optical scannerA 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 OCR packages.
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 copyboard scanners) look somewhat like overhead projectors. You place documents face-up on a scanning bed, and a small overhead tower moves across the page.
- Enterprise Mobility Exchange results show continued growth and emphasis on mobility. CIOInsight breaks down the numbers here. »
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »
From the widest view, everything that we include under the heading of mobile has irrevocably changed IT's relationship with the rest of the... Read More »Choosing an Enterprise Storage Implementation
When you deploy a new enterprise storage system, you must decide whether to design and build your own storage system or to utilize a cloud-based... Read More »Big Data Analytics Expert Predictions
In this Webopedia Did You Know...? article we look at three big data expert predictions for 2014. Read More »
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 »Enterprise Storage Vendors
There's a number of vendors that sell enterprise storage hardware or offer cloud-based enterprise storage. View Webopedia's Enterprise storage... Read More »50 Cloud Computing Terms Defined
From planning a private cloud project to finding an online cloud storage provider, Webopedia's A-Z Cloud Computing Glossary will help you... Read More »