在进行图像处理时，我们经常使用飘飘欲仙的小蝴蝶图像进行测试，但网上提供的测试图标准不同。 这是Rice University提供的标准测试图，省去大家到处寻找的麻烦。 另外，仔细阅读此链接，还能找到其他有用的信息^.^原文链接： http://www.ECE.rice.edu/~ wakin/images /危机悟空/由pwetpaintthistestimagewastakenbyourgroupinduncanhallatriceuniversity.thematlabfileforthe 1024 x 1024 imageishere .负责的金鱼/sldyj/SLD yj pthereseemtobemanyversionsofthe飘逸的小蝴蝶aka ‘Lenna ) ) testimage available.thisproblemwasnotedby蓄胡子麦片in his 1993 anditremainssurprisinglytruetoday.thiswebpageisanattempttoclearupsomeoftheconfusion andhopefullynotaddtoit ) ) ) ) ) eninlosslesscompressionformats.thesecanbeimportedintomatlaboropenedusingphoto-editing software.editing ommmmandinmatlabisoftofofte stifforbmp.youmayneedtoconvertthedatatotypedoubleafterloadingit ).forExxading
LENA512=imreadLena512.BMP )；
Lena512=DoubleLena512； To write an image to a file，useimwrite:
imwriteuint8Lena512 )、’ lena512.bmp )、’ bmp )； 512 x 512 color 24位) thisseemstobeaprettywidelyacceptedstandard，whichoriginatedfromascanofthepublishedphotograph 设置
512 x 512灰色比例8位) )。
there doesn ‘ tseemtobeasmuchagreementonthisversionoftheimage.atsomepoint， theoriginalcolorimageneededtobeconvertedtograyscale.as留胡子的面粉noted optionsincludedtakingonlythegreencomponentofthergbrepreprescale orusingaluminance-only version.youcouldalsoaveragethergbcomponents，etc.I ‘ mnotsurehowthefollowingversionwasgenenerated， eachofthefollowingfilesshouldcontainthesameinformation.ifthereistrulyastandardversionofthe 512 x 512 gray scale上漂浮的小蝴蝶，thihi
PGM:Lena512.PGM262kb ) MATLAB : Lena 512.mat 262 kb ) comparing different版本
toillustratetheimportanceofusingastandardversion， let ‘ slookatafewdifferentonesthatarefloatingaround.we ‘ llcompresseachofthemusingajpeg 2000 coder obtainedfromthejasperprprojeg theimageshere.ifyouclickonthefollowinglinks，youcanseestandardjpgfiles.thesearejustforviewingandcomparisionpurpurposes-urgfiles ) ) image1 isthestandardwhichisdiscussedintheabovesection.image2 isanotherversionwhichi ‘ ve seen， anditlooksandbehavesverysimilartothestandard.image3isobtainedbytakingthegreencomponentfromthe 24位原始码描述性数据库he others，anditishardertocompress.image4isyetanotherversionthatseemstobefloatingaround.visuallyitisverydifferentfromtheotheotheotototind anditismucheasiertocompress.resultsareshownbelow.style=’ color : RGB 65255、255、255 )； font-family:Simsun； font-size:14px； ‘甜月饼/p