简介:Inthispaper,anewtechniqueisproposedforrotation,scalingandtranslation(RST)invariantimagewatermarkingbasedonlog-polarmappings(LPM)andphase-onlyfiltering(POF).ThewatermarkisembeddedintheLPMofFouriermagnitudespectrumoftheoriginalimage,andasmallportionofresultingLPMspectrumisusedtocalculatethewatermarkpositions.Thistechniqueavoidscomputinginverselog-polarmapping(ILPM)topreservethequalityofthewatermarkedimage,andavoidsexhaustivesearchtosavecomputationtimeandreducefalsedetection.Experimentalresultsdemonstratethatthedigitalwatermarkingtechniqueisinvariantandrobusttorotation,scaling,andtranslationtransformation.
简介:Pointeranalysisisatechniquetoidentifyatcompile-timethepotentialvaluesofthepointerexpressionsinaprogram,whichpromisessignificantbenefitsforoptimizingandparallelizingcompilers.Inthispaper,anewapproachtopointeranalysisforassignmentsispresented.Inthisapproach,assignmentsareclassifiedintothreecategories:pointerassignments,structure(union)assignmentsandnormalassignmentswhichdon'taffectthepoint-toinformation.Pointeranalysesforthesethreekindsofassignmentsrespectivelymakeuptheintegratedalgorithm.Whenanalyzingapointerassignment,anewmethodcalledexpressionexpansionisusedtocalculateboththelefttargetsandtherighttargets.Theintegrationofrecursivedatastructureanalysisintopointeranalysisisasignificantoriginalityofthispaper,whichuniformsthepointeranalysisforheapvariablesandthepointeranalysisforstackvariables.ThisalgorithmisimplementedinAgassiz,ananalyzingtoolforCprogramsdevelopedbyInstituteofParallelProcessing,FudanUniversity.Itsaccuracyandeffectivenessareillustratedbyexperimentaldata.
简介:Inthispaper,anewalgorithmforrepresentingconicspreciselyispresentedusingNURBSofdegreetwo.Thealgorithmrequiresonlyfourcontrolvertices,whichistheminimumnumberofcontrolverticescomparedwiththeotheralgorithmsusingthesquarecontrolverticeconfiguration,torepresentafullcircleusingthefullcircumscribingsquarebasedrepresentation.Thispaperalsoderivesanewcon-ditionforNURBStopreciselyrepresentconicsandshowsthenecessaryandsufficientconditionofrep-resentationofacirculararc.
简介:ANEWCONVEXHULLALGORITHMFORANYPOLYGONHuZhanqiLiYupengWangJunQiaoLeiAbstractAnewalgorithmforfindingconvexhulofapolygonispropose...
简介:Astudyhasbeenconductedonthealgorithmofsolvinggeneralizedoptimalsetofdiscriminantvectorsinthispaper.Thispaperproposesananalyticalalgorithmofsolvinggeneralizedoptimalsetofdiscriminantvectorstheoreticallyforthefirsttime.Alotofcomputationtimecanbesavedbecauseallthegeneralizedoptimalsetsofdiscriminantvectorscanbeobtainedsimultaneouslywiththeproposedalgorithm,whileitneedsnoiterativeoperations.Theproposedalgorithmcanyieldamuchhigherrecognitionrate.Furthermore,theproposedalgorithmovercomestheshortcomingsofconventionalhumanfacerecognitionalgorithmswhichwereeffectiveforsmallsamplesizeproblemsonly.ThesestatementsaresupportedbythenumericalsimulationexperimentsonfacialdatabaseofORL.
简介:Inthispaper,twoapproachesareusedtosolvethePerspectiveThree-PointProblem(P3P):thesymboliccomputationapproachandthegeometricapproach.Inthesymboliccomputationapproach,weuseWu-Ritt'szerodecompositionalgorithmtogiveacompletetriangulardecompositionfortheP3Pequationsystem.ThisdecompositionprovidesthefirstcompleteanalyticalsolutiontotheP3Pproblem.Inthegeometricapproach,wegivesomepuregeometriccriteriaforthenumberofrealphysicalsolutions.Thecompletesolutionclassificationfortwospecialcaseswiththreeandfourparametersisalsogiven.
简介:Thispaperpresentsanewclassofsurfacesthatgivetwoquitedifferentappearanceswhentheyareseenfromtwospecialviewpoints.Theinconsistentappearancescanbeperceivedbysimultaneouslyviewingthemdirectlyandinamirror.Thisphenomenonisanewtypeofopticalillusion,andwehavenameditthe"ambiguouscylinderillusion",becauseitistypicallygeneratedbycylindricalsurfaces.Weconsiderwhythisillusionarises,andwepresentamathematicalmethodfordesigningambiguouscylinders.
简介:Multiway决定图(MDG)是排序许多的一阶的逻辑的一个子集的一个正规代表。这个子集与抽象类型和uninterpreted功能符号概括平等的逻辑。在抽象、具体的排序之间的区别反射在数据路径和控制之间的硬件区别。这里,我们认为方法改进MDG建设。效率通常通过Generalized-If-Then-Else(GITE)的使用被完成在二进制决定图包裹的操作员。因而,我们考察为MDG确认技术使用的主要算法。特别地,关系产品并且由包含修剪算法通过将导致更有效的实现的这个单个GITE操作员一致地被定义。而且,我们提供他们的正确性证明。这个工作能被看作使ROBBD算法适应抽象种类和uninterpreted功能的领域的一个方法。新工具,叫的NuMDG,接受一种扩大SMV语言,支持抽象数据排序。最后,我们表明NuMDG工具的效率并且从SMV用一套基准评估它的表演的现在的试验性的结果包装。