Scanning devices read data or information from a physical source such as a written document, a price tag, or a picture. Three basic types: optical -- text and image; Barcode – wand readers and platform scanners; Character mark recognition – special characters
The scanner record the light and dark areas as well as the color of the source document. Flatbed scanners are like a copy machine. The source is place on top of the device to scan. Portable scanners make direct contact with the source material and is dragged by hand across it.
The photoelectric scanners are usually wand readers(portable handheld scanner) or platform scanners (mounted to a platform like a counter). UPC is a system by which every product is uniquely identified by manufacturer code and product code. Scanners read the UPC and lookup the item in a database to retrieve information, such as price.
Character and mark recognition devices MICR - used by banks to read magnetically encoded characters on check. The ink is mixed with magnetic particles. OCR - specially preprinted characters are read by OCR devices such as wand scanners such as seen in retail stores. OMR - devices sense the presence or absence of marks, common for test scoring such as the SAT and GRE test.
Character and mark recognition devices MICR - used by banks to read magnetically encoded characters OCR - specially preprinted characters are read by OCR devices such as wand scanners OMR - devices sense the presence or absence of marks, common for test scoring
Group Members :Satnam 25Kabita 26Aishwarya 27 1
Copy data from a sourceScanners take paper and convert it into a bitmap Types of scanners Optical scanner Bar code readers Character and Mark recognition 2
Convert text or drawings into machine readable format Can be displayed, printed, or stored Types of optical scanners Flatbed scanner Source placed on glass surface Image scanned from below Portable scanner Handheld device that slides across source 3
Flatbed scannerIf we talk about scanners, thus we mean usually flatbed scanner.The scan documents (texts, photo, diagrams etc..) are put on aglass plate like a copier, under which a carriage with an exposureitem and the read head moves. Then the picture is scanned Thepicture information is entered by a CCD (Charge CoupleDevice). CCDs are semiconductor chips, with an array of photo-sensitive cells, which are used for the transformation fromelectromagnetic waves of light into electrical signals. 4
Photoelectric scanner Using Optical Recognition, a light beam scans the item and changes it into electrical impulses for processing Contain photoelectric cells that read bar codes Read bar codes Alternating black & white vertical bars Universal Product Code (UPC) Seen in grocery stores, retail stores 5
Magnetic-ink character recognition (MICR) Reads magnetically encoded characters Optical-character recognition (OCR) Optical character recognition (OCR) converts bitmap back into text • different fonts create problems for simple “template matching” algorithms • more complex systems segment text, decompose it into lines and arcs, and decipher characters that way Optical-mark recognition (OMR) Senses presence or absence of marks 6
A flatbed scanner scans one sheet at a time by laying the sheet face down on the bed of the scanner Sheetfed scanner use motorized rollers to feed the document across the scanning mechanism Handheld scanner-portable device that requires users to pass the scanning element over the item to be scanned 7
Bar codes-each product has a unique product code (UPC) represented by a pattern of bars Bar code scanner scans the bars using reflected light which is then processed to retrieve product information assigned to that bar code Handwriting Recognition 8
Scanners are typically envisioned as connected to a co- located host computer. Submitting “Jobs” to network scanners is unnatural since a walk-up user must be present to submit the originals anyway. Jobs may be most naturally started at the scanner and not at a workstation. Will be more prevalent as networked MFPs provide scanning capability. 9
Archive-Communicate recording a facsimile of an image, such as a form or a signature for storage, transmission or reproduction. Parameters and area probably well defined, fidelity important. Includes Copying, Fax. Modify-Reproduce Capturing an image for inclusion in a document or display, often with modification, scaling, cropping, etc. Parameters may not be known and area to be scanned may be inconsistent, fidelity important. Extract-Analysis Processing an image for analysis or interpretation, such as OCR or feature analysis. Parameters and area probably well defined, fidelity not too important for extraction. Analysis required very high fidelity. 10
Character and mark recognition devices Scanners that recognize special characters & marks Magnetic ink character recognition (MICR) Optical-character recognition (OCR) Optical-mark recognition (OMR) 11
Scanners read and interpret information on printed matter The information is converted to a format for storage 12
Grades test Checks survey The sense marks are compared on the test by the scanner Corrections are calculated 13
Scanners capture and digitize printed images. There are several types of scanners: Flatbed scanners Handheld scanners Sheet-fed scanners 14
Item to be scanned is to be pulled into a stationary scanning mechanism Smaller and less expensive than flatbed scanner 15
Item to be scanned rotates around stationary scanning mechanism Very large and expensive Used in the publishing industry. 16