Tài liệu về scanner pdf

Scanner •Ngơ Thùy Trang •Nguyễn Ngọc Tiến •Trần Thị Thùy Hương •Lê Việt Tiên •Phạm Thị Như Quỳnh What is scanner? • An input device that scans (reads) the image as a series of dots and introduces the information into the computer’s memory (Infotech Glossary) Some definition • DPI • Electronic code • Digitized image DPI • DPI (dots per inch): density of computer or printer image: a measure of the density of the image produced by a computer screen or printer (Prodic Dictionary) Electronic code • A scanner ‘see’ images and converts the printed text or pictures into electronic codes that can be understood by the computer Electronic code Digitized image • A representation of a two-dimensional image using ones and zeros (binary) What is inside a scanner? • Colored filter • Rotating lamps • Software for scanner • OCR software Rotating lamps • The scanner operates by using rotating lamps which has a different colored filter Colored filter • It has different colors: red, green and blue Software for scanner • Software for scanner translates the API procedure calls into primitive commands • Some common scanner software: - SANE (Scanner Access Now Easy) - TWAIN - ISIS (Image and Scanner Interface Specification) - WIA (Windows Image Acquisition) (Wikipedia) OCR software • OCR (Optical Character Recognition) • OCR software let you easily convert images, such as digital photographs, scanned documents, printed books, etc into text Flatbed scanner • A scanner with a glass scanning surface on which objects are placed; similar to a photocopier (Infotech Glossary) How a flatbed scanner works? • 1: a flatbed scanner ‘see’ images and converts them into electronic codes How a flatbed scanner works? • 2: The scanning unit moves across the image to be scanned Process of scanning ChargeCoupled Devices a glass pane (platen) a bright light How a flatbed scanner works? • 3: It reads the image as a series of dots and then generates the digitized image How a flatbed scanner works? • 4: Digitized image is sent to computer and stored as a file Uses of Flatbed scanner You place a drawing, photograph or other printed document face down on the glass and close or lower the plastic cover When you activate the scan feature, a light shines from under the plastic and a copy of your paper appears on your monitor Thank you for your attention! ... Software for scanner • Software for scanner translates the API procedure calls into primitive commands • Some common scanner software: - SANE (Scanner Access Now Easy) - TWAIN - ISIS (Image and Scanner. .. text Flatbed scanner • A scanner with a glass scanning surface on which objects are placed; similar to a photocopier (Infotech Glossary) How a flatbed scanner works? • 1: a flatbed scanner ‘see’... using ones and zeros (binary) What is inside a scanner? • Colored filter • Rotating lamps • Software for scanner • OCR software Rotating lamps • The scanner operates by using rotating lamps which