Editing Multi-exposure HDR capture (section)

=== Late 20th century ===
Georges Cornuéjols and licensees of his patents (Brdi, Hymatom) introduced the principle of HDR video image, in 1986, by interposing a matricial LCD screen in front of the camera's image sensor,<ref>{{Cite web |url= https://worldwide.espacenet.com/publicationDetails/biblio?II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=19910924&CC=US&NR=5051770A&KC=A# |title=Image processing device for controlling the transfer function of an optical system |work=Worldwide.Espacenet.com |publisher=[[Espacenet]] }}</ref> increasing the sensors dynamic by five stops.

The concept of neighborhood tone mapping was applied to video cameras in 1988 by a group from the [[Technion]] in Israel, led by Oliver Hilsenrath and Yehoshua Y. Zeevi. Technion researchers filed for a patent on this concept in 1991,<ref>{{cite patent |country=US |status=patent |number=5144442 |title=Wide dynamic range camera |pubdate=1992-09-01 |fdate=1991-11-21 |inventor1-last=Ginosar |inventor1-first=Ran |inventor2-last=Hilsenrath |inventor2-first=Oliver |inventor3-last=Zeevi |inventor3-first=Yehoshua Y.}}</ref> and several related patents in 1992 and 1993.<ref name="Technion">{{cite web |last1=Ginosar |first1=Ran |last2=Zinaty |first2=Ofra |last3=Sorek |first3=Noam |last4=Genossar |first4=Tamar |last5=Zeevi |first5=Yehoshua Y. |last6=Kligler |first6=Daniel J. |last7=Hilsenrath |first7=Oliver |title=Adaptive Sensitivity |url= http://visl.technion.ac.il/research/isight/AS/ |date=1993 |work=VISL.Technion.ac.il |publisher=Vision and Image Sciences Laboratory, [[Technion]], [[Israel Institute of Technology]] |access-date=January 27, 2019 |archive-url= https://web.archive.org/web/20140907142738/http://visl.technion.ac.il/research/isight/AS/ |archive-date=September 7, 2014 |url-status=dead}}</ref>

In February and April 1990, Georges Cornuéjols introduced the first real-time HDR camera that combined two images captured successively by a sensor<ref name="espacenet1">{{Cite web |url= https://worldwide.espacenet.com/publicationDetails/biblio?II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=19970610&CC=US&NR=5638119A&KC=A# |title=Device for increasing the dynamic range of a camera |work=Worldwide.Espacenet.com |publisher=Espacenet }}</ref> or simultaneously<ref>{{Cite web |url= https://worldwide.espacenet.com/publicationDetails/biblio?II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=19970610&CC=US&NR=5638119A&KC=A# |title=Camera with very wide dynamic range |work=Worldwide.Espacenet.com |publisher=Espacenet }}</ref> by two sensors of the camera. This process is known as [[bracketing]] used for a video stream.

In 1991, the first commercial video camera was introduced that performed real-time capturing of multiple images with different exposures, and producing an HDR video image, by Hymatom, licensee of Georges Cornuéjols.

Also in 1991, Georges Cornuéjols introduced the HDR+ image principle by non-linear accumulation of images to increase the sensitivity of the camera:<ref name="espacenet1" /> for low-light environments, several successive images are accumulated, thus increasing the [[Signal-to-noise ratio (imaging)|signal-to-noise ratio]].

In 1993, another commercial medical camera  producing an HDR video image, by the Technion.<ref name="Technion" />

Modern HDR imaging uses a completely different approach, based on making a high-dynamic-range luminance or light map using only global image operations (across the entire image), and then [[tone mapping]] the result. Global HDR was first introduced in 1993<ref name="mann1993">{{cite conference |title=Compositing Multiple Pictures of the Same Scene |first=Steve |last=Mann |publisher=Society for Imaging Science and Technology |isbn=0892081716 |conference=46th Annual Conference |location=Cambridge, Massachusetts |date=May 9–14, 1993}}</ref> resulting in a mathematical theory of differently exposed pictures of the same subject matter that was published in 1995 by [[Steve Mann (inventor)|Steve Mann]] and [[Rosalind Picard]].<ref name="mann1995">{{cite web |url= http://wearcam.org/is_t95_myversion.pdf |title=On Being 'Undigital' with Digital Cameras: Extending Dynamic Range by Combining Differently Exposed Pictures |first1=S. |last1=Mann |first2=R. W. |last2=Picard}}</ref>

On October 28, 1998, Ben Sarao created one of the first nighttime HDR+G (high dynamic range + graphic) image of [[STS-95]] on the launch pad at [[NASA]]'s [[Kennedy Space Center]]. It consisted of four film images of the [[Space Shuttle|space shuttle]] at night that were [[Digital compositing|digitally composited]] with additional digital graphic elements. The image was first exhibited at [[NASA Headquarters]] Great Hall, Washington DC, in 1999 and then published in ''Hasselblad Forum''.<ref>{{cite book |work=Hasselblad Forum |date=1999 |volume=35 |issue=3 |issn=0282-5449 |title=Ben Sarao, Trenton, NJ |first=Ben M. |last=Sarao |editor-first=S. |editor-last=Gunnarsson}}<!--Someone put a 1993 date on that, but that is not possible for a 1998 image.--></ref>

The advent of consumer digital cameras produced a new demand for HDR imaging to improve the light response of digital camera sensors, which had a much smaller dynamic range than film. [[Steve Mann (inventor)|Steve Mann]] developed and patented the global-HDR method for producing digital images having extended dynamic range at the [[MIT Media Lab]].<ref name="MannPatent">{{cite patent |country=US |number=5828793 |status=application |title=Method and apparatus for producing digital images having extended dynamic ranges |pubdate=1998-10-27 |fdate=1996-05-06 |inventor-first=Steve |inventor-last=Mann |inventor-link=Steve Mann (inventor)}}</ref> Mann's method involved a two-step procedure: First, generate one floating point image array by global-only image operations (operations that affect all pixels identically, without regard to their local neighborhoods). Second, convert this image array, using local neighborhood processing (tone-remapping, etc.), into an HDR image. The image array generated by the first step of Mann's process is called a ''lightspace image'', ''lightspace picture'', or ''radiance map''. Another benefit of global-HDR imaging is that it provides access to the intermediate light or radiance map, which has been used for [[computer vision]], and other [[Digital image processing|image processing]] operations.<ref name="MannPatent" />