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1、2009-11-14Aspectratio(image)-Wikipedia,…Aspectratio(image)FromWikipedia,thefreeencyclopediaTheaspectratioofanimageisitswidthdividedbyFivecommonaspectratiositsheight.Aspectratiosaremathematicallyexpressedasx:y(pronounced"x-to-y")andx×y(pronounced"x-by-y").Themostcommonaspectratiosusedto
2、dayinthepresentationoffilmsinmovietheatersare1.85:1and2.39:1.[1]Twocommonvideographicaspectratiosare4:3(1.33:1),universalforstandard-definitionvideoformats,and16:9(1.78:1),universaltohigh-definitiontelevisionandEuropeandigitaltelevision.Othercinemaandvideoaspectratiosexist,butareusedin
3、frequently.Instillcameraphotography,themostcommonaspectratiosare4:3,3:2,andmorerecentlybeingfoundinconsumercameras,previouslyonlycommonlyseeninprofessionalcameras,16:9[2].Otheraspectratios,suchas5:4,6:7,and1:1(squareformat),areusedinphotographyaswell.IntelevisionandonDVDs,convertingfor
4、matsofunequalratiosisdonebycroppingtheoriginalimagetothereceivingformat'saspectratio(zooming),byaddinghorizontalmattes(letterboxing)orverticalmattes(pillarboxing)toretaintheoriginalformat'saspectratio,orbydistortingtheimagetofillthereceivingformat'sratio.Cinematographicaspectratiosareu
5、suallydenotedasadecimalfractionwidthtounitheight,whilevideographicaspectratiosareusuallydenotedbyratiosofwholenumbers.Contents1Practicallimitations2Cinematerminology2.1Moviecamerasystems3Currentvideostandards3.14:3standard3.216:9standard3.2.1Why16:9waschosenbytheSMPTE3.2.216:9inEurope4
6、Obtainingheight,widthandareaofthescreen5Visualcomparisons6Previousandpresentlyusedaspectratios7Aspectratioreleases…wikipedia.org/…/Aspect_ratio_(…1/14PDF文件使用"pdfFactoryPro"试用版本创建www.fineprint.cn2009-11-14Aspectratio(image)-Wikipedia,…7.1Originalaspectratio(OAR)7.2Modifiedaspectratio(MA
7、R)8Problemsinfilmandtelevision9Stillphotography10Seealso11References12ExternallinksPracticallimitationsInmotionpictureformats,thephysicalsizeofthefilmareabetweenthesprocketperforationsdeterminestheimage'ssize.Theuniversalstandard(establishedbyWilliamDicksonandThomasEdisonin1892)isafr
