Editing Digital image (section)

==Raster==
{{main|Raster image}}
Raster images have a finite set of [[Digital data|digital]] values, called ''picture elements'' or [[pixel]]s. The digital image contains a fixed number of rows and columns of pixels. Pixels are the smallest individual element in an image, holding quantized values that represent the brightness of a given color at any specific point.

Typically, the pixels are stored in computer memory as a [[raster graphics|raster image]] or raster map, a two-dimensional array of small integers. These values are often transmitted or stored in a [[image compression|compressed]] form.

Raster images can be [[digital imaging|created]] by a variety of input devices and techniques, such as [[digital camera]]s, [[Image scanner|scanner]]s, coordinate-measuring machines, seismographic profiling, airborne radar, and more. They can also be synthesized from arbitrary non-image data, such as mathematical functions or three-dimensional geometric models; the latter being a major sub-area of [[computer graphics]]. The field of [[digital image processing]] is the study of algorithms for their transformation.

===Raster file formats===
{{main|Raster file format}}
Most users come into contact with raster images through digital cameras, which use any of several [[image file formats]].

Some [[digital camera]]s give access to almost all the data captured by the camera, using a [[raw image format]]. ''The Universal Photographic Imaging Guidelines (UPDIG)'' suggests these formats be used when possible since raw files produce the best quality images. These file formats allow the photographer and the processing agent the greatest level of control and accuracy for output. Their use is inhibited by the prevalence of proprietary information ([[trade secrets]]) for some camera makers, but there have been initiatives such as [[OpenRAW]] to influence manufacturers to release these records publicly. An alternative may be [[Digital Negative (file format)|Digital Negative (DNG)]], a proprietary Adobe product described as "the public, archival format for digital camera raw data".<ref>[https://www.adobe.com/products/dng/index.html ''Digital Negative (DNG) Specification''] {{Webarchive|url=https://web.archive.org/web/20110420165322/https://www.adobe.com/products/dng/index.html |date=2011-04-20 }}. San Jose: Adobe, 2005. Vers. 1.1.0.0. p. 9. Accessed on October 10, 2007.</ref> Although this format is not yet universally accepted, support for the product is growing, and increasingly professional archivists and conservationists, working for respectable organizations, variously suggest or recommend DNG for archival purposes.<ref name="UPDIG">universal photographic digital imaging guidelines (UPDIG): [https://www.updig.org/guidelines/ph_file_formats.html File formats - the raw file issue] {{Webarchive|url=https://web.archive.org/web/20111020052554/https://www.updig.org/guidelines/ph_file_formats.html |date=2011-10-20 }}</ref><ref name="ADSDA">Archaeology Data Service / Digital Antiquity: [https://guides.archaeologydataservice.ac.uk/g2gp/RasterImg_3 Guides to Good Practice - Section 3 Archiving Raster Images - File Formats] {{Webarchive|url=https://web.archive.org/web/20111214082154/https://guides.archaeologydataservice.ac.uk/g2gp/RasterImg_3 |date=2011-12-14 }}</ref><ref name="UofC">University of Connecticut: [https://digitalcommons.uconn.edu/libr_pubs/23/ "Raw as Archival Still Image Format: A Consideration" by Michael J. Bennett and F. Barry Wheeler] {{Webarchive|url=https://web.archive.org/web/20110914165511/https://digitalcommons.uconn.edu/libr_pubs/23/ |date=2011-09-14 }}</ref><ref name="IUCPSR">Inter-University Consortium for Political and Social Research: [https://www.icpsr.umich.edu/dpm/dpm-eng/oldmedia/obsolescence1.html Obsolescence - File Formats and Software] {{Webarchive|url=https://web.archive.org/web/20111102185230/https://www.icpsr.umich.edu/dpm/dpm-eng/oldmedia/obsolescence1.html |date=2011-11-02 }}</ref><ref name="JISC">JISC Digital Media - Still Images: [https://www.jiscdigitalmedia.ac.uk/stillimages/advice/choosing-a-file-format-for-digital-still-images/#fo3 Choosing a File Format for Digital Still Images - File formats for master archive] {{Webarchive|url=https://web.archive.org/web/20111116002515/https://www.jiscdigitalmedia.ac.uk/stillimages/advice/choosing-a-file-format-for-digital-still-images#fo3 |date=2011-11-16 }}</ref><ref name="JPGM">The J. Paul Getty Museum - Department of Photographs: [https://www.yale.edu/digitalcoffee/downloads/speedtheplowmcn2009handout.pdf Rapid Capture Backlog Project - Presentation] {{Webarchive|url=https://web.archive.org/web/20120610105143/https://www.yale.edu/digitalcoffee/downloads/speedtheplowmcn2009handout.pdf |date=2012-06-10 }}</ref><ref name="786 newsa">most important image on the internet - Electronic Media Group: [https://cool.conservation-us.org/coolaic/sg/emg/library/pdf/vitale/2007-07-vitale-digital_image_file_formats.pdf Digital Image File Formats] {{Webarchive|url=https://web.archive.org/web/20101214052741/https://cool.conservation-us.org/coolaic/sg/emg/library/pdf/vitale/2007-07-vitale-digital_image_file_formats.pdf |date=2010-12-14 }}</ref><ref name="AABC">Archives Association of British Columbia: [https://786news.com/top-15-most-important-image-on-the-internet-that-people-often-to-search-for/ Acquisition and Preservation Strategies (Rosaleen Hill)]</ref>