Noise... better description?

[Duminas]

What truly IS Noise? I've gone through the glossary here, but the description that's provided is too confusing (for me, at least)...

Is it in the audio stream or video...?

Thanks for any help! Sorry if this is really stupid, but none of the descriptions I find are simple enough for me to understand.

[BJ_M]

noise (as in video noise) is something that should not be on your video -- ussually ..


sometimes i ADD noise to a video on one or more color channels (known as dithering) for various reasons -- ussually when a signal is color compressed or reduced in size - adding small amounts of noise is typical ..

[SaSi]

The proper definition of noise in a signal is the existense of an additional signal whose value as a function of time is random. Being random it is very difficult to remove.

The most common example of noise in an audio signal is the tape hiss.

A common noise example in video signals is the well-known TV snow. (Actually the TV snow is not the noise itself but the result of noise - or low signal to noise ratio).

Noise has a very broad scope of use. Imagine, for example, a thread in dvdrhelp where someone asks users their opinion on a Pioneer DVDR A05. If I answer telling I am unhappy with it (I don't own one), I am adding noise to the poll. My response is measurable and visible to the thread, however my feedback is random or biased, and irrelevant to the question. This is a different kind of noise, of course. (Perhaps my whole response here is just noise )