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Gordon Burditt
Guest
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 Posted:
Fri Oct 29, 2004 5:28 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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| Quote: | Apparently the Europeans have been brainwashed. It's
apparently a congenital ability, bred into them
during the 20th century.
God, you're just as fucking arrogant and ignorant as Dyson.
They have had it repeated that PAL is superior
so many time ... for one and only onme obsolete reason ...
that they actually believe it.
|
Is this a genetic or environmental issue?
Europeans see in colour. Americans see in color. While most natural
objects have approximately the same color as colour, this is not
true of certain cheap inkjet printer inks, and I don't know what
the situation is with CRT phosphors.
The exceptions make possible things like the joke T-shirt which
will be seen by Americans as red-on-black saying "God save the
Queen" and which will be seen by Europeans as green-on-white saying
"God <bleep> the Queen", thereby making it likely that the person
wearing it will get beaten up by both sides.
| Quote: | You never actually seem to define what this 'decodable' means.
My TV decodes PAL into R, G and B just fine. There will always be
cross-luminance and cross colour (assuming that's what you are
talking about) whatever the system. The actual hue of the colours
will NEVER NEVER EVER be wrong on PAL. It will be on NTSC. This is
the point. Do you get it?
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Does anyone have the formula for converting red color, green color, and
blue color images to red colour, green colour, and blue colour images?
Gordon L. Burditt
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Sal M. Onella
Guest
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| Posted:
Fri Oct 29, 2004 6:46 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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"Paul Ratcliffe" <abuse@orac12.clara34.co56.uk78> wrote in message
news:slrnco2tca.c5i.abuse@news.pr.network...
| Quote: | On Mon, 18 Oct 2004 00:14:28 +0000 (UTC), John S. Dyson <toor@iquest.net
wrote:
All the crap about chromaticity is waffle designed to confuse the
ignorant
reader.
If a 'very good green' isn't in your gamut, you cannot display it. The
'Green' in the NTSC gamut is certainly better. It seems like you are
talking beyond your competency. Just because there is a too-complex
idea for you, this doesn't mean that the idea is wrong.
You fucking arrogant little shit. Typical attitude of a lot of Yanks.
And you wonder why the world wants to blow you up?
|
.... er, why would anybody want to read past here?
Your pal, Sal |
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John S. Dyson
Guest
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| Posted:
Fri Oct 29, 2004 12:51 pm Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <slrnco2tca.c5i.abuse@news.pr.network>,
Paul Ratcliffe <abuse@orac12.clara34.co56.uk78> writes:
| Quote: | On Mon, 18 Oct 2004 00:14:28 +0000 (UTC), John S. Dyson <toor@iquest.net
wrote:
All the crap about chromaticity is waffle designed to confuse the ignorant
reader.
If a 'very good green' isn't in your gamut, you cannot display it. The
'Green' in the NTSC gamut is certainly better. It seems like you are
talking beyond your competency. Just because there is a too-complex
idea for you, this doesn't mean that the idea is wrong.
You f*cking arrogant little sh*t. Typical attitude of a lot of Yanks.
And you wonder why the world wants to blow you up?
You are the person who brings of the issue of 'ignorance.' I simply provide |
a mirror for you to see it. The UKers who just met me a few weeks ago
in the UK wouldn't likely have deemed me arrogant, but I do have a bit
of transparent honesty that can sometimes be unpleasant. When you look
at those who wish to 'blow us up', you'll also mostly see cases of extreme
ignorance who sometimes have just enough technical knowledge to cause serious
damage.
Using low-class language isn't really appropriate in technical discussion
either.
John |
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Doug McDonald
Guest
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| Posted:
Fri Oct 29, 2004 7:10 pm Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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Paul Ratcliffe wrote:
se?
| Quote: |
The fact is, NTSC is completely decodeable at the
consumer level, while PAL is apparently only decodeable
You never actually seem to define what this 'decodable' means.
My TV decodes PAL into R, G and B just fine.
|
Uh, no. It decodes the DC COMPONENT.
| Quote: | There will always be
cross-luminance and cross colour (assuming that's what you are
talking about) whatever the system.
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Uhh, NO ... in NTSC. And that is the point.
What decodeable means in this context is that one
can retrieve the original luma and chroma from
a composite signal without crosstalk. Because
of the simple phase structure of NTSC, the
3D decoders in consumers sets do a truly excellent
job of this decoding.
Doug McDonald |
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Pete Fraser
Guest
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| Posted:
Fri Oct 29, 2004 7:40 pm Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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"Doug McDonald" <mcdonald@SnPoAM_scs.uiuc.edu> wrote in message
news:cltmh7$de0$1@news.ks.uiuc.edu...
| Quote: | Because
of the simple phase structure of NTSC, the
3D decoders in consumers sets do a truly excellent
job of this decoding.
|
That's not really true. The simple phase structure in NTSC
makes things easier, but there are techniques for dealing
with 90 degree phase shifts and incorrect V-switch sense in PAL.
I think it will probably be a couple of years before somebody
has a decent (verging on excellent) motion compensated
3D decoder, and it will be easier to build for NSTC than
for PAL, but not hugely so. |
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Gareth Rowlands
Guest
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| Posted:
Fri Oct 29, 2004 8:42 pm Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In message <clted0$2743$3@news.iquest.net>
John S. Dyson wrote:
| Quote: | When you look at those who wish to 'blow us up', you'll also mostly see
cases of extreme ignorance who sometimes have just enough technical
knowledge to cause serious damage.
|
I'd quite agree with that.
In this thread there has often been a marked lack of awareness:
1) Of the distinction between electrical and optical gamut.
2) That there is no longer a tie between display colourimetry and any
Television Standard of the same name
3) That the current day display colorimetry of TV sets in the US is
generally speaking, extremely close to the display colourimetry of
TV sets in Europe.
4) Of existing and widely understood technical terms when vague and woolly
ones will do.
5) That 50Hz interlaced display is not the problem for accustomed European
viewers that it is for those used to 60Hz.
Out of interest, does any reader know in which decade US manufacturers
stopped fitting tubes with 1953 NTSC primaries to their sets ?
Cheers,
Gareth.
--
http://www.rat.org.uk gareth at lightfox dot plus dot com |
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John S. Dyson
Guest
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| Posted:
Fri Oct 29, 2004 11:19 pm Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <634e8e054d.news@lightfox.plus.com>,
Gareth Rowlands <gareth.see_sig_block@127.0.0.1> writes:
| Quote: | In message <clted0$2743$3@news.iquest.net
John S. Dyson wrote:
When you look at those who wish to 'blow us up', you'll also mostly see
cases of extreme ignorance who sometimes have just enough technical
knowledge to cause serious damage.
I'd quite agree with that.
In this thread there has often been a marked lack of awareness:
1) Of the distinction between electrical and optical gamut.
Actually, I have been fully aware of the lack of optical gamut on |
many kinds of consumer grade display devices. It is interesting
that alot of people are stuck-up thinking about phosphors, when
many common devices don't use phosphors nowadays. The resultant gamut
is based upon the limits of the various processes and devices, and
PAL does impose such a limit, but so do low end (too-common)
CRT phosphors.
| Quote: |
2) That there is no longer a tie between display colourimetry and any
Television Standard of the same name
The amazing thing is that NTSC can/does provide the wider gamut (per |
my high end video equipment.) Just because a phosphor (mostly legacy)
based display doesn't reach as far into the green color, that doesn't
condemn all phosphor or filter based displays...
| Quote: |
3) That the current day display colorimetry of TV sets in the US is
generally speaking, extremely close to the display colourimetry of
TV sets in Europe.
Are you speaking of the limited gamut of cheap phosphors, or the wider |
possible gamut of filtered color (along with a TV system that can provide
the wider gamut?) Geesh, a high quality SMPTE phosphor can reproduce the
limited PAL gamut just fine.
| Quote: |
4) Of existing and widely understood technical terms when vague and woolly
ones will do.
Which ones are those? There are definitely differences in terminology |
across the pond. For example, the patent that I heard about was a
PAL decoder, but the patent that I read was a chroma demodulator.
| Quote: |
5) That 50Hz interlaced display is not the problem for accustomed European
viewers that it is for those used to 60Hz.
This is obviously why 100Hz TVs even resided in my hotel rooms? Note also |
that in the case of naive viewers, 60Hz tends not to be nearly as flickery
as 50Hz -- but once you become used to the flicker, that only mitigates
the perception of the flicker itself, but other side-defects will still
persist... In a similar way that both PAL and NTSC can be advantaged
by using the best available comb filter, 100Hz can improve the problematical
50Hz vertical scan rates.
| Quote: |
Out of interest, does any reader know in which decade US manufacturers
stopped fitting tubes with 1953 NTSC primaries to their sets ?
Remember, high end TV sets in the US tend not to use phosphors at all. High |
end TV sets in the US tend to be larger, and the perception of sharpness
is more difficult to attain without evil tricks. It is quite possible
that a 20inch PAL TV with OTA signal will look sharper than a 38"
display of a component NTSC scan rate signal, and naive viewers will
not realize the fact that the differences in the screen size can play
tricks.
And finally -- PAL is still not nearly fully decoded in the consumer
(and even most often in the professional environment.) I was amazed
to see the cross color on the DTV broadcast (equivalent to a low end
NTSC decoder in quality.) Admittedly, in the US, there are TV stations (and
even networks) that sometimes use low end decoders, but at least there
is the commonly accessable choice to fully decode NTSC.
I was really disappointed to see the BBC chroma demod to have the limitations
that it does have *unless it is used in combination with a 3D decoder.
John |
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John S. Dyson
Guest
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| Posted:
Fri Oct 29, 2004 11:22 pm Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <slrnco2tla.c5i.abuse@news.pr.network>,
Paul Ratcliffe <abuse@orac12.clara34.co56.uk78> writes:
| Quote: | On Wed, 20 Oct 2004 11:29:31 -0500, Doug McDonald
mcdonald@SnPoAM_scs.uiuc.edu> wrote:
Apparently the Europeans have been brainwashed. It's
apparently a congenital ability, bred into them
during the 20th century.
God, you're just as f*cking arrogant and ignorant as Dyson.
Speaking of true facts shouldn't irritate you so much. You |
have too much invested into PAL hype. Fully decoded PAL
would probably look really good, but you cannot see it.
(Even the BBC decoder has some limitations, that would just
not be applicable to a proper 3D NTSC decoder.)
John |
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John S. Dyson
Guest
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| Posted:
Fri Oct 29, 2004 11:25 pm Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <27f1d4f3.0410211501.288a5e6f@posting.google.com>,
100246.2055@compuserve.com (Ian Mackenzie) writes:
| Quote: | John Dyson wrote:
The bottom line: it cannot be 3D decoded in the home, and that
is sad, because it would have significantly improved the analog OTA image
quality. If the NTSC color encoding techniques and gamut were generally
used (instead of PAL encoding), you'd see little or no difference on
an A/B comparison, unless you would use a full 3D decoder (not likely
for PAL) and/or have full gamut NTSC phosphors.
It is not unlikely, many "Home" PAL TVs in Australia actually have a
true
comb 3d decoder and give the same results as NTSC.
If Australia has PAL, then it doesn't fully decode the signal like NTSC |
decoders can. You might be thinking about a 3 line comb. Lately, for
PAL, 5 line combs are also used (which can be used in conjunection with
3D processing that is specific for NTSC.)
The problem with 3D combing isn't that you cannot do it for PAL, but the
results would be useless without MUCH MUCH more processing.
John |
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John S. Dyson
Guest
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| Posted:
Sat Oct 30, 2004 2:59 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <10o5l1q6qsr0119@news.supernews.com>,
"Pete Fraser" <pete@rgb.com> writes:
| Quote: |
"John S. Dyson" <toor@iquest.net> wrote in message
news:clujh4$2hs2$3@news.iquest.net...
The problem with 3D combing isn't that you cannot do it for PAL, but the
results would be useless without MUCH MUCH more processing.
You keep saying this, but never explain.
Nor do you answer any of my posts that indicate that 3D decoding
of PAL is not MUCH MUCHtrickier than NTSC.
Well, I previously forgot your question... |
One problem is related to the longer phasing cycle and the higher probability
of motion during the 4 frame sequence. The phasing is also more complex,
but solvable. With motion compensation to fix the problem (non
trivial), then the NTSC decoding is made much better yet (because of the
simpler motion issues over the shorter timeframe.) I haven't recently
reviewed the actual math behind doing the PAL decode, and how much work
is needed, AFAIR my evaluation approx 10yrs ago showed that it is much
more complex than for NTSC.
This is NOT directly related to 50Hz vs. 60Hz, because the actual time
difference for decoding based upon the vertical rate, while dealing with
movement is NIL, but it is
the complexity of the signal over a much longer timeframe (dealing with
4 frames instead of 2.) The actual phasing issues for chroma demod are
probably best solved using the BBC approach in their much touted chroma
demod decoder. However, there'll still be mutual interference (between
chroma and luma) on real, moving video without significant motion
savvy processing. A 50Hz NTSC vs. a 60Hz NTSC would be equivalently
decodeable.
In all cases, a near perfect decode isn't a killer when there isn't
movement. Even a less complex full PAL 3D decode is likely useful under
limited circumstances, but it degrades to useless on any moving
video (without motion compensation.)
Perhaps the easiest way to think of it (without lots of math) is that
the nice, neat interleaved (in the frequency domain) chroma and luma
tend to spill/spread if the image isn't stationary. The 3D decoding
techniques of various levels of complexity can be used to mitigate the
effects of alot of the 'spilling.'
For more detailed math, it would take a while to derive!!! 3D combing
itself isn't a panacea (even for NTSC), but the entire 3D decoding
set of algorithms is what makes a good composite video decoder.
USEFUL 3D PAL decoding isn't practical at the consumer level, while
USEFUL 3D NTSC decoding is quite practical. Frankly, the full PAL
solution would likely be a 6 month full time project for me -- but the
real market for such a solution would be too small to justify it now.
Everyone is going to MPEG2/MPEG4 SD/HD.
Further re-iterating: 3D comb decoding is sloppy but understandable
terminology for a composite video decoder that minimizes the chroma
luma interference and also mitigates the detail loss that is so common
with traditional 2D (line by line) comb decoders, and hopefully doesn't
add 3D decoding artifacts like comet-tailing and doesn't create other
kinds of evil artifacts of its own.
John |
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Pete Fraser
Guest
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| Posted:
Sat Oct 30, 2004 3:36 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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"John S. Dyson" <toor@iquest.net> wrote in message
news:clujh4$2hs2$3@news.iquest.net...
| Quote: |
The problem with 3D combing isn't that you cannot do it for PAL, but the
results would be useless without MUCH MUCH more processing.
You keep saying this, but never explain. |
Nor do you answer any of my posts that indicate that 3D decoding
of PAL is not MUCH MUCHtrickier than NTSC. |
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Roderick Stewart
Guest
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| Posted:
Sat Oct 30, 2004 4:01 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <cluj6i$2hs2$1@news.iquest.net>, John S. Dyson wrote:
| Quote: | 2) That there is no longer a tie between display colourimetry and any
Television Standard of the same name
The amazing thing is that NTSC can/does provide the wider gamut (per
my high end video equipment.) Just because a phosphor (mostly legacy)
based display doesn't reach as far into the green color, that doesn't
condemn all phosphor or filter based displays...
|
Yes, it is amazing. Since both systems can manage RGB in to RGB out with
the same voltage levels, the encoding system can make no difference to the
colorimetry of the display. Feed the same RGB values into either system
and you'll get the same RGB values out.
Only the colours of the phosphors in the display can make any difference
to the range of colours that you see, and these are not a function of the
encoding/decoding system.
Rod. |
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John S. Dyson
Guest
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| Posted:
Sat Oct 30, 2004 4:11 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <VA.00000805.01047fce@escapetime.nospam.plus.com>,
Roderick Stewart <rjfs@escapetime.nospam.plus.com> writes:
| Quote: | In article <cluj6i$2hs2$1@news.iquest.net>, John S. Dyson wrote:
2) That there is no longer a tie between display colourimetry and any
Television Standard of the same name
The amazing thing is that NTSC can/does provide the wider gamut (per
my high end video equipment.) Just because a phosphor (mostly legacy)
based display doesn't reach as far into the green color, that doesn't
condemn all phosphor or filter based displays...
Yes, it is amazing. Since both systems can manage RGB in to RGB out with
the same voltage levels, the encoding system can make no difference to the
colorimetry of the display. Feed the same RGB values into either system
and you'll get the same RGB values out.
Actually, if you push the limits you'll NOT get exactly the same values. |
If you stay very safe in the middle, then what you say is more true.
Trying to devolve the argument into 0-255 for each component (or whatever
legal range) ignores the fact that the colors are different, and ignores
the effects of the mapping between RGB <-> YIQ/YUV. The
range of colors that are representable aren't really the entire 0-255
(or 8-248 or whatever) range anyway. This is much more complex than
you imply by using 'RGB' as the colors. I have tried to avoid being
sloppy and over simplifying, avoiding too many details, because as
soon as you shortcut by using the term 'RGB', then the variables
become quite complex. What color
is your Green primary, assuming that you aren't limited to cheap
green phosphors (like many display devices in the US aren't limited.)
What happens when you aren't limited to a reddish orange 'red', and
actually have a better color for your color filter for your display?
| Quote: |
Only the colours of the phosphors in the display can make any difference
to the range of colours that you see, and these are not a function of the
encoding/decoding system.
Please refer to the effects of the matrix, the representable colors and the |
nonlinear effects before making that claim. If you cannot represent
the color, then no matter how hard you try, you won't get the color.
John |
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John S. Dyson
Guest
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| Posted:
Sat Oct 30, 2004 4:27 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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In article <slrnco2tup.c5i.abuse@news.pr.network>,
Paul Ratcliffe <abuse@orac12.clara34.co56.uk78> writes:
| Quote: | On Mon, 18 Oct 2004 12:02:16 +0000 (UTC), John S. Dyson <toor@iquest.net
wrote:
Of course -- you help by agreeing with my point -- the fact is that the PAL
system isn't helping at the point of failure...
Whatever that is. You never actually seem to stick to one point, but go
rambling off. What ARE you talking about?
Hint: the color error in the given example wasn't due to NTSC... More |
often than not, the color errors that I have recently seen (including in the
UK) weren't related to NTSC at all. The most example of improper color
that I had recently seen was a PAL video broadcast. I haven't seen such
ugliness on NTSC in recent years (e.g. actually a green face, while
watching a PAL broadcast, like in the 1960s with NTSC.)
| Quote: |
but that problem is NO LONGER as common as some PAL
advocates might think.
So how is a system that doesn't suffer at all from this phenomenon worse
than one that does?
Remember: the color error example given was on a PAL originated broadcast. |
PAL did an excellent job of reproducing the color errors
as created in the PAL studio. The same problem would happen on NTSC.
It is much more likely to have technical errors in the studio
than for an NTSC signal hue only to be corrupted. It is more
likely that the signal is much more damaged than hue alone, and
in that case the PAL would also be damaged.
So, the old purpose of using PAL (with the complexity and undecodability)
doesn't really manifest very often anymore. It is more likely that
there is a problem with studio equipment than only the hue being
distorted on NTSC. If the HUE is distorted, then there is usually
something else much more wrong with the signal. Even in a PAL
studio, the technicians/engineers have to maintain proper chroma
(camera set-up.)
PALites probably don't realize that we don't tweak and tune our
chroma tint or saturation levels anymore. The electronics are
precise enough, don't drift like in the tube(valve) days, and if
there is a significant tint error, the signal is usually seriously
damaged to the point where the hue isn't important anyway.
Frankly, the last time that I screwed with the chroma on a TV
set, it was on my HDTV to decrease the color saturation.
John |
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John S. Dyson
Guest
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| Posted:
Sat Oct 30, 2004 5:51 am Post subject:
Re: Origins of PAL: 1956 radio engeenering airticle from UK |
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|
In article <21d8eb004d.news@lightfox.plus.com>,
Gareth Rowlands <gareth.see_sig_block@127.0.0.1> writes:
| Quote: | In message <cl0aq3$315b$1@news.iquest.net
John S. Dyson wrote:
However, there is little advantage in using PAL, when it cannot be
decoded fully like NTSC.
(Well, BBC DOES have full decoders, but no-one has them at home.)
That is going to confuse even further some of the willy-wavers from
the rec. groups
"PAL cannot be decoded fully, but there are decoders that can decode
it fully, but don't worry because they do not get used ....."
The purpose for the existant BBC decoders is to convert old material |
from 1", 2" and D2 tape (or composite formats in general.) The difference
between PAL and NTSC is that I can do my own creation of near perfect
archives because I have practically the equivalent of the BBC lab PAL
decoders, except for NTSC. This is especially nice for my archive of LDs that
will likely never be put onto DVD except by me (and other end consumers.)
The DVDs that I have produced from LD look MUCH MUCH better than the
original LD, but that is because the 3D decoders and noise reduction
technology is attainable by the average consumer in NTSC land. Such
near-perfect decoding and creation of very clean (video wise) personal
archives just isn't equivalently attainable in PAL land. It is amazing to be
able to produce a DVD that looks like a DVD, except is admittedly a little
'softer' due to the limited video bandwidth of LDs. The chroma is
amazingly clean, including almost no chroma flashing, no visible crawl
in the luma from the chroma interference, and very stable colors (including
near full field reds being stable, about equivalent to BetaSP, not as
good as DV50 or a signal generator.)
Admittedly, for PAL, the full field chroma will look pretty good like on
NTSC, but the chroma/luma filtering will be missing the 3D processing on
PAL.
| Quote: |
The 'advantage' of having the CPA becomes an albatross, where the
studio user flaws have become more important than the drift in the
electronics nowadays.
As the electrical encoding method has always been capable of carrying
the information from the RGB gamut-space
You aren't really answering the comment about CPA -- do you know what it |
is? Hint: it is essentially the major difference between PAL and NTSC,
and was EXPLICITLY declined by the NTSC team.
John |
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