Three Dimensional Interpolation of Video Signals

Transcription

1 Three Dmesoal Iterpolato of Vdeo Sgals Elham Shahfard March 0 th 006

2 Outle A Bref reve of prevous tals Dgtal Iterpolato Bascs Upsamplg D Flter Desg Issues Ifte Impulse Respose Fte Impulse Respose Desged softare demostrato Cocluso ad Future ors

3 Vdeo Sgal defto A vdeo frame s a pcture made up of a D dscrete grd of pxels. A vdeo sequece s a collecto of frames th equal dmesos dsplayed at fxed tme tervals.

4 Vdeo Coverso Prcpal Challeges

5 Three-Dmesoal Dgtal Iterpolato Defto: Dgtal terpolato s the process of creasg the samplg rate of dgtal sgal Possblty: From samplg theorem e o that t s possble Applcatos: Improve the sgal resoluto Worg th mult-rate sgals Compresso Implemetato steps: UpSamplg Zero Paddg Lo Pass Flterg

6 UpSamplg

7 Lo Pass Flterg

8 Iterpolato of a D sgal As D terpolato: The frequecy spectrum of the output ll be detcal to orgal sgal The samplg rate ll be creased each dmeso. There ll be M mage of the orgal spectrum the same rage. We should desg a stable D recursve flter th a ear lear phase respose for LPF part.

9 D Dgtal Flters D flters Produce a D array of umbers he gve a D put array cosderg a D lear system the output ca be expressed as y h * x Are categored as recursve ad o-recursve flters Recursve flters Ifte Impulse Respose IIR the output s a eghted average of preset ad past puts as ell as past outputs o-recursve flters Fte Impulse respose FIR output s a eghted average of preset ad past puts

10 D Ifte Impulse Respose Flters Output ad Frequecy Respose of a D causal IIR flter ca be expressed as: Advatages Desg Flexblty Loer order flters Dsadvatages Iheret stablty Iheret o-lear phase respose + b a H y b x a y

11 D Fte Impulse Respose Flters Output ad Frequecy Respose of a D causal FIR flter ca be expressed as: Advatages Stablty Iheret lear phase respose Dsadvatages Hgher order flters are requred trasto bad costrat h H x h y

12 D Flters Desg Methods FIR flters desg methods Desg Usg Itegrato Desg Usg FFT ad Wdo fuctos McClella Trasformato Lear Programmg IIR flters Desg Methods: Lear Programmg Blear Trasformato Modfed Shas Method

13 Modfed Shas Method Could be used to desg a stable IIR flter th ear lear phase respose Is based o mmg a eghted error fucto

14 Modfed Shas Method From prevous equatos e o that a IIR flter frequecy respose ca be rtte as: T T T T T T T T T e e e b B e e e a A here B A H e e e by substtutg b a H + +

15 Modfed Shas Method The resultg sets of equatos ll be olear M M M d d Q h b a h h h B A H ε δ ε ε

16 Modfed Shas Method To avod olearty e may cosder eghted error fucto } { } { 0 0 ˆ ˆ ˆ b for lear equato a lear equato b Q h b a a Q Q a h b A H B B xy d xy M M M d d ε δ ε ε ε

17 Implemetato Start Obta Stadard AVI Fles Extract dvdual Frames Extract Ra Vdeo Data Extract dvdual Frames Apply D Flter Ed Recostruct AVI Fles Recostruct dvdual frames

18 Rug Computer Implemetato Ru the program

19 Coclusos ad future ors After applyg the desged D flter to vdeo data the resoluto each drecto s creased by a factor of to total resoluto mprovemet of factor 8 Zoomg out the orgal vdeo ad comparg t th the fltered oe shos the mprovemet resulted from usg tme doma data The algorthm should be mproved to be faster The buffer se problem should be solved The problems regardg ts effcecy use th dfferet aspect ratos should be solved

20 Refereces [] M. A. Sd-Ahmed Image Processg: Theory Algorthms ad Applcatos McGra Hll e Yor 994. [] R. Kg M. Ahmad R. Gorgu-agub A. Kabe M. Am-Saad Dgtal Flterg Oe ad To Dmesos: Desg ad Applcatos Pleum Press e Yor 989. [] A. Atoou Dgtal Flters: Aalyss Desg ad Applcatos McGra Hll Toroto 99. [4] S. B. McFadde Multmeda Applcatos of Three Dmesoal Dgtal Flters M.Sc. Thess Uversty of Wdsor Wdsor 000. [5] J. Shas S. Tertel J. Justce Stablty ad sythess of todmesoal recursve flters IEEE Tras. o Audo ad Electroacoustcs vol. 0 Issue pp