Editing Digital camera (section)

=== Line-scan camera systems ===
{{main|line-scan camera}}
{{Unreferenced section|date=December 2019}}
[[File:Strip photo of San Francisco Cable Car 10.jpg|thumb|A San Francisco cable car, imaged using an [https://www.alkeria.com/ Alkeria] [https://www.alkeria.com/products/necta-series Necta] N4K2-7C line scan camera with a shutter speed of 250 microseconds, or 4000 frames per second.]]
A line-scan camera traditionally has a single row of [[pixel sensor]]s, instead of a matrix of them. The lines are continuously fed to a computer that joins them to each other and makes an image.<ref>{{cite book|url=https://books.google.com/books?id=tppFDwAAQBAJ|title=Machine Vision Algorithms and Applications|author=Steger|first=Carsten|author2=Markus Ulrich|author3=Christian Wiedemann|date=2018|publisher=[[Wiley-VCH]]|edition=2nd|isbn=978-3-527-41365-2|location=Weinheim|page=41|access-date=2021-04-19|archive-date=2023-03-15|archive-url=https://web.archive.org/web/20230315180825/https://books.google.com/books?id=tppFDwAAQBAJ|url-status=live}}</ref><ref>{{Cite journal | title = A Camera Model for Line-Scan Cameras with Telecentric Lenses | author = Carsten Steger, Markus Ulrich | journal = International Journal of Computer Vision | volume = 129 | pages = 80–99 | date = 2021 | doi = 10.1007/s11263-020-01358-3 | doi-access = free }}</ref> This is most commonly done by connecting the camera output to a [[frame grabber]] which resides in a [[PCI slot]] of an industrial computer. The frame grabber acts to buffer the image and sometimes provide some processing before delivering to the computer software for processing. Industrial processes often require height and width measurements performed by digital line-scan systems.<ref>{{cite book |last1=Boyes |first1=Walt |title=Instrumentation reference book. |date=2 December 2002 |publisher=Butterworth-Heinemann-Elsevier Science |isbn=0-08-047853-0 |page=891 |edition=3rd. |url=https://books.google.com/books?id=sarHIbCVOUAC |access-date=31 January 2020}}</ref>

Multiple rows of sensors may be used to make colored images, or to increase sensitivity by TDI ([[time delay and integration]]).

Many industrial applications require a wide field of view. Traditionally maintaining consistent light over large [[Plane (mathematics)|2D]] areas is quite difficult. With a line scan camera all that is necessary is to provide even illumination across the "line" currently being viewed by the camera. This makes sharp pictures of objects that pass the camera at high speed.

Such cameras are also commonly used to make [[photo finish]]es, to determine the winner when multiple competitors cross the finishing line at nearly the same time. They can also be used as industrial instruments for analyzing fast processes.

Line-scan cameras are also extensively used in imaging from [[satellite]]s (see [[push broom scanner]]). In this case the row of sensors is perpendicular to the direction of satellite motion. Line-scan cameras are widely used in scanners. In this case, the camera moves horizontally.

{{further|Rotating line camera|Strip photography}}