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The scanner. scanner defined:. A scanner is a device that captures images from photographic prints, posters, magazine pages, and similar sources for computer editing and display. Scanners come in hand-held, feed-in, and flatbed types and for scanning black-and-white only, or color.
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scanner defined: A scanner is a device that captures images from photographic prints, posters, magazine pages, and similar sources for computer editing and display. • Scanners come in hand-held, feed-in, and flatbed types and for scanning black-and-white only, or color. • Scanners usually come with software, such as Adobe's Photoshop product, that lets you resize and otherwise modify a captured image.
How does a scanner work? • Scanners are the devices that read bar codes. • A scanner shoots pulses of light. • If it falls on a light area, a zero (0) is read. • If it falls on a dark area, it reads a one (1). • Scanning the bar code generates a string of zeros and ones. • This pattern of zeros and ones represents the characters encoded. • The scanner software, or firmware, translates or decodes the strings into characters. • The scanner must be able to shoot a straight line across the bars and spaces.
THE Scanner IN THE PAST AND NOW • Talking about a couple of years back, the scanners used to be expansive and less appealing on the image quality. Leave alone the text as it used to be almost indescribable with the scanned image. • Now the scanners today are based on high image quality and are suitable to every budget. • There are now different types of scanners which vary according to the needs of its users and have evolved around them only.
Types of Scanner 1-Drum ScannersDrum scanners capture image information using photo multiplier tubes (PMT) technology unlike the charged coupled device (CCD) used in flatbed scanners and film scanners.
2- Flatbed scanner Another type of scanner is the flatbed scanner. A flatbed scanner is usually made of a glass pane, which is illuminated with a bright light found underneath, and a moving optical CCD or CIS array.
3-Hand scanner A Hand scanner is a manual device that is dragged across the surface of the image to be scanned. Scanning documents in this manner is difficult as this requires a steady hand, to avoid uneven scanning rate that would produce distorted images.
Advantages & Disadvantages advantages:1) Scans anything.2) light and portable.3) Old document can be kept in digital form.4) Fast and convenient to have a copy done.disadvantages:1) Only can scan on the surface but not above it.2) Quality of scan not the same as original .
Thank s All for attention