Visual "clipping"?

Hi:

Clipping in an audio signal results when an audio device receives a
signal that is too loud. The audio signal distorts into square-waves
because the "tops" of the signal are flattened. The device cannot
handle power levels over a certain level. When this level is exceeded,
clipping occurs. Clipping is usually harsher in digital devices than
in analog devices. Analog clipping tends to be fuzzy and soft compared
to digital clipping.

What is the visual-equivalent of "clipping"? Is there a difference
between analog and digital in terms of visual-clipping? If so, what is
the difference?

Auditory-clipping can damage speakers. Can visual-"clipping" damage
monitors?


Thanks,

Radium

In article <1188874984.222039.197660@y42g2000hsy.googlegroups .com>,
Radium <glucegen1@gmail.com> wrote:

> Hi:
>
> Clipping in an audio signal results when an audio device receives a
> signal that is too loud. The audio signal distorts into square-waves
> because the "tops" of the signal are flattened. The device cannot
> handle power levels over a certain level. When this level is exceeded,
> clipping occurs. Clipping is usually harsher in digital devices than
> in analog devices. Analog clipping tends to be fuzzy and soft compared
> to digital clipping.
>
> What is the visual-equivalent of "clipping"? Is there a difference
> between analog and digital in terms of visual-clipping? If so, what is
> the difference?

Clipping causes whites lose all texture -- very similar to overexposed
film.

> Auditory-clipping can damage speakers. Can visual-"clipping" damage
> monitors?

No. Prolonged blacks can damage television transmitters, however (video
is inverted for transmission, so black requires full power from the
transmitter).

Isaac

On Sep 3, 8:27 pm, isw <i...@witzend.com> wrote:

> In article <1188874984.222039.197...@y42g2000hsy.googlegroups .com>,

> Radium <gluceg...@gmail.com> wrote:

> > Hi:

> > Clipping in an audio signal results when an audio device receives a
> > signal that is too loud. The audio signal distorts into square-waves
> > because the "tops" of the signal are flattened. The device cannot
> > handle power levels over a certain level. When this level is exceeded,
> > clipping occurs. Clipping is usually harsher in digital devices than
> > in analog devices. Analog clipping tends to be fuzzy and soft compared
> > to digital clipping.

> > What is the visual-equivalent of "clipping"? Is there a difference
> > between analog and digital in terms of visual-clipping? If so, what is
> > the difference?

> Clipping causes whites lose all texture -- very similar to overexposed
> film.

What does this look like on a screen?

> > Auditory-clipping can damage speakers. Can visual-"clipping" damage
> > monitors?

> No. Prolonged blacks can damage television transmitters, however (video
> is inverted for transmission, so black requires full power from the
> transmitter).

Prolonged black can damage a monitor/screen? That's weird. White is
analogous to the loudest sound a loudspeaker can playback. Black is
analogous to a loudspeaker not being feed any signal.

When the power-supply of the monitor/screen is turned off, the monitor/
screen is black because it not receiving any voltage.

I would think that extremely-bright white would damage the screen
because the brightest white results from the highest voltage applied
to the Reds, Greens, and Blues [equal intensities of R, G, & B -- if
combined -- appear white to our eyes when emitted by an electronic
monitor] in a particular area of the monitor/screen. If the voltage
exceeds this for prolonged periods of time, that region of the screen
will burn out, much like forcing an extremely-high voltage audio
signal into a speaker will cause the speaker to short-circuit and the
diaphragm to pop and/or melt. Many instructions manual for speakers
give direction not to reach or go above the clipping point and
clipping damages the speakers. Wouldn't something similar happen to a
monitor/screen [whether it's a CRT, plasma, or LCD] if it was forced
to display light-intensities beyond its limits?

"isw" wrote ...
> Radium wrote:
>> Auditory-clipping can damage speakers. Can visual-"clipping" damage
>> monitors?
>
> No. Prolonged blacks can damage television transmitters, however (video
> is inverted for transmission, so black requires full power from the
> transmitter).

Prolonged bright areas (whether clipped or not) will damage CRT
monitors. I have two on the bench right now to have their CRTs
replaced because the image is burned-in. They came from a
security/survelience application and you can somewhat see the
hallway and the doors they were monitoring.

Radium wrote:
> On Sep 3, 8:27 pm, isw <i...@witzend.com> wrote:
>
>> In article <1188874984.222039.197...@y42g2000hsy.googlegroups .com>,
>
>> Radium <gluceg...@gmail.com> wrote:
>
>>> Hi:
>
>>> Clipping in an audio signal results when an audio device receives a
>>> signal that is too loud. The audio signal distorts into square-waves
>>> because the "tops" of the signal are flattened. The device cannot
>>> handle power levels over a certain level. When this level is exceeded,
>>> clipping occurs. Clipping is usually harsher in digital devices than
>>> in analog devices. Analog clipping tends to be fuzzy and soft compared
>>> to digital clipping.
>
>>> What is the visual-equivalent of "clipping"? Is there a difference
>>> between analog and digital in terms of visual-clipping? If so, what is
>>> the difference?
>
>> Clipping causes whites lose all texture -- very similar to overexposed
>> film.
>
> What does this look like on a screen?

An area of just plain white.

>>> Auditory-clipping can damage speakers. Can visual-"clipping" damage
>>> monitors?
>
>> No. Prolonged blacks can damage television transmitters, however (video
>> is inverted for transmission, so black requires full power from the
>> transmitter).
>
> Prolonged black can damage a monitor/screen? That's weird.

TRANSMITTERS. HE SAID TRANSMITTERS.

> White is
> analogous to the loudest sound a loudspeaker can playback. Black is
> analogous to a loudspeaker not being feed any signal.

NOT ON A TRANSMITTER. Yeesh. Did you actually read that paragraph AT
ALL???

Richard Crowley wrote:
> "isw" wrote ...
>> Radium wrote:
>>> Auditory-clipping can damage speakers. Can visual-"clipping" damage
>>> monitors?
>> No. Prolonged blacks can damage television transmitters, however (video
>> is inverted for transmission, so black requires full power from the
>> transmitter).
>
> Prolonged bright areas (whether clipped or not) will damage CRT
> monitors. I have two on the bench right now to have their CRTs
> replaced because the image is burned-in. They came from a
> security/survelience application and you can somewhat see the
> hallway and the doors they were monitoring.

ANY static image for a prolonged time will cause burn-in on a CRT or
plasma display. The brighter it is, the less time it takes, but it
doesn't have to be pure white for burn to occur. Simply displaying 100%
white won't cause instant death of a monitor, however, the way a clipped
signal can damage a speaker.

On Sep 3, 9:25 pm, "Richard Crowley" <rcrow...@xp7rt.net> wrote:

> Prolonged bright areas (whether clipped or not) will damage CRT
> monitors.

Can damage occur to a CRT/Plasma/LCD monitor from an area that is
extremely-bright for an extremely short time? Let's say one attempts
to force 2400 lumens of light-intensity out of an area of the monitor
for around 5 seconds. What damage would affect that region of the
screen?

Warning! Crazy scenarios are presented below. None-the-less I still
find them interesting:

Try to force 100,000,000 lumens out of a square-shaped, pinky-finger-
sized area of an LCD monitor. Now what would happen? Would the organic
material present in that area catch fire?

For an acoustic-analogy, let's say one tries to force a 400,000 Hz,
144 dB sine-wave tone out of a Bose loudspeaker. The result: a very
expensive fire. The plastics/paper in the speaker would likely ignite.

Radium wrote:
> On Sep 3, 9:25 pm, "Richard Crowley" <rcrow...@xp7rt.net> wrote:
>
>> Prolonged bright areas (whether clipped or not) will damage CRT
>> monitors.
>
> Can damage occur to a CRT/Plasma/LCD monitor from an area that is
> extremely-bright for an extremely short time? Let's say one attempts
> to force 2400 lumens of light-intensity out of an area of the monitor
> for around 5 seconds. What damage would affect that region of the
> screen?

Ummm, probably none, as the output would be limited by the drive systems
of the display. The only thing you could "force" into it would be a
high-voltage video signal, which would fry the input circuitry, but
probably not a lot else.

To extend the analogy to audio, your speaker would have its own built-in
amp with limited output power; you can't "force" it to output more power
into the speaker.

> Warning! Crazy scenarios are presented below. None-the-less I still
> find them interesting:
>
> Try to force 100,000,000 lumens out of a square-shaped, pinky-finger-
> sized area of an LCD monitor. Now what would happen? Would the organic
> material present in that area catch fire?

And how exactly would one do that, since LCDs don't actually produce
light on their own?

On Sep 3, 9:07 pm, Radium <gluceg...@gmail.com> wrote:
> On Sep 3, 8:27 pm, isw <i...@witzend.com> wrote:
> > > What is the visual-equivalent of "clipping"? Is there a difference
> > > between analog and digital in terms of visual-clipping? If so, what is
> > > the difference?
> > Clipping causes whites lose all texture -- very similar to overexposed
> > film.
>
> What does this look like on a screen?

If you can find an old analog TV or monitor, just turn up the contrast
control way too high. All the greys darker than a certain level
become black, all the greys lighter than a certain level become
white. Information is lost.

On Tue, 04 Sep 2007 04:31:27 GMT, Matt Ion <soundy106@gmail.com> wrote:

>NOT ON A TRANSMITTER. Yeesh. Did you actually read that paragraph AT
>ALL???

Usually he only reads half. Get used to the phenomenon "Radium".

-m-
--
Official website "Jonah's Quid" http://www.jonahsquids.co.uk