Summary

24 IT Essentials: PC Harware and Software Companion GuideFigure 7-18Types of ScannersAll-in-oneFlatbedDrumHandheldAs with printers, the features, quality, and speed of the different types of scanners vary.Scanners typically create an RGB image that can be converted into common image formatssuch as JPEG, TIFF, BMP, and PNG. An RGB image has three channels: red, green, andblue. RGB channels generally follow the color receptors of the human eye and are used incomputer displays and image scanners.Some scanners can create text documents using optical character recognition (OCR) software.OCR software is used to convert a scanned printed page into text that can be editedwith a word processor. A scanner’s resolution is measured in dots per inch (dpi). As withprinters, the higher the dpi, the better the image quality.To allow communication of data, the scanner and computer must have compatible interfaces.The interfaces and cables used for printers typically are the same as the interfacesand cables used for scanners, as shown in Figure 7-19.Describe All-in-One DevicesAn all-in-one device combines the functionality of multiple devices into one physical pieceof hardware. The devices may include media card readers and hard drives for storage. Allin-onedevices generally include these functions:■■■■ScannerPrinterCopierFax