Lately I've suffered a lot of big-word
tellytubby talk trying to convince people that video is meaningless. The latest
news is because video decimates Chrominence, this is something dreadful that
makes video unreliable, so you shouldn't believe your eyes but listen to them
instead because they know a lot of big words.
Digital video decimates chrominence
because it is the aspect of analog video that carries hue information. Once
television's signal has travelled thru the Aether and been projected, the job
of chrominence is done. If it hangs around on a digital image, red and blue
chrominence just create noize. There is even a very expensive program to filter
out chrominence for high resolution digital camera images suffering noize problems.
http://www.camerabits.com/QM2.html
The Chrominence of this video is particularly screwed, but this flaw was in the analog video, and perhaps the source itself. Possible reasons will be discussed later, and elsewhere.
http://mbb.harvard.edu/evolution_of_mind_and_brain/chapter_12.pdf
"Three
tiny electron beams (one for each color) sweep across the screen incredibly
fast to activate the pixels. That is, an entire picture is never present at
any instant; rather, a television “image” represents a temporal smearing
of these moving beams. Each beam starts in the upper left corner of the screen
and moves from left to right. Then it jumps back and steps downward a tiny bit
and sweeps from left to right again, and again, until it has swept across all
525 rows of elements that make up the screen-all in one-thirtieth of a second.
It’s sort of like taking a Fourth of July sparkler and moving it incredibly
rapidly back and forth and up and down to get a square image. The three beams
scan simultaneously, illuminating the rows in an alternating regular pattern
called interlacing."
If a television image has been digitized at other than it's native size (the information in an American analog television video digitizes as a 352x240 pixel image) then interlacing becomes a problem. In areas of high movement, the second pass falls behind.
This image shows the effect of interlacing in a rapidly panning scene in a double-sized capture.
Interlace Artifact in Original Source
Chrominence (this page)