A device that can read text or illustrations printed on paper and translate the information into a form the computer can use. A scanner works by digitizing an image -- dividing it into a grid of boxes and representing each box with either a zero or a one, depending on whether the box is filled in. (For color and gray scaling, the same principle applies, but each box is then represented by up to 24 bits.) The resulting matrix of bits, called a bit map, can then be stored in a file, displayed on a screen, and manipulated by programs.
Optical scanners do not distinguish text from illustrations; they represent all images as bit maps. Therefore, you cannot directly edit text that has been scanned. To edit text read by an optical scanner, you need an optical character recognition (OCR ) system to translate the image into ASCII characters. Most optical scanners sold today come with OCRpackages.
Scanners differ from one another in the following respects:
Larger scanners include machines into which you can feed sheets of paper. These are called sheet-fed scanners. Sheet-fed scanners are excellent for loose sheets of paper, but they are unable to handle bound documents.
A second type of large scanner, called a flatbed scanner, is like a photocopy machine. It consists of a board on which you lay books, magazines, and other documents that you want to scan.
Overhead scanners (also called copyboardscanners) look somewhat like overhead projectors. You place documents face-up on a scanning bed, and a small overhead tower moves across the page.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »
Often times technologies start as hype but with time become adopted. As a developer or technologist, it is worth reading the hype and knowing the... Read More »Microsoft Hyper-V Network Virtualization Q&A
The top 5 Hyper-V questions with answers provided by Nirmal Sharma, a MCSEx3, MCITP and Microsoft MVP in Directory Services. Read More »Storage Trends: Solid State and Software Defined
Solid state drives and software defined storage are two leading trends in the rapidly growing storage market. Read More »
This Webopedia guide will show you how to create a desktop shortcut to a website using Firefox, Chrome or Internet Explorer (IE). Read More »Flash Data Storage Vendor Trends
Although it is almost impossible to keep up with the pace of ongoing product releases, here are three recent highlights in the flash data storage... Read More »15 Important Big Data Facts for IT Professionals
Keeping track of big data trends, research and statistics gives IT professionals a solid foundation to plan big data projects. Here are 15... Read More »