Prin, you've got a bit of a problem there :-) ----- Original Message ----- From: "Prinyar Boon" <Prinyar.Boon@xxxxxxxxxxxxxxx> To: "opendtv (freelists)" <opendtv@xxxxxxxxxxxxx> Sent: Friday, January 14, 2005 1:34 PM Subject: [opendtv] RGB Mainia -try again > OK=20-=20try=20again, > > The=20problem=20we=20have=20run=20into=20in=20the=20TV=20world=20is=20the=20 = > interpretation=20of > the=20coding=20range=20-=20specifically=20the=20"meaning"=20of=20black=20a= > nd=20white.=20=20This > is=20something=20that=20Alan=20and=20I=20have=20kicked=20around...Take=20t= > he=20meaning=20of > 'white' > > In=20an=208=20bit=20ITU-R=20BT.601=20system=20the=20code=20for=20'white'=20= > is=20235=20[decimal]=20- > all=20seems=20clear=20and=20simple. > > However=20-=20if=20you=20look=20at=20the=20taking=20characteristics=20of=20= > the=20camera=20-=20and > specifcally=20its=20optoelectronic=20transfer=20function:=20there=20are=20= > at=20least=202 > meanings=20of=20white.=20=20The=20first=20is=20established=20by=20the=20kn= > ee,=20the=20second=20is > the=20area=20which=20is=20used=20to=20cope=20with=20specular=20highlights.= > =20=20The=20position > of=20the=20knee=20-=20and=20the=20slope=20of=20the=20compression=20for=20h= > ighlights=20are=20both > under=20control=20of=20the=20camera=20man. > > So=20what=20do=20you=20do?=20Do=20you=20set=20the=20knee=20[I'll=20call=20= > this=20the=20mid=20to=20large > area=20white]=20for=20235,=20and=20allow=20speculars=20to=20go=20up=20to=20= > the=20link=20clip > limit.=20=20Or=20do=20you=20set=20the=20speculars=20for=20235?....or=20do=20 = > you=20make=20them=20both > the=20same? > > At=20the=20display=20end,=20a=20conventional=20TV=20[not=20a=20broadcast=20= > monitor]=20-=20will > allow=20the=20small=20area=20luminance=20level=20to=20reach=20say=20450cd/= > m2.=20=20However=20the > large=20area=20light=20output=20will=20be=20limited=20to=20say=20120cd/m2.= > =20=20So=20a=20tellie=20- > as=20the=20ability=20to=20have=20a=20stab=20at=20reproducing=20specular=20= > highlights.....and > does=20this=20by=20the=20miracle=20of=20beam=20current=20limiting.=20=20It= > =20also=20manges=20to > interpret=20small=20areas=20of=20code=20235=20as=20specular.=20=20This=20i= > s=20probably=20a=20good > thing. > > Now=20-=20you=20try=20doing=20that=20on=20either=20a=20PWM=20based=20or=20= > light=20valve=20display. > Interestingly=20a=20plasma=20panel=20does=20have=20a=20related=20small/lar= > ge=20area=20white > characteristc=20-=20based=20on=20overall=20power=20limiting,=20and=20Panas= > onic=20have > engineered=20some=20dynamic=20APL=20based=20processing=20into=20their=20pr= > ofessional > projectors.=20=20However=20this=20combination/mixed=20melange=20of=20displ= > ay > characteristics=20in=20the=20field=20just=20makes=20things=20even=20worse,= > =20we=20have=20NO > chance=20of=20achieving=20a=20controlled=20transfer=20between=20broadcast=20 = > monitoring > and=20home=20viewing. > > In=20addition=20to=20this=20-=20because=20BT.601=20does=20not=20distinguis= > h=20between > specular=20highlights=20and=20medium/large=20area=20white...we=20do=20not=20 = > have=20any > simple=20mechanism=20to=20signal=20to=20the=20display=20that=20this=20is=20= > a=20specular > region...which=20has=20had=20this=20compression=20slope=20applied=20by=20t= > he=20camera.=20=20To > compound=20matters=20-=20if=20you=20even=20tried=20to=20use=20this=20specu= > lar=20region=20then=20a) > Some=20alarm=20in=20some=20gamut=20legaliser=20would=20trigger=20and=20som= > eone=20would=20wind > in=20the=20clippers.=20And/Or=20b)=20BECAUSE=20we=20did=20not=20codify=20t= > he=20the=20use=20of=20this > region,=20and=20because=20we=20did=20not=20say=20that=20all=20digital=20di= > splays=20should=20have > a=20soft=20clipper......then...if=20the=20broadcaster=20did=20not=20apply=20 = > the=20soft > clipper=20-=20the=20display=20would=20probably=20hard=20clip=20-=20which=20= > would=20be=20even > worse. > > So=20-=20this=20is=20a=20subtle=20and=20unintended=20consequence=20which=20= > is=20due=20to=20a > simplistic=20interpretation=20of=20the=20coding=20range=20[based=20on=20wh= > at=20worked=20for > CRT's]=20and=20the=20switch=20to=20digital=20matrix=20displays. > > The=20whites=20are=20relatively=20straight=20forward=20to=20explain! > > Television=20is=20just=20plain=20broke... > > Prin > > Prinyar=20Boon > Snell=20&=20Wilcox=20Ltd > Liss=20Mill > GU33=207BD > > email:=20prinyar.boon@xxxxxxxxxxxxxxx > Tel:=20+44=20(0)2392=20489=20280=20direct > Fax:=20+44=20(0)1730=20894=20341 > www.snellwilcox.com > > -----Original=20Message----- > From:=20opendtv-bounce@xxxxxxxxxxxxx=20[mailto:opendtv-bounce@xxxxxxxxxxxx= > g] > On=20Behalf=20Of=20Alan=20Roberts > Sent:=2014=20January=202005=2012:16 > To:=20opendtv@xxxxxxxxxxxxx > Subject:=20[opendtv]=20Re:=20RGB=20mania > > Not=20quite=20right=20Jeroen.=20=20ITU.601=20etc=20all=20include=20specifi= > cations=20for=20the > coding=20of=20RGB=20as=20well=20as=20YUV=20signals.=20They=20form=20a=20cl= > osed=20set.=20The=20rules > for=20Y=20also=20apply=20to=20RGB.=20Indeed,=20the=20coding=20of=20YUV=20c= > omes=20from=20a=20digital > calculation=20using=20digital=20RGB=20signals,=20each=20of=20which=20must=20 = > conform=20to=20601 > coding=20rules.=20At=20no=20point=20is=20there=20any=20flexibility=20in=20= > the=20coding=20of=20Y, > since=20it=20normally=20doesn't=20exist=20in=20analogue=20these=20days. > > The=20headroom=20in=20the=20coding=20range=20is=20specifically=20for=20the= > =20RGB=20signals > rather=20than=20Y,=20the=20extra=20range=20that=20Y=20has=20as=20a=20resul= > t=20is=20almost > accidental. > > Alan > > -----=20Original=20Message=20----- > From:=20<jeroen.stessen@xxxxxxxxxxx> > To:=20<opendtv@xxxxxxxxxxxxx> > Sent:=20Friday,=20January=2014,=202005=2011:51=20AM > Subject:=20[opendtv]=20Re:=20RGB=20mania > > > >=20Hello, > >=203. > >=20With=20digital=20RGB=20"graphics"=20signals=20(e.g.=20DVI=20out)=20it=20 = > is=20common=20to=20 > >=20have=20black=20=3D=200,=20white=20=3D=20255,=20but=20with=20digital=20= > YUV=20"video" > >=20signals=20(e.g.=20ITU-R.656=20or=20SDI)=20it=20is=20common=20to=20have= > =20black=20=3D=2016,=20white > > >=20=3D=20235.=20The=20Y=20signal=20has=20headroom=20that=20the=20RGB=20si= > gnals=20have=20not.=20This=20 > >=20headroom=20is=20reserved=20for=20the=20ringing=20due=20to=20anti- > > >=20Greetings, > >=20--=20Jeroen > > Prinyar=20Boon > Snell=20&=20Wilcox=20Ltd > Liss=20Mill > GU33=207BD > > email:=20prinyar.boon@xxxxxxxxxxxxxxx > Tel:=20+44=20(0)2392=20489=20280=20direct > Fax:=20+44=20(0)1730=20894=20341 > www.snellwilcox.com > > This=20email=20and=20any=20attachments=20is=20confidential,=20may=20be=20l= > egally=20privileged=20and=20is=20intended=20for=20the=20use=20of=20the=20a= > ddressee=20only.=20If=20you=20are=20not=20the=20intended=20recipient,=20pl= > ease=20note=20that=20any=20use,=20disclosure,=20printing=20or=20copying=20= > of=20this=20email=20is=20strictly=20prohibited=20and=20may=20be=20unlawful= > .=20If=20received=20in=20error,=20please=20delete=20this=20email=20and=20a= > ny=20attachments=20and=20confirm=20this=20to=20the=20sender. > > > ---------------------------------------------------------------------- > You can UNSUBSCRIBE from the OpenDTV list in two ways: > > - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org > > - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line. > > ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.