Editing Image scanner (section)

== Types ==
=== Flatbed ===<!-- [[Flatbed scanner]] redirects here -->
[[File:HP-Scanjet-IIC 05.jpg|thumb|A flatbed scanner ([[HP ScanJet|HP ScanJet IIC]]) with its lid closed]]
A flatbed scanner is a type of scanner that provides a glass bed ([[platen]]) on which the object to be scanned lies motionless. The scanning element moves vertically from under the glass, scanning either the entirety of the platen or a predetermined portion. The driver software for most flatbed scanners allows users to prescan their documents—in essence, to take a quick, low-resolution pass at a document in order to judge what area of the document should be scanned (if not the entirety of it), before scanning it at a higher resolution. Some flatbed scanners incorporate sheet-feeding mechanisms called [[automatic document feeder]]s (ADFs) that use the same scanning element as the flatbed portion.<ref>{{cite web | date=n.d. | url=https://www.pcmag.com/encyclopedia/term/flatbed-scanner | title=Definition of flatbed scanner | work=PC Magazine | publisher=Ziff-Davis | archiveurl=https://web.archive.org/web/20231209215942/https://www.pcmag.com/encyclopedia/term/flatbed-scanner | archivedate=December 9, 2023}}</ref><ref>{{cite book | last=Gookin | first=Dan | author-link=Dan Gookin | date=2013 | url=https://books.google.com/books?id=-H_6Ml7nnQAC | title=PCs for Dummies | publisher=Wiley | page=304 | edition=12th, ebook | isbn=9781118232613 | via=Google Books}}</ref>

This type of scanner is sometimes called a ''reflective scanner'', because it works by shining white light onto the object to be scanned and reading the intensity and color of light that is reflected from it, usually a line at a time. They are designed for scanning prints or other flat, opaque materials, but some have available transparency adapters, which—for a number of reasons—in most cases, are not very well suited to scanning film.<ref name="basics">{{cite web | url=http://www.dl-c.com/basics.pdf | title=Digital Image Basics | last=Sachs | first=J. | publisher=Digital Light & Color | date=February 1, 2001 | access-date=November 19, 2015 | url-status=dead | archive-url=https://web.archive.org/web/20151120202325/http://www.dl-c.com/basics.pdf | archive-date=November 20, 2015}}</ref>

=== Sheetfed{{anchor|Roller scanner}} ===
[[File:ScanSnap iX500 029 (8703118513).jpg|thumb|An [[automatic document feeder]] ([[Fujitsu]] ScanSnap iX500)]]
A sheetfed scanner, also known as a document feeder,<ref>{{cite web | date=n.d. | url=https://www.pcmag.com/encyclopedia/term/sheet-feeder | title=Definition of sheet feeder | work=PC Magazine | publisher=Ziff-Davis | archiveurl=https://web.archive.org/web/20240418115952/https://www.pcmag.com/encyclopedia/term/sheet-feeder | archivedate=April 18, 2024}}</ref> is a type of scanner that uses motor-driven rollers to move one single sheet of paper at a time past a stationary scanning element (two scanning elements, in the case of scanners with duplex functionality).<ref name=sheetfeddef /><ref name=brotherds /> Unlike flatbed scanners, sheetfed scanners are not equipped to scan [[Bookbinding|bound]] material such as books or magazines, nor are they suitable for any material thicker than plain printer paper.<ref name=sheetfeddef>{{cite web | date=n.d. | url=https://www.pcmag.com/encyclopedia/term/sheet-fed-scanner | title=Definition of sheet-fed scanner | work=PC Magazine | publisher=Ziff-Davis | archiveurl=https://web.archive.org/web/20230925002449/https://www.pcmag.com/encyclopedia/term/sheet-fed-scanner | archivedate=September 25, 2023}}</ref><ref>{{cite book | last=Mueller | first=Scott | date=1999 | url=https://books.google.com/books?id=6M1XAAAAYAAJ | title=Upgrading and Repairing PCs | publisher=Que | page=1194 | isbn=9780789719034 | via=Google Books | edition=11th}}</ref> Some sheetfed scanners, called automatic document feeders (ADFs), are capable of scanning several sheets in one session,<ref>{{Cite web | url=https://www.yuenx.com/2021/review-epson-workforce-es-580w-wifi-color-duplex-desktop-scanner-with-adf/ | title=Review: Epson Workforce ES-580W WiFi Color Duplex Desktop Scanner with ADF | first=Michael | last=Yuen | work=Yuenx | date=April 12, 2021}}</ref><ref>{{Cite magazine | url=https://www.wired.com/2008/01/review-fujitsu/ | title=Review: Fujitsu ScanSnap S300 Scans And Delivers | first=Daniel | last=Dumas | magazine=Wired | publisher=Condé Nast | archiveurl=https://web.archive.org/web/20151120070057/https://www.wired.com/2008/01/review-fujitsu/ | archivedate=November 20, 2015 | date=January 24, 2008}}</ref> although others only accept one page at a time.<ref name=brotherds>{{cite web | url=https://www.pcmag.com/reviews/brother-dsmobile-ds-940dw | title=Brother DSmobile DS-940DW Review | work=PCMag | publisher=Ziff-Davis | last=Harrel | first=William | date=March 2, 2020 | archiveurl=https://web.archive.org/web/20200305052834/https://www.pcmag.com/reviews/brother-dsmobile-ds-940dw | archivedate=March 5, 2020}}</ref> Some sheetfed scanners are [[#Portable|portable]], powered by batteries, and have their own storage, eventually transferring stored scans to a computer.<ref name=brotherds />

=== Handheld{{anchor|Hand}} ===
[[File:Logitech ScanMan Color-P4191193-white.jpg|thumb|A handheld scanner ([[Logitech]] ScanMan Color)]]
A handheld scanner is a type of scanner that must be manually dragged or gilded by hand across the surface of the object to be scanned. Scanning documents in this manner requires a steady hand, as an uneven scanning rate produces distorted images.<ref>{{cite web | date=n.d. | url=https://www.pcmag.com/encyclopedia/term/handheld-scanner | title=Definition of handheld scanner | work=PC Magazine | publisher=Ziff-Davis | archiveurl=https://web.archive.org/web/20240303064613/https://www.pcmag.com/encyclopedia/term/handheld-scanner | archivedate=March 3, 2024}}</ref> Some handheld scanners have an indicator light on the scanner for this purpose, actuating if the user is moving the scanner too fast.<ref>{{cite book | last=Baeseler | first=Frank | author2=Bruce Bovill | date=1993 | url=https://books.google.com/books?id=8qHbAAAAMAAJ | title=Scanning and Image Processing for the PC | publisher=McGraw-Hill | page=47 | isbn=9780077078195 | via=Google Books}}</ref> They typically have at least one button that starts the scan when pressed; it is held by the user for the duration of the scan. Some other handheld scanners have switches to set the [[optical resolution]], as well as a roller, which generates a clock pulse for synchronization with the computer.<ref name=gruman>{{cite journal | last=Gruman | first=Galen | date=April 29, 1991 | url=https://books.google.com/books?id=y1AEAAAAMBAJ&pg=PT53 | title=Scanning on a Budget | journal=InfoWorld | publisher=IDG Publications | volume=13 | issue=17 | pages=51–62 | via=Google Books}}</ref><ref>{{cite book | last=Busch | first=David D. | author-link=David D. Busch | date=1991 | url=https://books.google.com/books?id=SyYzAAAAMAAJ | title=The Complete Scanner Toolkit for the IBM PC | publisher=Business One Irwin | page=97 | isbn=9781556234798 | via=Google Books}}</ref> Older hand scanners were [[monochrome]], and produced light from an array of green [[Light-emitting diode|LED]]s to illuminate the image; later ones scan in monochrome or color, as desired.<ref>{{cite journal | last=Pastrick | first=Greg | date=November 24, 1992 | url=https://books.google.com/books?id=RJBJPJvct40C&pg=PA40 | title=Logitech's New Hand Scanner Does 24-Bit Color | journal=PC Magazine | publisher=Ziff-Davis | volume=11 | issue=20 | page=40 | via=Google Books}}</ref> A hand scanner may also have a small window through which the document being scanned could be viewed. As hand scanners are much narrower than most normal document or book sizes, software (or the end user) needed to combine several narrow "strips" of scanned documents to produce the finished article.<ref name=gruman /><ref>{{cite journal | last=Falkner | first=Mike | date=November 29, 1988 | url=https://books.google.com/books?id=TJuFGeKsMJ0C&pg=PA295 | title=Hand Scanners Inch Forward | journal=PC Magazine | publisher=Ziff-Davis | volume=7 | issue=20 | pages=277–308 | via=Google Books}}</ref>

Inexpensive, [[#Portable|portable]], battery-powered or USB-powered wand scanners and pen scanners, typically capable of scanning an area as wide as a normal letter and much longer, remain available {{As of|2024|lc=on}}.<ref name=best /><ref>{{Cite web | url=https://me.pcmag.com/en/accessories/2781/irispen-executive-7 | title=IRISPen Executive 7 | date=July 26, 2015 | work=PCMag Middle East | publisher=Ziff-Davis | last=Fernando | first=Chris | archiveurl=https://web.archive.org/web/20221003124123/https://me.pcmag.com/en/accessories/2781/irispen-executive-7 | archivedate=October 3, 2022}}</ref><ref>{{Cite web | last=Calderone | first=Nicholas | url=https://macsources.com/irispen-air-7-smart-wireless-pen-scanner-review/ | title=IRISPen Air 7 Smart Wireless Pen Scanner Review | date=April 25, 2018 | work=MacSources | archiveurl=https://web.archive.org/web/20190525214346/https://macsources.com/irispen-air-7-smart-wireless-pen-scanner-review/ | archivedate=May 25, 2019}}</ref> Some [[Computer mouse|computer mice]] can also scan documents.<ref>{{cite web | url=https://www.pcmag.com/reviews/iriscan-mouse-executive-2 | title=IRIScan Mouse Executive 2 Review | work=PCMag | publisher=Ziff-Davis | last=Harrel | first=William | date=February 7, 2020 | archiveurl=https://web.archive.org/web/20200215191555/https://www.pcmag.com/reviews/iriscan-mouse-executive-2 | archivedate=February 15, 2020}}</ref>

=== Drum ===
{{Main|Drum scanner}}
[[File:1977 Januar Wuppertal 027.jpg|thumb|A [[drum scanner]] ([[Linotype-Hell|Hell]] Chromagraph DC 300) being operated]]
A [[drum scanner]] is a type of scanner that uses a clear, motor-driven rotating cylinder (drum) onto which a print, a film negative, a transparency, or any other flat object is taped or otherwise secured. A beam of light either projects past, or reflects off, the material to be scanned onto a series of mirrors, which focus the beam onto the drum scanner's photomultiplier tube (PMT). After one revolution, the beam of light moves down a single step. When scanning transparent media, such as negatives, a light beam is directed from within the cylinder onto the media; when scanning opaque items, a light beam from above is reflected off the surface of the media. When only one PMT is present, three passes of the image are required for a full-color RGB scan. When three PMTs are present, only a single pass is required.<ref name=drumdef>{{cite web | date=n.d. | url=https://www.pcmag.com/encyclopedia/term/drum-scanner | title=Definition of drum scanner | work=PC Magazine | publisher=Ziff-Davis | archiveurl=https://web.archive.org/web/20230930230924/https://www.pcmag.com/encyclopedia/term/drum-scanner | archivedate=September 30, 2023}}</ref>

The photomultiplier tubes of drum scanners offer superior dynamic range to that of CCD sensors. For this reason, drum scanners can extract more detail from very dark shadow areas of a transparency than flatbed scanners using CCD sensors. The smaller dynamic range of the CCD sensors (versus photomultiplier tubes) can lead to loss of shadow detail, especially when scanning very dense transparency film.<ref>{{cite web | url=http://www.dl-c.com/Temp/downloads/Whitepapers/Scan.pdf | title=Scanners and How to Use Them | last=Sachs | first=J. | publisher=Digital Light & Color | date=February 1, 2001 | access-date=November 8, 2015}}</ref> Drum scanners are also able to resolve true detail in excess of 10000 dpi, producing higher-resolution scans than any CCD scanner.<ref name=drumdef />

=== Overhead{{anchor|Book scanners}}{{anchor|Document camera scanner}}{{anchor|Planetary scanner}} ===
{{See also|Book scanning|Document camera|Planetary scanner}}
[[File:ET Series Book Scanner.png|thumb|An overhead [[book scanner]] (CZUR ET Series) with lasers for calibration]]
An overhead scanner is a type of scanner that places the scanning element in a housing on top of a vertical post, hovering above the document or object to be scanned, which lies stationary on an open-air bed. [[Chinon Industries]] patented a specific type of overhead scanner, which uses a rotating mirror to reflect the contents of the bed onto a linear CCD, in 1987. Although very flexible—allowing users to scan not only two-dimensional prints and documents but any 3D object, of any size—the Chinon design required the user to provide uniform illumination of the object to be scanned and was more cumbersome to set up.<ref>{{cite journal | last=Staff writer | date=December 1, 1987 | url=https://link.gale.com/apps/doc/A6117970/GPS?u=wikipedia | title=Chinon's PC-, Mac-Compatible Overhead Scanner Doesn't Require Special Lighting | journal=PC Week | publisher=Ziff-Davis | volume=4 | issue=48 | page=35 | via=Gale}}</ref><ref>{{cite journal | last=Linzmayer | first=Owen W. | date=September 1990 | url=https://link.gale.com/apps/doc/A8679416/GPS?u=wikipedia | title=Desktop Scanners | journal=MacUser | publisher=IDG Communications | volume=6 | issue=9 | pages=136 | via=Gale}}</ref><ref>{{cite journal | last=Karney | first=James | date=April 14, 1992 | url=https://books.google.com/books?id=AoKUhNoOys4C&pg=PP273 | title=Marching to a Different Drummer: The Chinon DS-3000 Color Scanner | journal=PC Magazine | publisher=Ziff-Davis | volume=11 | issue=7 | page=251 | via=Google Books}}</ref>

A more modern type of overhead scanner is a [[document camera]] (also known as a video scanner), which uses a [[digital camera]] to capture a document all at once. Most document cameras output live video of the document and are usually reserved for displaying documents to a live audience, but they may also be used as replacements for image scanners, capturing a single frame of the output as an image file. Document cameras may even use the same [[#Applications programming interface|API]]s as scanners when connected to computers.<ref>{{cite web | last=Juniper | first=Adam | date=April 11, 2024 | url=https://www.digitalcameraworld.com/buying-guides/best-document-camera | title=Best document camera in 2024: which visualizer is the right one for you? | work=Digital Camera World | publisher=Future Publishing}}</ref> A [[planetary scanner]] is a type of very-high-resolution document camera used for capturing certain fragile documents.<ref>{{cite book | last=Monson | first=Jane D. | date=2017 | url=https://books.google.com/books?id=MXs4DwAAQBAJ | title=Getting Started with Digital Collections: Scaling to Fit Your Organization | isbn=9780838915431 | publisher=American Library Association | via=Google Books}}</ref> A [[Book scanning|book scanner]] is another kind of document camera, pairing a digital camera with a scanning area defined by a mat to assist in scanning books. Some more advanced models of book scanners project a laser onto the page for calibration and software skew correction.<ref>{{cite web | url=https://www.pcmag.com/reviews/czur-shine-ultra-pro | title=CZUR Shine Ultra Pro Review | work=PCMag | publisher=Ziff-Davis | last=Harrel | first=William | date=May 3, 2022 | archiveurl=https://web.archive.org/web/20220504003440/https://www.pcmag.com/reviews/czur-shine-ultra-pro | archivedate=May 4, 2022}}</ref><ref>{{Cite web | url=https://www.zdnet.com/home-and-office/smart-office/fujitsu-scansnap-sv600-review/ | title=Do you dream of digitizing your entire book collection? This book scanner can help | website=ZDNET | publisher=Ziff-Davis | last=Gewirtz | first=David | date=October 3, 2022 | archiveurl=https://web.archive.org/web/20221003171500/https://www.zdnet.com/home-and-office/smart-office/fujitsu-scansnap-sv600-review/ | archivedate=October 3, 2022}}</ref>

=== Film ===
{{Main article|Film scanner}}
[[File:Reflecta DigitDia 6000 Slide Scanner (1).jpg|thumb|A [[film scanner]] (Reflecta DigitDia 6000) designed for scanning [[Slide projector|slides]]]]
A [[film scanner]], also known as a slide scanner or a transparency scanner, is a type of specialized flatbed scanner specifically for scanning film negatives and [[Slide projector|slides]]. A typical film scanner works by passing a narrowly focused beam of light through the film and reading the intensity and color of the light that emerges.<ref name="basics"/> The lowest-cost dedicated film scanners can be had for less than $50, and they might be sufficient for modest needs. From there they inch up in staggered levels of quality and advanced features upward of five figures.<ref>{{cite web | url=https://www.bhphotovideo.com/explora/photography/buying-guide/film-scanners | title=Film Scanners: A Buying Guide | last=Weitz | first=A. | publisher=B&H Photo Video | date=November 6, 2015 | access-date=November 19, 2015}}</ref>

=== Portable ===
[[File:Card Scanner.svg|thumb|An illustration of a portable business card scanner]]
Image scanners are usually used in conjunction with a [[computer]] which controls the scanner and stores scans. Small portable scanners, either [[#Sheetfed|sheetfed]] or [[#Handheld|handheld]] and operated by batteries and with storage capability, are available for use away from a computer; stored scans can be transferred later.<ref name=best>{{cite web | last=Brant | first=Tom | author2=John Burek | date=July 1, 2024 | url=https://www.pcmag.com/picks/the-best-portable-scanners | title=The Best Portable Scanners for 2024 | work=PCMag | publisher=Ziff-Davis | archiveurl=https://web.archive.org/web/20240804180551/https://www.pcmag.com/picks/the-best-portable-scanners | archivedate=August 4, 2024}}</ref> Many can scan both small documents such as [[business card]]s and till [[receipt]]s, as well as letter-sized documents.<ref name=best /><ref>{{cite book | last=Baldridge | first=Aimee | date=2009 | url=https://books.google.com/books?id=Ewvuqm-1YboC | title=Organize Your Digital Life: How to Store Your Photographs, Music, Videos, and Personal Documents in a Digital World | publisher=National Geographic | page=163 | isbn=9781426203343 | via=Google Books}}</ref>

=== Software scanners{{anchor|Smartphone scanner app}} ===
The higher-resolution cameras fitted to some [[smartphone]]s can produce reasonable quality document scans by taking a photograph with the phone's camera and post-processing it with a scanning app, a range of which are available for most phone [[operating system]]s, to whiten the background of a page, correct perspective distortion so that the shape of a rectangular document is corrected, convert to black-and-white, etc. Many such apps can scan multiple-page documents with successive camera exposures and output them either as a single file or multiple-page files. Some smartphone scanning apps can save documents directly to online storage locations, such as [[Dropbox (service)|Dropbox]] and [[Evernote]], send via email, or fax documents via email-to-fax gateways.<ref name=mit />

Smartphone scanner apps can be broadly divided into three categories:
# Document scanning apps primarily designed to handle documents and output PDF, and sometimes JPEG, files
# Photo scanning apps that output JPEG files, and have editing functions useful for photo rather than document editing;
# Barcode-like [[QR code]] scanning apps that then search the internet for information associated with the code.<ref name=mit>{{cite web | url=https://www.technologyreview.com/s/425907/scan-anything-and-let-your-phone-do-the-rest/ | title=Scan Anything and Let Your Phone Do the Rest | work=MIT Technology Review | publisher=Massachusetts Institute of Technology | last=Muller | first=Ian E.}}</ref>