scanning
Refers to reading the front side of the document, specifically in Duplex reading mode.
Halftone processing
Any method used to reproduce a photograph which includes a shade as an image composed of dots,
namely, a binary image. Dithering and error diffusion processing are examples of halftone processing.
Hexadecimal
A base-16 numbering system (also commonly referred to as hex numbers). Since a base-16 system
requires 16 digits, numbers 0 through 9 and letters A through F are used. It is convenient to express binary
numbers in hexadecimal because fewer digits are required.

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.
GL-3