stereoscopic image quality in virtual environments

67(5(26&23,&,0$*(48$/,7@ ,I WKH KRUL]RQWDO GLVSDULW\ DW D JLYHQ SRLQW LV HTXDO WR ]HUR WKH SRLQW LV LQ WKH VDPH SODFH LQ ERWK LPDJHV DQG LV SHUFHLYHGE\WKHVXEMHFWDVEHLQJFRSODQDUWRWKHVXUIDFHWKDW GLVSOD\V WKH LPDJH :KHQ WKH GLVSDULW\ LV JUHDWHU WKDQ DQG QRW HTXDO WR ]HUR WKH HOHPHQWV FDQ EH YLUWXDOO\ SRVLWLRQHG ³LQ IURQW RI´ RU ³EHKLQG´ WKH LPDJH ,I D JLYHQ SRLQW LV IXUWKHU ULJKW LQ WKH ULJKW LPDJH DQG IXUWKHU OHIW LQ WKH OHIW LPDJH LW LV VDLG WR EH ZLWK QHJDWLYH GLVSDULW\ DQG WKH RSSRVLWH VLWXDWLRQ LV FDOOHG SRVLWLYH RU FURVV  GLVSDULW\ (OHPHQWVZLWKQHJDWLYHGLVSDULW\VHHPWREH³LQIURQWRI´WKH GLVSOD\LQJVXUIDFHDQGHOHPHQWVZLWKSRVLWLYHGLVSDULW\VHHP WR EH SRVLWLRQHG ³EHKLQG´ LW >@ 7KH IROORZLQJ LPDJH LOOXVWUDWHVWKHVHVLWXDWLRQV 

c 978-1-4799-8023-9/14/$31.00 2014 IEEE

SURFHGXUH \LHOGV RQH XQZDQWHG UHVXOW WKH ERUGHUV RI WKH LPDJHVGRQRWPDWFKDQGPXVWEHWULPPHG 2WKHU PHWKRGV IRU FKDQJLQJ LPDJH GLVSDULW\ DUH DYDLODEOHEXWZLOOQRWEHFRYHUHGKHUHLQGXHWRWKHVFRSHRI WKHUHVHDUFK 

&RQYHUJHQW&DPHUDV

 )LJ  /HIW 6WHUHRVFRSLF DQDJO\SK ZKHUH ³[´ GHVFULEHV D FDVH RI QHJDWLYH GLVSDULW\ DQG ³\´ GHVFULEHV D FDVH RI SRVLWLYHGLVSDULW\5LJKW6FKHPHVKRZLQJWRSYLHZRIKRZ WKH REVHUYHU SHUFHLYHV HDFK HOHPHQW RI WKH VWHUHRVFRSLF LPDJH  

&

3DUDOOHO&DPHUDV

&

F



)LJ  &RQYHUJHQW FDPHUD VHWXS 'LVWDQFH IURP FDPHUD WR FRQYHUJHQFH SRLQW &  LQWHUD[LDO GLVWDQFH W  ILOP EDFN GLVWDQFHK IRFDOOHQJWKI YHUJHQFHDQJOHE 





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³UHDFKLQJRXW´RIWKHGLVSOD\LQJVXUIDFH 7R DYRLG WKLV SKHQRPHQRQ DQG FRQWURO LPDJH FRQYHUJHQFH VXFK LPDJHV DUH XVXDOO\ HGLWHG LQ D SURFHVV NQRZQ DV +,71 7KLV WHFKQLTXH FRQVLVWV RI VLPSO\ WUDQVODWLQJLPDJHVDFURVVWKHLU;D[HV$VWKHLPDJHVLQWKH SDLU DUH WUDQVODWHG HOHPHQWV ZKLFK DUH IXUWKHU DZD\ IURP WKHFDPHUDDUHPRYHGLQWRDVWDWHRIQHJDWLYHGLVSDULW\7KLV

 

+RUL]RQWDO,PDJH7UDQVODWLRQ

 6LPLODUO\ WR WKH SDUDOOHO FDPHUD VHWXS WKH FRQYHUJHQW FDPHUD VHWXS UHTXLUHV WZR FDPHUDV VHSDUDWHG E\ D FHUWDLQ LQWHUD[LDO GLVWDQFH7KHFDPHUDV DUHKRZHYHU WRHGLQE\D FHUWDLQ YHUJHQFH DQJOH )LJXUH  UHSUHVHQWV WKLV VHWXS 7KH YHUJHQFH DQJOH ȕ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





'HSWK%DVHG,PDJH5HQGHULQJ',%5 

7(672%-(&76

 )LJ([DPSOHRIVWHUHRSDLUFUHDWHGIRUWKHSXUSRVHRIWKLV VWXG\

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³GHSHQGV RQO\ RQ WKH UHVROXWLRQ RI WKH ILQDO LPDJH DQG QRW RQ LWV >UHQGHULQJ@ FRPSOH[LW\ OHVVHQLQJ WKH FRPSXWDWLRQDO FRVW´ >@ 7KLV WHFKQLTXH PD\ SURYH WURXEOHVRPH ZKHQ REMHFWV FRPH RXW RI RFFOXVLRQ FUHDWLQJ HPSW\ VSDFHV LQ WKH LPDJH >@>@ ,W VKRXOG EH DOVR HVSHFLDOO\ GHILFLHQW LQ WKH FDVH RI PRQRFXODU RFFOXVLRQV D FDVH ZKHUH DQ REMHFW VKRXOG EH YLVLEOH LQ RQH RI WKH YLHZV EXW QRW LQ WKH RWKHU GXH WR WKH UHODWLYH SRVLWLRQ RI REMHFWV DQG FDPHUDV QRQH RI WKH ZRUN UHVHDUFKHG SUHVHQWHG D VROXWLRQIRUVXFKVLWXDWLRQ )RUWKLVWHVWDFRPPHUFLDOO\DYDLODEOHVROXWLRQZDVXVHG QDPHO\ 2FXOD IURP 7KH )RXQGU\ 7KLV VRIWZDUH SDFNDJH KRVWV GLIIHUHQW  PHWKRGV IRU ',%5 UDQJLQJ IURP ORZHU TXDOLW\ DSSURDFKHV ZLWK IDVW UHQGHU WLPHV WR KLJKHU TXDOLW\ DSSURDFKHVZLWKVORZHUUHQGHUWLPHV,QWKLVWHVWZHXVHGWKH PHWKRG UHJDUGHG LQ WKH PDQXDO >@ DV WKH PRVW SUHFLVH QDPHGSharp Occlusions       

7R WHVW WKH VWHUHR LPDJH JHQHUDWLRQ PHWKRGV D YLUWXDO HQYLURQPHQW ZDV FUHDWHG XVLQJ D FRPPHUFLDO '&& SDFNDJH 6RIWLPDJH FDSDEOH RI ' PRGHOLQJ DQLPDWLRQ DQG UHQGHULQJ 7KH HQYLURQPHQW ZDV EXLOW XVLQJ DV D UHIHUHQFH WKH KDOOZD\ RI WKH XQLYHUVLW\ GHSDUWPHQW ZKHUH WKLVUHVHDUFKWRRNSODFHLQRUGHUWRVNLSDFRQFHSWXDOSKDVH DQGVSHHGXSWKHSURFHVV$VWKHKXPDQSHUFHSWLRQRIVWDWLF LPDJHVYDULHVVLJQLILFDQWO\IURPWKDWRIPRYLQJLPDJHV>@ DGGLWLRQDO YLUWXDO DQLPDWHG HOHPHQWV ZHUH DGGHG WR WKH YLUWXDOHQYLURQPHQWQDPHO\DIORRGRIERXQFLQJEDOOV7KH FDPHUD GHVFULEHV D WUDYHOLQJ PRYHPHQW IURP OHIW WR ULJKW DQGWKHWRWDOOHQJWKRIWKHYLGHRZDVVHFRQGV 7R JHQHUDWH VWHUHR LPDJHV XVLQJ WKH SDUDOOHO DQG WKH FRQYHUJHQWFDPHUDPHWKRGVYLUWXDOFDPHUDVZHUHSRVLWLRQHG LQ WKH YLUWXDO HQYLURQPHQW LQ WKUHH GLIIHUHQW GHJUHHV RI LQWHUD[LDO GLVWDQFHV 7KH UHVXOWLQJ UHQGHULQJ RI WKH SDUDOOHO FDPHUDV ZDV WKHQ UHFRQYHUJHG E\ +,7 WR PDWFK LQ WKH EHVWZD\SRVVLEOHWKHGLVSDULW\LQWKHFRQYHUJHQWFDPHUDV ,Q RUGHU WR JHQHUDWH WKH ',%5 VWHUHR LPDJH SDLU GDWD IURPWKHOHIWFDPHUDRIWKHSDUDOOHOFDPHUDVHWXSZDVXVHG DORQJZLWKDGHSWKPDSUHQGHUHGLQWKH'&&SDFNDJHIURP WKH VDPH FDPHUD 7KLV GDWD ZDV WKHQ SURFHVVHG XVLQJ WKH DIRUHPHQWLRQHG VRIWZDUH DQG PHWKRG ZKLFK LQ WXUQ UHQGHUHGDQHZLPDJHFRUUHVSRQGLQJWRWKHULJKWFDPHUD )RUHDFKPHWKRGLQYHVWLJDWHGWKUHHGLIIHUHQWLPDJHSDLUV ZHUH JHQHUDWHG HDFK ZLWK D GLIIHUHQW KRUL]RQWDO GLVSDULW\ 7KH ILUVW KDG D PD[LPXP GLVSDULW\ RI  RI WKH LPDJH V ZLGWK ORZ GLVSDULW\  WKH VHFRQG KDG  PHGLXP GLVSDULW\ DQGWKHWKLUGKDGKLJKGLVSDULW\ 7KHOLPLWRI  GLVSDULW\ ZDV LPSRVHG EDVHG RQ WKH IDFW WKDW VRPH DXWKRUV FRQVLGHU WKLV WR EH WKH OLPLW IRU KXPDQ FRPIRUW LQ VXFKWHVWV>@ 7KHYLUWXDOQDWXUHRIWKHHQYLURQPHQWVDOORZHGIRUYHU\ SUHFLVH FRQWURO RI WKH YDULDEOHV &DUH ZDV WDNHQ WR HQVXUH WKDWWKHKRUL]RQWDOGLVSDULWLHVZHUHPDWFKHGIRUWKHGLIIHUHQW PHWKRGVE\PHDVXULQJVXFKSDUDPHWHULQGLIIHUHQWSRLQWVRI LQWHUHVW DFURVV WKH LPDJH 2WKHU HOHPHQWV VXFK DV WKH UHVROXWLRQ FRORU DQG IRFXV ZHUH DOVR FORVHO\ PDWFKHG )LJXUH  VKRZV DQ H[DPSOH RI RQH RI WKH VWHUHR SDLUV JHQHUDWHG 

 

'LJLWDO&RQWHQW&UHDWLRQ



7KH IROORZLQJ WDEOH UDQNV DOO QLQH LPDJH SDLUV FUHDWHG DFFRUGLQJ WR WKHLU PHWKRG DQG PD[LPXP KRUL]RQWDO GLVSDULW\QRWHWKDWWKHDFURQ\PVJLYHQLQWKLVWDEOHDUHXVHG WKURXJKRXWWKLVSDSHUWRGHVFULEHHDFKVWLPXOXV 

Maximum horizontal disparity

Image generating method Convergent Parallel Low

CL Horizontal disparity 1% (of image width)

Medium

CM Horizontal disparity 2% (of image width)

High

CH Horizontal disparity 3% (of image width)

PL Horizontal disparity 1% (of image width) PM Horizontal disparity 2% (of image width) PH Horizontal disparity 3% (of image width)

7DEOH7HVW2EMHFWVE\0HWKRGDQG'LVSDULW\ 

3DUWLFLSDQW¶V)RUP 0DUNZLWKDQ;WKHRSWLRQWKDWPRVWO\UHVHPEOHV\RXURSLQLRQ UHJDUGLQJWKHSDLUVRIYLGHRV\RXDUHDERXWWRZDWFK$LVWKH ILUVWYLGHRLQHDFKVHTXHQFH%LVWKHVHFRQGYLGHRLQHDFK VHTXHQFH 3LFWXUH4XDOLW\  $LVEHWWHUWKDQ  %LVEHWWHUWKDQ  1RVLJQLILFDQW % $ GLIIHUHQFH 'HSWK4XDOLW\  $LVEHWWHUWKDQ  %LVEHWWHUWKDQ  1RVLJQLILFDQW % $ GLIIHUHQFH 9LVXDO&RPIRUW  $LVEHWWHUWKDQ  %LVEHWWHUWKDQ  1RVLJQLILFDQW % $ GLIIHUHQFH 

DIBR DL Horizontal disparity 1% (of image width) DM Horizontal disparity 2% (of image width) DH Horizontal disparity 3% (of image width)

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

3$,5('&203$5,6217(676(66,216

 )LJ  ([DPSOH RI OD\RXW RI IRUPV GLVWULEXWHG WR SDUWLFLSDQWV 7KH SDLUHGFRPSDULVRQ PHWKRG GHVFULEHG LQ >@ FRQVLVWV RI WKH IROORZLQJ SURFHGXUHV   WKH WHVW VXEMHFW LV H[SRVHGWRWKHWZRVWLPXOLEHLQJFRPSDUHGLQVHTXHQFHZLWK DQ LQWHUYDO RI WKUHH VHFRQGV EHWZHHQ WKH ILUVW DQG VHFRQG YLGHRV LPPHGLDWHO\DIWHUWKLVH[SRVXUHWKHZRUG³YRWH´ DSSHDUVRQWKHVFUHHQDQGWKHWHVWVXEMHFWVKDYHVHFRQGV WR FRPSDUDWLYHO\ HYDOXDWH WKH SHUFHLYHG TXDOLW\ GHSWK TXDOLW\DQGYLVXDO FRPIRUW RI WKHSLFWXUHV XVLQJD GLVFUHWH VFDOH ZLWK WKH IROORZLQJ RSWLRQV $ LV EHWWHU WKDQ % % LV EHWWHUWKDQ$$DQG%DUHHTXLYDOHQW)LJXUHSUHVHQWVWKH IRUPDVLWZDVSUHVHQWHGWRWKHSDUWLFLSDQWV ,PDJHVZHUHWHVWHGRQO\LQSDLUVRIWKHVDPHKRUL]RQWDO GLVSDULW\ ZLWK YDU\LQJ PHWKRGV $V DQ H[DPSOH WKH WHVWHG SDLUVIRUORZKRUL]RQWDOGLVSDULW\ZHUH&/±3/3/±&/ 3/±'/'/±3/&/±'/DQG'/±&/,WFDQEHQRWHG IURPWKLVH[DPSOHWKDWDOOVWLPXOLZHUHWHVWHGLQERWKRUGHUV $ ± % DQG % ± $ DYRLGLQJ IDOVH HYDOXDWLRQV 7R IXUWKHU DYRLG VWDWLVWLFDO HUURUV WKH SUHVHQWDWLRQ RUGHU RI DOO VWLPXOL ZDVUDQGRPL]HGDWHYHU\WHVWVHVVLRQ

 

7(6768%-(&76

3ULRU WR DVVHVVLQJ WKH TXDOLW\ RI WKH VWHUHR LPDJHV WKH WHVW VXEMHFWV ZHUH VFUHHQHG IRU YLVXDO DFXLW\ FRORU EOLQGQHVV DQGVWHUHRSVLVDSHUVRQ¶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

 

/$%25$725@>@ DOWKRXJK LQ WKLV UHVHDUFK RQO\ RQH FRPPHUFLDOO\ DYDLODEOH PHWKRG ZDV WHVWHG 7KHUHIRUH ZKLOH WKHVH UHVXOWV DUH YHU\ UHOHYDQW DV IDU DV WKH SUDFWLFH RI FUHDWLQJ VWHUHR LPDJHVLVFRQFHUQHGWKH\DUHQRWLQWHQGHGWREHFRQFOXVLYH ZLWKUHJDUG WR WKHSLFWXUHTXDOLW\ GHSWKTXDOLW\DQGYLVXDO FRPIRUWRI',%5 :LWK UHJDUG WR WKH QDWXUH RI WKH VWHUHR LPDJHV WKHPVHOYHVLWLVSRVVLEOHWKDWHOHPHQWVVXFKDVFRORUVKDSH VSHHGDQGPRYHPHQWLQIOXHQFHWKHWHVWVXEMHFW¶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

>@

>@

>@

>@

5()(5(1&(6

% 0HQGLEXUX G 0RYLH 0DNLQJ %XUOLQJWRQ )RFDO 3UHVV / =KDQJ DQG : - 7DP 6WHUHRVFRSLF ,PDJH *HQHUDWLRQ %DVHG RQ 'HSWK ,PDJHV IRU ' 79 ,((( 75$16$&7,216 21 %52$'&$67,1* YRO  QR -XQKR &0 &KHQJ 6- /LQ DQG 6+ /DL 6SDWLR 7HPSRUDOO\&RQVLVWHQW1RYHO9LHZ6\QWKHVLV$OJRULWKP )URP9LGHR3OXV'HSWK6HTXHQFHVIRU$XWRVWHUHRVFRSLF 'LVSOD\V ,((( 75$16$&7,216 21 %52$'&$67,1*YROQR-XQKR 5 /LX 2QOLQH@ $YDLODEOH KWWSZZZPHUULDP ZHEVWHUFRPGLFWLRQDU\WUDQVLWLYH >$FFHVVHG  0DUoR @ )$3)LDOKR*%UDYLDQRDQG1G6DQWRV0pWRGRVH 7pFQLFDVHP(UJRQRPLD)ORULDQySROLV ,-VVHOVWHLMQ 6XEMHFWLYH (YDOXDWLRQ RI 6WHUHRVFRSLF ,PDJHV (IIHFWV ,((( 75$16$&7,216 21 &,5&8,76 $1' 6