Asmotivatedbytheextensivepotentialapplicationsinpublicsecurity,financialsecurity,human-computerinteraction,biometricsrecognitionespeciallyfacerecognitionhasbecomeoneofthehottopicsinthefieldsofpatternrecognitionandartificialintelligence.Thisbookmainlyfocusesonfeatureextractionandclassificationalgorithmsundercomplexconditions,anditsobjectiveisthatthereaderscanquicklyunderstandthelatestfeatureextractionandclassificationmethods.Themaincontentsofthebookareasfollows:imagesynthesisandclassificationmethodbasedonquotientimagetheory;aclassificationmethodbasedonreconstructionerrorandnormalizeddistance;facerecognitionmethodbasedontheoriginalandapproximatefaceimages;enhancedcollaborativerepresentationbasedclassification;approximateandcompetitiverepresentationmethod;akerneltwo-phasetestsamplesparserepresentationmethod;quaternion-basedmaximummargincriterionmethod.《BR》Thisbookcanbeusedforpostgraduatesandseniorundergraduatesmajoredincontrolscienceandengineering.Meanwhile,itisalsoaquiteusefulreferencebookfortheresearchersintherelatedfields.