User`s guide

ScanShop User’s Guide - 1
Chapter 1: Introduction to Image Processing
Overview
In operation, ScanShop uses some underlying concepts that are basic to image
scanners, scanning, and processing the scanned image.
About Scanners
Image scanners are computer peripheral devices that scan and convert images
into digital data which are often referred to as bitmap or raster data. These
scanned image data can then be processed and reproduced by computers and
other devices.
The two popular kinds of scanners are the flatbed and the hand-held types. A
flatbed scanner has a moving carriage similar to that of a copier. A hand-held
scanner requires the user to drag the scanning device over the hard copy being
scanned.
All scanners have a photoelectric sensor and a light source. The sensor detects
the light that is reflected off the paper by the source and translates it into an
electric signal. The electrical signals are further translated into digital data
(rasters) which are in turn passed on to the computer. The computer then either
stores the image data or goes on to additional processing (for example, Optical
Character Recognition) to convert the data to another format.
About Resolution
Pixels (PIX [picture] ELEMENTS) are the dots that make up the screen image.
Resolution is a measure of the density of these pixels in the image, and it is
expressed in units of dpi (dots per inch). For any particular image, the higher the
dpi, the more pixels it takes to compose. There are four types of resolution that
are important to comprehend in understanding the scanning process: