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1、DigitalImageFundmentWhatisImage?ImageImageofobjectMathematicFunctionPicturePhoticImageContinueFunctionDiscreteFunctionInvisibleImage图像与影像DigitalImage?Sincecomputersstoredataandunderstanddatainanumericalform,wecansaythatanimageisanumericalrepresentationofa“picture”–asetofnumbersinterpretedbythecomput
2、erwhichcreatesavisualrepresentationthatisunderstoodbyhumans.25525519914397187321234232211244198179123941953243521332112532172346818597131227111426Graphics?TypeofImageColorScaleNumberFileFormatDimensionbinarygraycolorColorofImageColorSystem(model)RGB模型HIS模型YIQ,YUV,HSV,CMYK,HSL…TrueColorandPseudocolor
3、24truecolorand32truecolorPseudoclor:Thecolorwegivetoaimagetoshowtheinformation.inwhichdifferentcolorlevelrepresentdifferentdata.WhatisgrayGrayScalepixelvaluesrepresentalevelofgraynessorbrightness,rangingfromcompletelyblacktocompletelywhite.Inan8-bitGrayScaleimage,apixelwithavalueof0iscompletelyblack
4、,andapixelwithavalueof255iscompletelywhite.Avalueof127representsagraycolorexactlyhalfwaybetweenblackandwhite(medium-gray),andapixelvalueof64hasagraycolorhalfwaybetweenmedium-grayandblack.ScaleNumberGreylevelWeusegreyleveltorepresentbrightnessinformationinapicture.Ifonepictureonlyhave2purecolors:whit
5、eandblack,itsinformationisverylimited.Toshowmoreinformation,wecanadoptgreyImage,thatUsuallyis6greyscale(26,64level)or8greyscale(28,256level).256shadesofgray4grayscale6grayscale8grayscaleAlthoughGrayScaleimageswithbitdepthsof2,4,6,12,16and32exist,8BitGrayScaleimagesarethemostcommon.Thisisfortworeason
6、s:1)its1-byte-per-pixelsizemakesiteasytomanipulatewithacomputer,and2)itcanfaithfullyrepresentanygrayscaleimagebecauseitprovides256distinctlevelsofgray(thehumaneyecandistinguishlessthan200graylevels).FileFormatBMP:微软Windows设置的标准图像格式GIF:GraphicInterchangeFormat图形交换格式JPEG:JointPhotographicExpertGroupTI
7、F:JPEG2000:DICOM文件计算机中存储图像文件的格式。面向对象统一标识符标签与属性BasicConceptionofImageBrightnessIntensityContrastGray(GrayLevel)DefinitionResolutionCoordinateHueSaturationColorTemperaturePixelsareidentifiedbytheirposit
