￨

Irllage‐processingtechniques for a consumer video printerIIirOshi KanO

ハbsrracf̲̲The image‐ processing techniques used in a newly developed video printer are described.

Hideto Fttita

The amOunt OFirnage data is reduced by subsamp:ing the chrominance signals and by data compres‐(yoshi FukushiRnasion.The DPCM algorithm is usod fOrthe cOmpression.A fie:d‐interpo!ation a180rithm that takes into
account the correlation between diagona!dots is prOposed.This algorithm is simple and has better

Kazuo lto

spatia:―frequency characteristics than the bi―!inear interpo!ation a!80rithm.A co!o「signa!‐
conversion
circuit that enables users to adiust the cO10ra tint′
contrast′and luminance after capturing an image
is a!so described.
κe/WOrds̲color vidcc hrd cοηlage cοmρ ressbЛ′1/ideO′
mage caρ fure.
ρ″ ′reducti()n tccllni(lueS a110w fOr thc POssibility othc tOtal sizc Of bOth itnttgc‑lnelnory and image―reduction
There is an increasing:lccd tO obtaill c01or llard cOPies Of circuits.
videO signals fr01n high―ilnagc―
quality videO c(luiPnlent
The digital image―PrOceSSing techniques used in therccordcrs.of thc valriOlis
Rs and Hi8 canlcrtl―
such as s̲vHS V(〕
Printer are:non‑lmpact prillting systeins,the sublimatioll clye tllerlllal(1)Data reductiOn Of chrOmina1lce signals.
ler vi(leotransfer prOcess is the inOst suitable for a cOnsul■(2)A ricl(1̲illt(lrl)01:ltiOn tllgOritlinl th:tt
sth()
prilltcr beca1lsc thc l)rilltillg l)roc('SS :111(1()ffK):・
is si11lPl(〕(・(lttti011 1)ct、
Oll‖t ll:(l cO:・
:・
vccn diagOnal dots.

lintroduction:配 ‖ ‰ :::I‖ よ∫ittI置

尋 t鰤

糧

]:ILil‖(3)Color convcrsion from Y,R― ヽ and B―Y(lumi―
nancc and chrOmillancc)data to CMY data after
capturing an ilnage.
(4)I1lorizontal alld vertical edgc enhancement.

i

1露
翼
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lお
‖
撫ユ
慧IIttlll蹴滞UtI翼

hnage‐PrOceSSing techniqucs arc not used sufficiently to∬鳳 棋1鷲淵 W…

Tllis PaPcr describes the system cOnfiguratiOn andult thesc tcchni(lucS・
岬 祠 闇鋤ffic・

For consumer video prillters that are mainly used

2

Systern conf:guration

焦漱ktle conJder the folbwing Pdnts to bc very晨鍛
° tⅧ 蹴鰍 よい ℃柿呼肌The specificatiOns ofthe videO printer are showll in Table land the circuit b10ck diagraln ofthe system is shown in Fig.
1.Thc systenl consists of a videO interface,a data̲colnpres―S10n PК)Cesso■ an Hnage ineinolyl a11 1lnage processo■ a(2)An advanccd ficld― intc■)OliltiOn algOrithill shOul(1 prillt―
cngillc PrOCCSso■ :lnd a thcrlllal head.

ed 叩
a.σ
面ng mlsignal and Y/C separate signals and decOdes thein tO analog
lllttri:鵠
。麗l∝collvCrSiO:l ttigOritll11ls
The vidcO interfacc acccPts both NTSC COmpOsite video

llnagc l)ccttusc tlny color―工

ll― 工 tllld B一

PL‖
t」
1 :I」
I
t寵
:為
: II‖
miふ黒(精mlDts to℃
面に喘器 kl声淋豊llぱR一 ヽ and B一

Y signtlis.Thcn,tllc analog工Ysignals ttrc cOnvcrtc(l to(ligita1 11‑111ヽ11nd B―Y(1llta,tlnd()(ltO thc(Llttt―:t1lslbl・『
t:・
c()nll)rcsS101｀
ProceSSOr.Y:R‑1l an(1low)(lttttt or tl c()k)rl)rilltCr tlrc inll)cribCt
13‑Y ttt
ttrcPrC‐thc 11llllillュ
1、
cC and Chrolninallce rcprcsentations of
the NTSCヽ Prilnary co10rs.

(4)1lnage̲Processing tcchniques shOuld l)e fuHy used
TABLE l ――Specifications of the printertO enhancc ilnage quality.
Zc have dcvcloPcd a new cOnsulllcr vidcO Prilltel・ヽヽwhich featurcs lligh illlagc quality9 casc of()Pcrati011,an(1C01nPactncss. E)igital ilntlgc Proccssillg is used to illlPrOVe
the ilnage qualitヌand the flcxibility of digital Ocessing
Pl・
alsO cOlltHbutes to the casc Of opcration. Moreove■data‐1):illting systelll
Vi《l(10 illPlits
Prillt:tre:lllesohitio11(〕
rtツievel
Di:netis:o:lS

Tllcrinal dye transfer
NTSC co:nPosite alld S
88 x l15 1nin
5.4 dots/mm
128 1evels/color
420× 110x 350 mm

reccived 9/11/91;revised 1/29/92.
atthe 1991 S:D:nternational Symposium′
Revised version of paper l1 presented
6′
Hirakata′
nyo[lectric CO′Ltd., 1‐
18‑1 3 Hashiridani′
The authors are with the Human Sciencc Laborator"Control&Systenls Research ContcL St■
720‑41‑1416
720‐41‐1284′Fax 81‐
Osaka′573′,apanitelephone 81‐∝ opyright 1 993 Society for lnformation Display o734‑1768/93/0101‑0097Sl.00

1/1,1993
10urnal of the S![)′

‐
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97

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POSitC Vi(lcO n10dc1 1las tlle snlaHcst size but thc illlage(11lality is thc、
vOrst l)cctlllsc(luantiZatlon error in digitizing

Vidco lnput

thc co:1lPoSite vi(lco signtli causcs Y/C scParation error and101・
covCt this lllodCI has(lificulty in adaPtillg
cO10r sllill.Ⅳ
Thc Only wtty is to add thc Y/CtO thc Y/C scPilrtttc inPut・
lci1101γ
signtlis ill thct】 Or tO frcczc thc ilnage at the vidco(l to thc PrilltCn Thc Y・
R一Y・B一YC(111lPiliCllt Collncct(〕
vhilc
thc i11ltlgc(luality
ll10dcl htts tlll illtCrnlcditttc dtlttl
sizc,、is thc stllllC aS that()f thc ll(113 1110dcl.If the llnagc(lualities
1C・thC Stl:1lc,tllC lcss thc an10ullt ofdata,the bctten Tllerc‐tヽR)1・c,tllc Y R一 Y・ B―Y lllodel has thc best balance fOr cOn‐
1lS()
Stll11():・
・
1:llι
1｀
hc ttl110ullt ol・
lgc data ctin bc reduced ill t、vo/
Imagc Processor
・Ficld lntcrpolation:臨鷺i肥議愚m

F : G U R E l ―C
― ircuit block diagram.

′
OC‐
conlPrcss10:lP:・ヽヽhcll capturillg all i11lage,thc data―cstllC:11
Y
data
tlnd
stOl・
and
B―
cssor coinPrCSSes tllc Y,lt―ゝ
,.ll:(1(l:ll:1‑.V｀4)(::: 1)ri:ltinth(l il:1:tgく
ill:1ll ill::ιド(: !11(1:110:γ
C011lPreSSi01l PrOCessor〔StCPS・The lirst stcP is t0 11linilnizc thc llulnber of salllPIcs「hc sccond StCP is to CO11lPrCSS
orthc i:lPut Vi(leO sig:1:lls.・
dcgradation Of illlagc quanty
thc stlll11)lCd illltlgC .The
dtltt、
shOul(11)c tivoidcd in eitllcr stcp l)cct11lsC thC lluintln visualsystcnl is vcl1/critiCttl R)r stiH Pictures.
ヽrdS,tllc llunll)er()f ettctivc
Stt11ldを
Accor(lillg tO NTS(〕、 (1/‐1lo)is 485 and tlle cncctivc horizontal
vcrtictt! li11(ぅ(1)is 52.5 μs.1｀
1lC asPcct ratiO()f thc tclc‐r‐￨)()ri。
10(1(′PCl・ヽ「vi(lth to th(,th(,、
11(l t11く:tlio o「visioll ll:()llit()r(′)1ヽ1:13:ι
ハ′

lccolllPrcSSCS thc data ill thc illlttgc

ιt(lo1 0fthc l)rillter(rl,)is l:1.The llorizOntal dOt
height ol・lllemory and transfers thc data tO the ilnage processor.The
fl・c(11lcnCy of tllc
)isPrinter∝
dCterlllined to bc′
decolllPrcSSed ilnagc dilttl are also transferred to the vidcoI1011l thc lbHO、
ving cquatiOn:
A conlPICtC
interRIce fOr display on a television inonito■=(V― 0× ■・―/′
v()intcl・
ltlcc(lficI(ls in th(:1′ん
ilnagc,ctlHCd a rralll(1,collSiSts of t、
1,)/1′ PCri()(1・・NTSC Syst(,:ll.As thc l)rillt(lr cal)tl:rcs t、

12

int
:〕
lc,lISCl・S Ctll1 1)1・
11・
:ιTllc l)tin(lwidtll of tllc Y sigllal is 4.2 MIIz,anonc AcI(1.
tln illlagc fr011l cithcr thc c011lPICte )rfratllc《Y tt:l(l B―
Y signals ttre l.5 MHz. Thc Nycluist
Of thc ll一
The ilntlgc PrOccSSOr interpolates the field i11lagc all(1,vcvet a clockll・c(11lcnCyR)rthcYsignal is 8.4 MIIz; 1lo、
ヽ1enhanccs tllc sharlDnCSS and converts tlic Y,R一
if necessaDち
As a YIz is adOpted for sanlPling・
frc(11lency()F 12.3ⅣII―
11lle print‐ enginc PrOCCSSOr rC―
and B― Y data to cMY data。
signal sainPlcd at 12.3ⅣIIIz corresPonds to one dot ofthe
ceivcs thc Print data frO:n thc inlagc ProcessOr tl:ld colltrOls
illg circuit to convcrt thc salnPIed dOts,canprilltct thc riltcl・lancc of thc Picttirc t1lr01lgh tl thcrnltllnd grtly bュ
thc tonc t、tllc t()tal circuit c()1lStruCtl ) c l l c g l c c t c ( 1 , s i i nill)llgi ケ
hetld Tllc hcat encrgy gcncrtltc(l ttt thc t1lcr:1lt1l ll(,:t(l is
T
l
l
c
r
c
t
t
r
c
6
4
0
(
1
(
)
t
s
/
1
i
n
c with a 12.3‑M Hz sainPlillgvヽ
:):1lCthOd.
vidtll ll10(lLlliltioll(Pヽ、controHcd by thc Pulsc‐
Y and B一 Y signals, subsalnpling
thc Y signal. For the lt一( luartcr andvhich are Onc―fl・c(lucnciCS Of 3.l tind 6.2 MHz,、wcl・
c tcstcd.A digitalsPCCtiVclメ0 1 l C ‑ l l tol「1l 「2 3 M H z , : 。( 〕
3:rnage processing for the v:deo pr:nter｀( l t l t ao nrll ・
c
(
1
l
o
r
c
s
t
o
r
c
t lglicl lOl■
面
r
i
s
:
l
o
t
t
:
、
t
s
s
n
l
t
く
l ( ) w1‐、
3.l
Data reduction
一Y(ltttttl)cctlusc()f tllc circuit‖1)st、
1111)1('(111‑Y tlll(ll〕
tllc、
ncighl)Or(lttttl tlrc uscd to intcrPoltttc
CSt―
CO1111)l()xity. Nctll・
Y dtittl.VVhcll thc substl11lPlillg clock 6or tl
Y tlnd B一
thc il一
Y sigllals is 3.l MIIz,subsalllpling artifacts are
R一Y t11ld B一
vcvcち when tllc c10ck
llo、
casily R)und on Prillt salllPICS・
Y and B一 Y signals is
fl・c(lucncy R)r sul)st111lPling the R―

》漁
I∫
煎撫
鮒椰WttI島‖

111:電
1llぶ
嶺t:甘
l、
黒ilttI観:潔
1漁:i∬IIIz,thc ttrtillcts are ullobsclvablc evcn
turncd t11)to 6.2市
v―、
vitl10ut a lo、Pass filte■
dif‐Alllol18 11lany llllagc conlPression techni(lues,5thё
lbrcntittl Pulse COdC n10duliltioll(1)PCM)algOrithin、vas

adoptcd R)r thc Prilltcr l)ccausc of the foHowing reasolls.6
TABLE 2Comparも

l:lrHc::Ic(litttc
intel‐
s nla‖

lmago Qual‖y
簿 諄ｂ

llCI〕
Y I t ―Y 1 3 ‑ Y
C ( ) : l ol sl iぅt C
Vi(1(10

Dtlta Sizo

０´

Color ModelonЮ fてolormlЮdel,̲̲̲

idco l)l・illtet thc ilnage colllpression inustI「or the t・ls for a fralnc inlttge).
l)c d011c in rctll tinlc(33■:RIttt:『1‖ FI淵Of iintlgc.
(3)Tllc circuitッ for DPCM./imagC‐processing techniques for a consumer video printerκanο eftnノ朧￨1∬ ぶ rt鷲 樵
:

島
記
濡:c」
出 Ctl)thmnicoluhn(i‐1)th line Of fleld l f:.1,J.1
fl.1,Ji th line offleld lfl,J.1i th line of fleld 2

50
55

fl,J

f:̲1,J.:fl,":X(1+1)th line Of rlcld l fl.1,J.ュ fl.1,J

fl.1,』。
1(i+2)th line Of fleld l f̀●
2,J・
1 f:o2,J

fl●
●
2,」
1

―

F:GUR[3‑― A!ignment oF dOts.

H載
搬 Ⅲl 出
紺1 ヤ‖
富 e . h w ah bc hh り
『

つ ●I

̲

‑

Start

(b)
F:GURE2‑―

D l = l f : , , . ―f 1 , ´:￨
D 2 = l f : , j ―f 1 , 1 1
D3=l fi,″: ―f 卜1,1.:￨
D4=I Dl― D31

cOmparisOn of cOmpressiOn rates.
(See color sectiOn fO‖
Owin8 pa8e 120。

)「
igure2shOwsprintsillPle11:r」
1::∬
LIIIIII:』
:

r霧
ご
揖
‰鸞
辮
激
曲
:l1111‖也讐
i‖￨￨lltl 辮

一／Ｎ
一＼一slon mtes.Wllell all the x
ha1l nOisc and jitter are fOund a10ng thc
PreSSed t0 0ne‐

D4

∬
醤
∬
鮮
ぶ
躙鶉
赫華惚警鶯
il‖

el1701pute,uゎ
品nt Yledl°
hI
中
ζ
揺
苗
∬
:fT議
∬‖
よ
:よ
」 Cttu ai nnttgc話

織ilf器
群驚I胤1ぶLce in the printeL TheSe Lcts illean that the DPCM algO̲ヽinter can1lot bc cttsily sc(,11.

diffcrences
the thesainl)lingc .惚 SalnPling
ffCtncesof of
samメ
ing
1選
dOcks.
:選ぶi11霊clock 癬Of中

X=〔 1,"1+f :,j.:p/2
Ｎ〕ffcrc5耐¨ 鳳 hh品

X=(ft,:+f":,lp/2

D

X=(f:,J・:+fl.1,J◆,p/2
N

F:GURE 4‑‑3DS:a180rithm.

journa!oFthe SiD′
1/1′1993・::■∵
Ч:τ ・■11:1■ ・｀・
三:・ヽ:jl.￨‐̲ ・ 1■‐
1: ■. r i.::1:=111:: 「■:̀1サi)洋 1111■, ¨:.■.￨:、
・
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…γ
::●
:IⅢ:l iJll.11:l「'1」
1lII'IT年,…
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:1.・

il:11

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ludon

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X.

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l l l lヽゝ̲SNRdB】 20〔￨●r
nearest ri3h●

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ヽ
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ヽ
160

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200

11電

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240

TV‐:h

F:GUR[ 6 ‑ Spatial frequcncy characteristics of interpolation
algOrithms

thc cOllvcllti01ltll systel11, thc valuc Of■
is tlle saine as thc
vttitic Of tlle llctlrcst dot(ncarcst‐
1lcighbOr intcrPOlation),Or()f thc vtllll()s()1・
vcr dOts(l)i‐
tllc tiv()rttg(〕
thc lIPPcr tllld 10、lill(■ll・illt(,ド
itllllls tlrC Silllplc,but thc
1)olati011).Thcsc tllg()1・rcsultillg(luality is also lilnited.Stllave deve10ped a lnOres01)llistictltcd algOritlllll that is acccPtal)IC witllin the sP
lilllittltions fcDr thc PrinteL TllC tilnc PCrinittcd fOr the inter̲

oln tlle following
μs/dOt fl・P()lttti()11(亀̀)is found to l)c65.l()(111:ltioll:ι
i"̀=P― tilne/dot― nO.

(2)Here,P‐time is tile real print time for each c010r
including PtlPc卜
feed tilnc,etc.)and is abOut 10 s in thisnO
Printer;dot― is thc tOtal number Of dOts in a field iinage
and 640× 240 in thc PrilltCr.
Tllis Acld illtcrPohtiOn[3 dircctiOns selcctive intcrPO‐
vcen
ltltiOn(3:)S:)]ttlkcs illto ttccount thc correlatiOn bc■
vhich thediagonal dOts. Irigure 4 shows this algorithln,in、(b)va1110 0f■is dcterlllined to bc thc average of the llighest
F:GUR[5‑― Comparison ofintcrpolation a180rlthms.
correltttillg Pair of dOts alnong the thrcc PairS Of dOts thatc.Tllc varial)lcsメ,,̲トメ,′
stuldwicll tllc(1()t■(SCC CO10r scction lollowin3 page 1 20.)
,メ,ノ
+1'Ctc.,al・thc(10ts sll()wn in「ig.3.Thc cOnsttint TFr is a
thc vtJtics 01｀,s1101(lv:lllic tO(1(,t():・
vhctllcr thcrc is tl distillctivc
1llilic、
thrく
110t.″「
cliagolltll
C(lgc
ol・
hc
31)SI
PrOVi(lcs the sainc results for
3.2 Field:nterpolation
hOrizontal and vertical cdgcs as bi̲lincar interPOlatiOn,but′ヽヽ1lcn tl stiH Picturc is takcll frO111 1110Ving Picturcs, thc
illterPolates thc diagOnal edges lnOre smootllly.As shown in
capturcd franlc nickcrs oll tllc lllollitor bccausc etlch ficld(ヽ1。
1 lt ti:ll(l ill tllc 33‑:1ls illtClvtll￨卜
c ttt a(lil｀Ctll)tl:rcs tl PiCtlH・t l:l1、C1 llcl ・( ) 11)))r′( ) ( 1 l l c(c)(:1l1i1 ・l i l l g l ) t 1 t1 l:(ltl(lC〕
i′
csr、
)′
・
A c c o l(・is uscd to prillt ill this ctlsc
dcgradcd.C)1lc()r tllc v。llcI(lst、
atln(l thc Otllcr ficld is illtcrpOLltc(l frOin the sclcctc(l ficl(l t0
thc dot arrtlngc̲
tllllc. Irigtlrc 3 vssho、
:ntlkc a cOinplctc li・n l c l l t o f t l l c t w ( ) A c l ( l s . T l l c A ( ) ￨ l( al t i (l 】
l it sc r Ll I) S。C d t OXCbl thc vttitics()1'thC
ol〕
■ 111
1ヽ
ctllcultltc thc vtllllc
O「 lrig. 3・()tl ll(ling(lots()f t1lc
Otl、
cr ficl(1.
stirl。
[ h(: 11(:￨(l :‐i:lt(ヽ
νl、
1・itlllll、
11)l・
ioHs ttlgO:・
Polttti011 11ttvc
d
1)s。
7‐
,v()lligh illlttg()(1llalitメ:1lc ol・
tllc11l tlChiくl)ccll OPOSC(1・Pl・
vitllill tllc lilllitatiolls()1・
but thcy arc too cOlllplcx t0 11scヽ
ln F:GURE 7‑Dot arrangemeni for edge enhancement.
th(〕constinlcr vidco 1lltcll
Pl・
C011lputillg ti11lc t11ld)rCOst長

100Ka′ ,O ertl′/lnlogo―￨)roCCSSin3 techniques for a consumer video printcr

1,■
￨ザ
ド1・
準
T'・iF:■

ノ ′(1)The printerヽ cMY are nOtthe perfect cOmplemen―tary colors tO the NTSCヽ
1lCB.
(2)An television inonitors are not in a standard
C ( ) 1 1 ( l i t i.( ) 1 、
IIcncc, c010r cOnvcrsi01l frO:ll NTSCヽ
printcrヽ

convers10n is perFc・

C,M,Y topnnt cnginc
F : G U R E 8 ‑ ‑ 3 ! o c k d i a g r a m o F i m qa ug ae :‐l t y a d i u s t m e n t p a r t .

ll(:l〕to the(′
YM is tl non‐ lillcar cOnVcrsiOn. Evcll though thc
ct, the rcPrOduCCd llard cOPies do nOt

nccessarily inatch the inOnitorヽ
colors.Accordingl)ιwelnly
necd several trials tO get a satishctOry colly.
The inltlge prOcessor of the videO Printcr uscs thefOll()willg cqtlatiolls wilcn c01lvertillg、R―ヽ and B―Y datatO CMY data:
C = L l ― K H ・Y t t K 1(2R・D + K 1 3 ・ ( B り'

Fig.5,the reproductiOn print of a tOmato by 3DSI iS inore
M=L2 K21・ γ+亀 2・(R―D+43・ (B り , (6)natural than that by l)i̲lincar inte,PolatiOn.
Figure 6 shows the sPatial frc(luency characteristics of
y=L3 K31・γ+K32・(R―η +穐 (3‑η .
3・
the 3DSI(TH=0),nearest― neighbor interlDolatiOn,bi―lincarinterPOlatiOn,and cllbic c01lv011ltiOn intc:・(〕
PolatiOn.(〕irclll:lr
As!o:lg tls tll(,Nl・ヽ｀Prilll:liγ
s tti・
Ct:SC(1:til(l tliC
C()101・z()nc PlatcS Of IIxcd IIc(lucllCヌ
dcscribcd in E(1.(3),wcrc
(】
MY
arc
thc
Pcrfect
cOlllPle:nentarycolors of the
Printerヽ
used tO lneasure the signal̲tO̲nOise ratio(sNR)。
NTSCヽ1ヽ
c B,Ll,L2,L3,K11,K12,K13,K21,K22,K23,K31,K32,

・(■2+y2/4801・Z←,y)=68 x cos(π∫+π)+138.

( ‑ 3 2 0 ≦■≦ 3 2 0 , ‑ 2 4 0 ≦y ≦ 2 4 o ( 3 )、■ng forinula:
SNR iS defined by the folloヽ

2/Power)・(err。
SIVR=10×
b&o(Σ
14)
→

and K33 are 255,255,255,1,1,0,1,‑0.508,‑0.186,1,0,1,
reSPeCtiVely. But these cOnstants are shghtly modified toilnPrOVC the rcl)rOducti01l of skill tOncs and tO increase thec010r saturation.
Onc Of thc illlPOrtant features of this videO Printeri s t l l a t t h e u s e r c a n e a s i l y a d i u s t t h e t ic nO tn ,t cr 0a 1s 0t ■,and luminance after capturing an image while observing
Here, an error is the difference beぃween the truet h e a d i u s t e d i m a g e O n a t d e voin●m O n t t o n W i t h o u t t h i svaluc and the interPolated value.3DSI iS the best inte,Pola‐ featllre,1lsers wotll(1vc 1lι
t0 11lllke rCPctlted tritlls un(、
wcr than 130 Tv lines and bctwecll
tion when there are rc・diffcrcnt Print conditiOns to ol)tain satisfactOry repro
250 and 270 Tv lilles,and bcttcr tht11lhncar
bi― intellDOlati011
ductiOn.
fOr aH bandwidths less than 270 Tv lilles.
Figure 8 shows tlle b10ck diagram of tllis adiustment

3.3

ThC Output Ofthc attustm e n t v d u m e s ( cPart・Edge enhancement

bOth an anal()gaclillstn]cllt circllit alld a micrOProccSSOL Tlle

The pl・inted image is sharpened by the fOHOwillg ildaPtive
filtcr:

・
(2・
(2・
■―わ―ε
LctOr=α■―α―ご) + β・),if(I LCtOr l>threshOld),■else■ =■ ,ana10g aclillStmcllt circllit nl()(lincs tllc inltlgc On a tclcvisi()ntl1011it01・.ヽヽアll(,:11):・
inti:lg,tllc llliC:・ 01)1・
oCCSSOr rCil(ls thc l)Osi―
tiolls 01・ thc cOntrOls thrOugh its alla10g―

tO―digital(A/D)POrtS

a n d s c t s t h e L i t a n d ta t te tv Oa l tu he es . aT phadiuStinellt,color adiustment,contrast adiuStmellt,and lu―
minance adiuStinent corresPOnd tO the rOtatiOn of the=■ +LCtOr(5)

chr011111lancc,gtli:l contl・ol of thc chrOlllintlncc,gain cOntrol
Of the lulllinance,and the 01lsct cOntr01 of the luminance,
rcspectively.A satisf・
actOlyprillt can easilybe obtained using
this featurc.

where α is thc К rticJ edr― enhanccment coeffident,βおenhancement coefficient,the threshOld
the hOrizOntal edge‐
is a constant,and the dot arrangement of■, ,b,c,and d isshown in Fig. 7. This adaptive filter cnhances Only tllc
distinct市
e edges but dOes nOt amplify low̲amPlitude nOisc 4 C o n c l u s i O n
C01nPOnents.
The systelll configuration and illlage―
ProceSSing techniques
vly devc10Ped videO Prillter produce good ilnage
fOr the nc、

3.4

Color conversion

0111
There are two prob!ems fOr cOnsumer宙 dco prilltcrs fl・
the standPOint Of c010r rcPrOduction:

quality and alsO cOntribute tO case of oPcratiOn and cOln‐
Thcsc lcaturcs will enlarge thc inar―
PaCtnCSS OFc(llliPnlcllt・
ket fOr cOllsulner vidcO Prillters.

,Ourna:ofthe SiD′1/1,1993

101

・
｀
'｀｀
1〜 ・・ ｀ ..‐‐・
・
̀・
: ̀'・

Hidoolo Fuiita received his B.E.and M.[

ハcknοwredgmenf

degrees in instrumentation engineering frOm

ノ″

V/e、vOuldliketothtlnktheinembersOftllcAVdcvc10Pincllt
center and the vidc0 111anuFacturing divislon for theil・
hclP
ill dcvc10Ping tllc vi(lco l)rilltc■

ReFererlces

Kobe∪niversit" Kobe,lapan′ in 1985 and1987′ respective!y :n 1987 he ioined theControl and systcms Rcsearch CenteL Sanyo
Elcctric cO′Lid., Osaka, lapan, where hehas been engaged in research and develop‐̲・l Ha:lma ι ′A Color Vi(lcO Pri:lter with Slll)liln:tti()nl)yc Tnl:lsrc:r,・̀″
Mct110d,''IEEE
Tr̀=,Is ,,I,●
Cで ,':ιr E′ιοι ,,iCE‐31,431‑486(1985)
・
2′Rt:clliyを
lιι″J,・
New C()lor Vi(1001)rinti:lg Systcllls,"rEEE lhは,ls(′,,is"″で:ιr″′″,,:(〕
Cr′
E‐35,352‑359(1989)

3爛
冠准
触
1.ぶ
蹴
胤1蹴
常
蹴踊加棚∴
1脇￨
#嚇I:X傷Kiγoshi Fukushima received his B.E. de8ree

4 0no a″′, T l l e c O n l P a r i S O n o f l ) i c t u r c Q l l a i n i c s 0 1 l T e l e V i s i1く
1)()―
":、
"f=EJ″
togrtlPlly alld IIard̲COPメ,,″':43,No.10,929‑937(1989)

in precision engineerin8 from Kyoto Univer‐5 1 1 t t r a s i l i,n lI ■ntⅢ
o ( l u c t i O n t O 1 1 1 1 : l g c D a t t i C o i n P r e S S k ) n : ( 1】
)11‑3 t i s i c ( ■C e l ) t S O f l m a g e D a t a C o n l P rOenS,」" f r E ノ ″′ 4 3 , N o 6 , 6 ( ) 3 ‑ 6 1 2(1989).
6 JoncsC・t ar, DigitaHlll、ge ColnPrcsJOn,¨ SrD Sο
r Jx・r̀ rc・
A7r'fい,"::"′M‐2(1991).
71)ratt,Digit″ ′r, ″g″P ,c‐si,lg(ヽVi!eメ New■ )rk,1978).1, 113.
.A New 11lte■
8 Miyake σ ′)('latiO:l Mctilo(10「Tc・l(,visì):l Pictl:rく,・'sl)r
̀″l)rintillg Systcllls,"ノColl、lct
r,,I″
gj′
tg 7し
cra 14,N()4,95‑99(1988)

Pを931)● 1(1lìィ″′. ¨ l n i P) V ( : ●X ｀1 l t O 「 V i ( 1 ■ ) I l a r ( l ( ・( 1 ) y I I n a g ( ・ 0 1 1 ・l l i t y b y(′′′Usilig SPlillt:1::t(.:1)●
l:lliOl〕′
だ′′
イル′
1).N0 7, 127̀,―,"71 rr"、
′
̀′
̀J71‐
1285(1988).

∬ h

Sanyo Electric Co′ Ltd.′Osaka′ ,apan,
where he is a manager in the Control andgaged in resoarch and dcvelopment Of color
printing′
crysta! TM and cOntrOl sys‐liquid‐tems.ML Fukushima is a member Of The la―nn(l￨)Inn SOCiCty of M(lchanical Enilinoors
・:hc !nstittllc t)f l:lit18C・
Llc・
ctrOnics L:181:lCCrs of lal)anUniversity Kyoto′,apan, in 1982 and 1984′
respectively !n 1984 he ioinCd thc Control
and Systems Rcscarch CenteL Sanyo [lcctric
Co.′Lid.′
Ostlka′,apan, Whcre hc has l)ccn
en3aged in research and developmen1 0f
color printing and color image processin3・
Mn Kano is a member Of The institute ofElectrOnics′
information′
and Comnlunica‐
tions Engineers of lapan and the infOrmation PrOcessing Socicty oF,tapanKanοsity Kyoto′lapan′in 1969 and ,Oined

Systems Research Centen He has been en‐

HirOshi Kano roceived his 3.E and M.[ de―grees in information en8inOOring frOm KyOtO

102

menl of cO10r printing and cOlor image proc̲
ess:ngef a′/image‐ prOcessing techniques fOr a consumer video printer

Kazoo :to received his B.E. degree in elec‐
tronics enginccrin8 from Nagoya :nstitute of
TcSchnolo8y7 Nagoya, lapan′ in 1970. :n1970 hc ioincd sanyo [lcctric CO.′ Lid.′
Osaka′ lapan′Where he is a manager at theA∨ Dcvelopment center.ML ito has been
engaged in research and deveiopment Of
video printers, optica! video‐
disc players′
and iaser pickup for compact discs.