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A fuzzy motion adaptive algorithm for interlaced-to-progressive conversion

Brox Jiménez, Piedad; Baturone Castillo, María Iluminada; Sánchez Solano, Santiago

Abstract

Interlaced-to-progressive algorithms are currently required by video format conversion systems in order to display a progressive scanning used in modern visualization equipments. Deinterlacing algorithms use interpolation techniques to calculate missing pixels in transmitted fields. A motion adaptive algorithm which employs fuzzy logic to adapt the interpolation strategy to the presence of motion in the images is proposed in this paper. The performance of this new approach is evaluated by extensive simulation of different video sequences.

Full text

A Fuzzy Mo ion Adap i e Algo i hm o In e laced- o-P og essi e Con e sion P. B ox I. Ba u one S. Sánchez-Solano Ins i u o de Mic oelec ónica de Se illa - CNM – CSIC A da. Reina Me cedes S/N. Edi icio CICA 41012 Se illa (SPAIN) e-mail: [email p o ec ed] Abs ac In e laced- o-p og essi e algo i hms a e cu en ly equi ed by ideo o ma con e sion sys ems in o de o display a p og essi e scanning used in mode n isualiza ion equipmen s. De- in e lacing algo i hms use in e pola ion echniques o calcula e missing pixels in ansmi ed ields. A mo ion adap i e algo i hm which employs uzzy logic o adap he in e pola ion s a egy o he p esence o mo ion in he images is p oposed in his pape . The pe o mance o his new app oach is e alua ed by ex ensi e simula ion o di e en ideo sequences. Keywo ds: Mo ion adap i e, de-in e lacing, uzzy in e ence sys ems. 1 In oduc ion Mo ion de ec ion is c ucial o many undamen al asks in image p ocessing (such as de-in e lacing [1] o pic u e a e-up con e sion [2]) which eso o he in e pola ion o image sequence da a o inc ease he e ical esolu ion o he image (de-in e lacing) o he numbe o pic u es which compose he ideo sequence ( a e-up con e sion). Mo ion adap i e in e pola ion echniques p o ide e icien solu ions o his kind o p oblems because hey allow o apply di e en in e pola ion algo i hms in he s a ic and dynamic pa s o he images. Ob iously, hei pe o mance elies s ongly upon he quali y o mo ion de ec ion schemes. Mo ion de ec o s basically e alua e he di e ence be ween pixels in consecu i e pic u es o make a decision. Howe e , due o noise and e ical de ails, his alue may no be a good measu emen . To inc ease he obus ness o mo ion de ec o s, se e al p oposals ha e been desc ibed in he li e a u e. Some examples a e he use o a low-pass il e o educe luc ua ions o he alues nea edges, o he linea combina ion o se e al de ec o ou pu s [2]. Fuzzy logic has also been applied o de ec mo ion in o ma con e sion sys ems which ake ad an age o i s in e pola ion capabili y o ob ain new da a in a eas whe e he decision is no i ial. Techniques desc ibed in [3] and [4] p opose uzzy mo ion adap i e algo i hms o de-in e lacing. In e laced o ma was in oduced o hal e he equi ed bandwid h in cu en TV sys ems (NTSC, PAL). I consis s in ansmi ing ields wi h he hal o he lines ins ead o he whole ames. A he ecei e side, a de-in e lacing (o in e laced- o-p og essi e con e sion) algo i hm econs uc s he missing lines applying in e pola ion echniques. Figu e 1 illus a es his p ocess. The ad en o HDTV sys ems, high Figu e 1: De-in e lacing ask quali y moni o s, displays and p ojec o s has inc eased he need o de-in e lacing algo i hms in he las ew yea s. Linea de-in e lacing echniques, which always pe o m he same kind o in e pola ion be ween pixels, ha e been widely applied. Among hem, empo al algo i hms (such as ield inse ion) exploi he co ela ion in he ime domain achie ing good esul s in s a ic a eas bu in oducing e y annoying e ec s in mo ing a eas o he image. Spa ial in e pola ion algo i hms (such as line doubling o line a e age) p esen as main ad an age hei low implemen a ion cos , since memo y is no equi ed o s o e p e ious ields. Howe e , hey in oduce blu ing and s ai s-case e ec in e ical de ails and edges. Theo e ically, a linea combina ion o bo h echniques should p o ide he bes esul s. To p o ide i , mo ion adap i e in e pola ion echniques we e in oduced. A no el mo ion adap i e in e pola ion algo i hm is p oposed in his pape . I uses a uzzy in e ence sys em o decide he mos con enien in e pola ion acco ding o he p esence o mo ion. The pape is o ganized as ollows. Sec ion 2 includes he desc ip ion o he algo i hm and i s applica ion o de-in e lace ideo sequences. The pe o mance o he new algo i hm, compa ed wi h o he s o simila complexi y in e ms o memo y equi emen s, is e alua ed in Sec ion 3. Finally some conclusions a e gi en in Sec ion 4. 2 Fuzzy Mo ion Adap i e Algo i hm The idea o mo ion adap i e algo i hms o de- in e lacing was o iginally desc ibed in [5]. I basically consis s in using wo di e en in e pola o s, one o s a ic a eas and ano he one o mo ing a eas. The main no el y o ou p oposal is o use h ee ins ead o wo kinds o in e pola o s depending on he le el o mo ion in he pic u e. This is ca ied ou by using a uzzy logic-based in e ence sys em o apply he ollowing heu is ic knowledge in o de o e alua e he missing pixels in a ield: 1) I mo ion is small hen he bes op ion is o use in o ma ion om p e ious ields pe o ming a empo al il e ing (IT) as in e pola ion me hod. 2) I mo ion is la ge hen he bes op ion is o use in o ma ion om he cu en ield pe o ming a spa ial il e ing (IS) as in e pola ion me hod. 3) In o he cases, he mo ion is medium and a linea combina ion o he spa ial and empo al il e ing will be he bes op ion. These ules, summa ized in Table 1, allow imp o ing he esul s o con en ional mo ion de ec o s p o iding smoo h ansac ions be ween he h ee in e pola o s. To achie e i , he uzzy se s illus a ed in Figu e 2 a e used o ep esen he concep s “SMALL”, “MEDIUM”, and “LARGE”, ins ead o h eshold alues. Table 1: Fuzzy ule se o he p oposed algo i hm i mo ion (x,y, ) hen I(x,y, ) SMALL c1 = IT(x,y, ) LARGE c2 = IS(x,y, ) MEDIUM c3 = γ IT(x,y, ) + λ IS(x,y, ) The inpu o he sys em is he bi-dimensional con olu ion o he di e ence o luminances, Hij, gi en by he ollowing exp ession: Figu e 2: Membe ship unc ions o he uzzy mo ion adap i e sys em () 2 )1,,()1,,( ),,( 121 242 121 16 1 1 )1,1,1(),,1()1,1,1( )1,1,(),,()1,1,( )1,1,1(),,1()1,1,1( 1),,( 3 1 3 1 +−− =           =           −+++−−+ −+−− −+−−−−− =         =∑∑ == yxI yxI yxHC yxH yxH yxH yxH yxH yxH yxH yxH yxH H CH yxmo ion i ij j ij () ()() () ()()() 3,,),,(,, ,,),,(,,),,( 32 31 yx yx yxI yx yx yxI yxI S T αλα α γ α ⋅+⋅ +⋅+⋅= whe e x and y a e he spa ial coo dina es o he p ocessed pixel in a ame, and de e mines he o de o he ield in he sequence. Bi-dimensional con olu ion is e y sui able o measu e mo ion since i conside s he spa ial and empo al neighbo hood o he cu en pixel. Besides, i p o ides high lexibili y because con olu ion weigh s, Cij, allow gi ing mo e p io i y o nea es pixels in he neighbo hood. Exp ession (1) shows one o he bi-dimensional con olu ion windows which ha e been used. Conside ing his exp ession, pixels (in da k g ey) shown in Figu e 3 a e aking pa in he bi- dimensional con olu ion. A s udy using con olu ion windows wi h di e en sizes is p esen ed in Sec ion 3. The luminance componen o he in e pola ed pixel is calcula ed applying he Fuzzy Mean de uzzica ion me hod as ollows: whe e αi a e he ac i a ion deg ees o each ule. Subs i u ing he consequen s, ci (see Table 1), and applying ha α1+α2+α3 is always equal o 1, he abo e exp ession can be gi en as: Figu e 4 shows he block diag am o he uzzy mo ion adap i e algo i hm. Acco ding o (3), he algo i hm applies a empo al il e ing i he bi- dimensional con olu ion o he di e ence o luminances is eally small (α1 is equal o 1 and he es o αi a e 0). I pe o ms a spa ial il e ing i he mo ion le el is eally la ge (α2 akes he alue 1 and he o he s αi a e 0). O he wise wo ules a e ac i a ed and a non- linea combina ion be ween wo o he h ee consequen s is applied. F om he desc ip ion o he uzzy sys em, di e en h eshold alues H1, H2 and H3 a e used in he desc ip ions o membe ship unc ions o “SMALL”, “MEDIUM” and “LARGE” (see Figu e 2). Rega ding he consequen s o he uzzy ule se , he pe o mance o he uzzy mo ion adap i e algo i hm also depends on he pa ame e s γ and λ, which de e mine he hi d in e pola o unc ion as a linea combina ion o he in a- ield (IS) and in e - ield (IT) me hod. Despi e he e is no es ic ion o de e mina e hese i e alues, some o hem achie e be e esul s han he o he ones. In o de o es ima e hese alues, a se o inpu /ou pu aining pa e ns om p og essi e ideo sequences is used o minimize an e o unc ion be ween he o iginal alues (ob ained om he p og essi e ideo sequences) Figu e 3: Pixels in da k g ey a e aking pa in bi-dimensional con olu ion Figu e 4: Block diag am o he uzzy mo ion adap i e algo i hm ()() () () 2 ,, ,,,, ),,( 3 1 3 1 ∑ ∑ = = ⋅ = i i i ii yx yxc yx yxI α α and he in e pola ed ones. This is ca ied ou pe o ming a supe ised lea ning algo i hm. In o de o ealize i , he de elopmen en i onmen X uzzy 3.0 is used [6]. I is a whole en i onmen o designing uzzy se s ha is composed o a se o CAD ools co e ing he di e en s ages o desc ip ion, e i ica ion, simpli ica ion and syn hesis o in e ence sys ems based on uzzy logic. X uzzy 3.0 is ee so wa e and i can be downloaded om he web page: h p://www.imse.cnm.es/X uzzy. X uzzy 3.0 in eg a es a CAD ool, x sl, o une uzzy sys ems desc ibed in XFL ( he speci ica ion language in X uzzy) [7]. Conside ing ha ule consequen s could be desc ibed as linea unc ions o he e inpu a iables (IT, IS and mo ion), he uzzy sys em has been pe o med wi hin X uzzy as a i s - o de Takagi-Sugeno sys em. To achie e i , he ule se in Table 1 has been ansla ed in o he equi alen one shown in Table 2, whe e he membe ship unc ion called “DUMMY” e u ns a alue o one independen ly o he inpu alue. This is necessa y o include he inpu a iables IT and IS in he an eceden s o he ule se . Figu e 5 illus a es he g aphical use in e ace o he CAD ool x edi wi hin X uzzy 3.0 which eases he desc ip ions o he ule se . x sl allows he use di e en lea ning algo i hms as well as uning only speci ic pa ame e s o he sys em and a selec ing c i e ion o s op he p ocess. In pa icula , he well-known Ma qua d -Le enbe g algo i hm is chosen and he pa ame e s H1, H2, H3, λ and γ a e enabled o pa icipa e in he uning p ocess. Figu e 6 shows he e olu ion o h ee e o unc ions along he lea ning p ocess a e ele en i mo ion (x,y, ) and IS(x,y, ) and IT(x,y, ) hen I(x,y, ) SMALL and DUMMY and DUMMY c1 = IT(x,y, ) LARGE and DUMMY and DUMMY c2 = IS(x,y, ) MEDIUM and DUMMY and DUMMY c3 = γ IT(x,y, ) + λ IS(x,y, ) Table 2: Desc ip ion o he uzzy sys em ule se wi h X uzzy3.0 Figu e 5: Desc ip ion o he uzzy ule se using x edi wi hin X uzzy 3.0 () 5 11111 12321 13631 12321 11111 42 1 3                 =C () 4 111 232 363 232 111 32 1 2                 =C i e a ions. Compa ing wi h o he uzzy mo ion adap i e algo i hms, ou p oposal educes conside ably he compu a ional complexi y o he me hod in [3] (i will be p o ed in he Sec ion 3). The bi- dimensional con olu ion o he di e ence ma ix was i s ly in oduced in [4] o compu e he se o uzzy in e ence o ules. In ou case, his ope a o is used as inpu o he uzzy sys em o dis inguish he di e en le els o mo ion in he image. 3 Simula ion esul s The simula ion esul s p esen ed in his sec ion allow compa ing ou p oposal wi h o he de- in e lacing algo i hms. In o de o employ an objec i e pe o mance measu emen , o iginal p og essi e ideo sequences whose e en/odd lines we e p e iously elimina ed ha e been de- in e laced and an e o unc ion has been employed o e alua e he beha io o di e en de-in e lacing algo i hms. The p oposed algo i hm has been compa ed wi h line doubling, line a e age, ield inse ion, VT il e ing using wo [8] and h ee ields [9] and he wo uzzy mo ion adap i e algo i hms p oposed in [3] and [4]. The h ee mo ion adap i e algo i hms use he same in e pola o s: line a e age as spa ial il e ing and ield inse ion as empo al il e ing (as i was explained in Sec ion 2, ou app oach uses a linea combina ion o bo h echniques as hi d in e pola o ). Di e en sizes o he con olu ion windows ha e been conside ed o ou me hod: 3x3, 5x3 and 5x5. The weigh s o he new ma ices 5x3 and 5x5 a e shown in exp essions (4) and (5), espec i ely. They ha e been selec ed empi ically, gi en mo e p io i y o closes pixels in he neighbo hood. Ob iously, when he window size is bigge , mo e pixels a e Figu e 6: E olu ion o he uning p ocess conside ed o e alua e mo ion wi h he co esponding inc ease in he compu a ional cos . Table 2 shows he a e age PSNR alues ob ained when de-in e lacing he ields o se e al s anda d ideo sequences. Th ee ows, co esponding o he h ee bi-dimensional windows used o ou p oposal, a e included in he able. The PSNR esul s show ha he new algo i hm pe o ms be e han all he o he algo i hms∗. The inclusion o a hi d consequen inc eases he obus ness o he mo ion de ec o ob aining highe PSNR alues han he o he wo uzzy mo ion adap i e algo i hms. This cha ac e is ic can be also co obo a ed wi h he de-in e laced images showed in Figu e 7 and Figu e 8 (especially in ma ked a eas wi h whi e ci cles). Rega ding he h ee op ions o ou p oposal, he me hod which wo ks wi h a bigge bi-dimensional con olu ion window achie es he bes esul s. Ne e heless, no only quali y pe o mance bu also compu a ional ime and cos should be ∗ In spi e o he e a e o he pe cep ual measu es, he majo i y o esea ch communi y in image p ocessing use he PSNR o es ima e he quali y o he econs uc ed image. e alua ed. This is he eason why all hese algo i hms ha e been p og ammed in Ma lab and execu ed on he same PC (a 2.0 GHz Pen ium 4 p ocesso unning he MS-Window XP ope a ing sys em). The o al CPU ime and he compu a ional ime a io acco ding o he as es algo i hm a e shown in Table 3. Mo eo e , he complexi y is also e alua ed in e ms o memo y equi emen s as i is shown in Table 4. Compa ing wi h he VT (3 ields) algo i hm (widely used in TV indus y), ou p oposal equi es an ex a- ield memo y since ou ields a e used o e alua e he amoun o mo ion. Howe e , i inc eases conside ably he de ec ion o mo ion. 4 Conclusions A no el mo ion adap i e algo i hm o de- in e lacing has been p esen ed in his pape . I employs a uzzy sys em which model heu is ic knowledge o classi y di e en a eas in he ield acco ding o he p esence o mo ion. Di e en in e pola ions a e applied depending on his classi ica ion. Field inse ion is pe o med in s a ic a eas, line a e age in mo ing a eas, and a combina ion o bo h in he es o he image. As a esul , he p oposed me hod p o ides be e solu ions elimina ing he blu ing and he Video Sequence Missa Pa is T e o Salesman News Mo he Ca phone Fo ma CIF (288x352) QCIF (144x176) Line Doubling 36.44 23.61 31.05 29.75 25.18 31.81 28.25 Line A e age 40.47 26.67 35.04 33.53 29.25 35.94 32.61 Field Inse ion 38.36 29.86 34.36 36.17 33.13 36.14 30.34 VT 2 ields 40.25 30.73 36.61 36.54 35.46 39.61 34.08 VT 3 ields 40.52 31.37 37.16 36.95 35.67 40.89 34.54 Fuzzy Mo ion Adap i e [3] 40.01 33.12 35.38 37.62 34.73 39.49 32.27 Fuzzy Mo ion Adap i e [4] 40.18 35.28 36.69 38.29 37.51 41.87 34.78 P oposed 1 (3x3) 40.51 35.78 37.49 38.44 38.68 41.93 34.83 P oposed 2 (5x3) 40.58 35.93 37.61 38.49 38.91 42.02 34.92 P oposed 3 (5x5) 40.63 35.99 37.68 38.55 38.97 42.05 34.97 Table 2: A e age PSNR ( alues in dBs) when de-in e lacing se e al ideo sequences annoying s ai s-s ep e ec o he de-in e laced images. Besides, i is achie ed a he expense o a low inc emen in he complexi y. Acknowledgemen s The au ho s wish o exp ess hei g a i ude o D . J. Gu ié ez-Ríos o his encou agemen s and ad ices. This wo k has been pa ially unded by he p ojec s TEC2005-04359/MIC om he Spanish Minis y o Educa ion and Science and TIC2006-635 om he Andalusian Regional Go e nmen . The i s au ho is also suppo ed by he Spanish Minis y o Educa ion unde he p og am F.P.U. o Phd. S uden s. Re e ences [1] G. De Haan and E.B. Belle s. De- in e lacing: An o e iew. P oc. o he IEEE, ol.86, pp.1839-1857, Sep .1988 [2] G. De Haan. Video p ocessing. Uni e si y P ess, Eindho en, 2004. [3] D. Van de Ville, B. Rogge, W. Philips and I. Lemahieu. De-in e lacing using uzzy-based mo ion de ec ion. P oc. 3 d In . Con . on Knowledge-Based In elligen In o ma ion Enginee ing Sys ems, pp.263-267, Adelaide, Aus alia, Aug. 1999 [4] J. Gu ié ez-Ríos, F. Fe nández-He nández, J. C. C espo and G. T e iño. Mo ion adap i e uzzy ideo de-in e lacing me hod based on con olu ion echniques. P oc. o In o ma ion P ocessing and Managemen o Unce ain y in Knowledge-Based Sys ems, Pe ugia, I aly, July 2004 [5] A. M. Bock. Mo ion adap i e s anda ds con e sion be ween o ma s o simila ield a es. Signal P ocessing: Image Communica ion, pp.275-280, ol.6 no.3, June 1994 [6] F.J. Mo eno-Velo, I. Ba u one, S. Sánchez- Solano, A. Ba iga. Rapid design o complex uzzy sys ems wi h XFUZZY, P oc. IEEE In . Con . on Fuzzy Sys ems, pp.342-347S . Louis, USA, May 2003 [7] F.J. Mo eno-Velo, I. Ba u one, R. Senhadji and S. Sánchez-Solano. Tuning complex uzzy sys ems by supe ised lea ning algo i hms, P oc. IEEE In . Con . on Fuzzy Sys ems, pp.226-231, S . Louis, USA, May 2003 [8] Genesis Mic ochip, Inc., P elimina y da a shee o Genesis gmVLD8, 8 bi digi al ideoline double , e sion 1.0, June 1996 [9] M. Wes on. In e pola ing lines o ideo signals. US-pa en 4, 789-893, Dec. 1998 Line Doub. Line A e . Field Inse . VT 2 ields VT 3 ields Mo ion adap.[3] Mo ion adap.[4] P oposed Algo i hm 3x3 5x3 5x5 CPU ime (s) 2.03 2.05 3.28 10.62 14.65 143.03 29.21 30.95 31.71 32.14 Ra io 1 1.01 1.61 5.23 7.21 70.42 14.37 15.25 15.62 15.82 Table 3: Compu a ion ime equi ed by de-in e lacing algo i hms Line Doub. Line A e . Field Inse . VT 2 ields VT 3 ields Mo ion adap.[3] Mo ion adap.[4] P oposed Algo i hm 3x3 5x3 5x5 Field Memo ies 0 0 1 1 2 3 3 3 3 3 Line Delays 0 1 0 1 2 0 0 0 0 2 Pixel Delays 0 0 0 0 0 4 4 2 4 4 Table 4: S o age de ices Figu e 7: (a) P og essi e ame o “Ca phone” sequence. (b) The co esponding in e laced ield. De-in e laced image applying: (c) line doubling, (d) line a e age, (e) ield inse ion, and ( ) VT il e in g 2 ields Figu e 8: De-in e laced image applying: (a) VT il e ing 3 ields, (b) uzzy mo ion adap i e in [3] and (c) in [4], p oposal wi h 5x5 (d), 5x3 (e) and ( ) 3x3 window