\00 IEEE 6th Workshop on Multimedia Signal Processing Low-delay Unconstrained Motion Compensated Temporal Filtering Technique for Wavelet-based Fully Scalable Video Coding Woo-Jin Han DM R&D Center, Samsng Electronics 1, Maetan-dong, aldl-gu, -s, Gyeogg-do, 42-742, Kore Telephone: +82-31-200-9319 Fa: +82-31-200-3427 Eail: whan.an@samsng.c tt- Among many technologie use in wa velet-based scalable ,·ideo coder, motion compensated temporal fltering (MCT) is a key technolog for both reducing temporal reun dancy and prol'iding fexible temporally scalable architecture. Howe"er, since ƣ n-ebl e temporal pyramid structure in trouce a a end-to-end delay of a size of GOP, it is "er difcult to use scalable coding technolog  many applications that require  end-to-end dla _  this paper, we po a l-la unconstraine motion compensate temporal fltering (D-UCTF) scheme. Our method fouse to control the end to-end dea in a unifed framework  el  ha"e most useful features of predicti"e coder, such  multipl e reference frame a ꭐ-a prediction. Experimental reults show that the proposed method can pro"ide comparable cd efciency and  sigifcantly smaller performance ded compared to the com'entional .   W AVELET based scalable video coding has received considerable attention fo man multimedia applica tions in erms of boh coding aloriths and standardiaion actives. Among an ecoloie used n wavelet-based scalable vi deo coders, motion coenated emoral filteing (MCTF) pposed by Ohm [1J and imped b Ch and Woods [2] s a e ecolgy for both reducng teporal redndanc and proiding feible temporally scalable archi tectre. More ecently, uconsranedMCTF(UMCTF) scheme was rpsed by Taga and Mihaela [3] to ercoe seral drabacks of oiinal MCTF scheme, such as ni-directional motion esimaion. low qalit at lwe tempoal rates, and increased dela. UCTF provides a more general fameo enabe us o e mltple refeence frames and bi-directional fltering. In the past researches, many epemental euts hae shon that he UMCTF withot update-sep perfons better than the oi ginl M.  tis reao, the specc form of UMCTF, which has no pdate-sep, is generall sed [4] athough the most general f of UMCTF alos an adaptie choice of ow-pa filters [5]. Many aplicaions that need low end-to-end dl ay, such as ideo confeencng, rere low encoder-side dela as wel as low dcode -side delay. Since both MCTF and UMCTP 11   HHHH, , I� --- ' � L H l > L H I G- � L & . (0) L " 2 [- � t � L � l � L 1 ig.    o o  M. () Encoer-side. () -.  (01 (0) . 2. π remPra    . () d-ξd. () -. analye frae from the lowet tmprl leels, he ecode side deay shold be a sie of GOP, which is unacceptable for ayeal-timeapcations. Alhogh canreduce the dla euiemet by lmitng the umber of futre referece rames, here iʦ no eplicit solution to corol the end-to-end deay. Inthis paer, pp  low-deayunconstrained mo ion compensaed temporal prediction (LD-UMCTF). which is basedon UMCTFalgorithm tocontroltheend-to-enddelayin a nifed frameork haing most se features o UMCTF,  suc asmult i pe reeenceae and -dc predicton. ! II. MC'F D UMCTP RMR  At st, we tar' from the dm of the tmoal pro cessing fo in original MCTF. In Fig. , " fre" means a lw  rey or arage frame ad "H frame" means a hgh fre-qenc or diference rame. As sonine gue,  rame p a the lowest: temporal eel ae processed irst n the encode-side, whereas hose at he ighst evel  ced firs in the de-coder side. , 0-7803-8578-0/04/$20.00 0  478