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.