深入分析梳状滤波器原理Comb-filter课件

CombFilter

OutlineY-Cseparation2Dcombfilter3Dcombfilter2DadaptivecombfilterconclusionCombfilter(Y-Cseparator)Separatetheincomingcompositevideosignalintoluminance(Y)andchrominance(C).(composite)BasicconceptforYCseparate1.Frequency-notch,bandpassfilter(inearlyyears).2.Chrominance

phasedifference-combfilter(today).FrequencyLuminance&chrominancefrequencyNotch/bandpassfiltersystemsignificantoverlap,energygothrough.2DcombfilterImportantconcept…pictureinformation(y,c)isaboutthesamefromlinetoline.Specialcase(y-c,y+c).y-cy+c2ccyWhywecallita"combfilter"2Dweightingcombfilterdifferentcolorsverticallythroughthepicture.(1/4,1/2,1/4).thetransitionfromonecolortoanotherissoftened.

3Dcombfiltercompareinformationinsuccessiveframes.(odd)perfectseparationofYandCforstillframeimages(keyadvantageoverthe2Dfilter).motionorseriouscolorchanges,3Dfiltermayperformnobetterthanthe2Dfilter.hastostoretwoframesofvideodata.ProblemsVerticaldetaildifference(adjacentlines).Motiondifference(adjacentframes).Adaptivecombfilter1.Detectandselectoneform.2.Correctionterms.3.Weightingandsum.Animproved2DadaptivecombfilterOverview(modeA,B,C,D)ModeB(2Dweightingwithbandpassfilter)Normalmode,Y-Ccanbeseparatedquitewell.ModeC(2Dweightingwithoutbandpassfilter)Useunderthat3linesaresoclose.CanseparatebetterthanB.ModeD(2Dsimplecombfilter)Useunderthatdetection(2,3)dominates.DetectionalgorithmNormalway(upper).Specialdetection(bottom).Usethesetwodetections.(T1,T2,T3)YY’CYC’ModeA(detection(1,3)>T3)Whichmeanstheverticaldetaildefferenceisserious.Bandpassfilterperformsbetterthancombfilter.ModeB(detection(1,3)<T3)&(detection(2,3)>T2)Themostlyencounteredsituation.UsebandpassfiltertoeliminatelittledifferencebetweenY.YModeD

(T1<detection(1,3)<T3)&(detection(2,3)<T2)Whichmeansthatdetection(2,3)dominates.YModeDConclusion2D,3D,adaptive2D.Academic:adaptive2Dc