Doubling Your TV Pleasure
Eliminating TV Scan Lines
by Jim Bray
Note: TechnoFILE's test unit was supplied by K&W
Planned obsolescence could be hitting the DVD player market already -
but there may be something you can do about it.
An increasing number of DVD players on the market offer a feature called
"progressive scan," and it's a nice upgrade compared with today's "run
of the mill" DVD players. But what if you've already bought a DVD player?
Is it now time to chuck it into a land fill?
Heaven's no! While progressive scan is wonderful, it isn't the be-all
and end-all. Besides, if you have a TV with component video inputs, you
can upgrade your DVD player - and your TV reception - in one swell foop.
You do this by adding a progressive scan display interface, a little
box that connects between your TV and your DVD player, VCR, A/V receiver,
or satellite tuner. It's neat, too.
My first experience with progressive scan came courtesy of Sony's $1500
high end DVPS9000ES DVD player and, though it didn't benefit every DVD
I played, it improved enough of them to convince me of progressive scan's
value. The resolution was actually a little lower than I get from my already-line-doubled
TV, but the colors! Wow!
So it didn't take a lot of convincing to get me playing with Silicon
Image's iScan Pro, a $900 add-on box that does everything mentioned
above, and more.
The tiny iScan Pro is only about the size of two DVD cases stacked together,
yet it yields pretty big results on your TV screen.
Why? Well, in a nutshell, today's TV tubes use a scanning system in which
each frame of the picture is broken up into two separate fields, each
of which his displayed 30 times each second. The first field, consisting
of some 240 "odd numbered" scan lines, is followed by the second field
of even-numbered lines. This is called "interlacing" and, while it worked
fine in the old days when resolution was low and TV's were small, it's
a pain in the eye on today's big, high resolution televisions.
If you've ever looked at a big screen TV and noticed what appear to be
black lines running horizontally across the picture, you'll know what
Progressive scan, on the other hand, is how today's computer monitors
work. They display the entire 480i picture (480 scan lines, interlaced)
at once. The result is called 480p (progressive). The process is also
called line doubling and, while this isn't completely accurate (and there's
a lot more to it), it basically takes the output signal from your TV,
VCR, or DVD/Laserdisc player and converts it to almost high definition
The iScan Pro will take composite, S-Video, and Component video input,
work its digital magic on it, and output it via VGA connection, which
means it'll display on your computer monitor or, with an adapter, a TV
equipped with component or "BNC" video inputs.
I used it on my TV's 480p component input and it looked terrific.
The unit comes with a set of picture controls on its tiny front panel,
including brightness, contrast, saturation, hue and sharpness, though
I found no need to adjust any of them from their default positions. There's
also a three position switch that tells the iScan Pro which signals to
prioritize, so that (for example) if you turn on your DVD player it automatically
switches to that input from whatever it's currently displaying.
An aspect ratio control lets you adapt the product to wide or standard
screen TV's. I set it to "normal" mode for my widescreen TV and never
had to touch it again.
The progressive output from my non-progressive DVD player looked outstanding,
but what I was particularly interested in seeing the iScan Pro do was
upconvert my digital satellite TV receiver. That's because my TV automatically
line doubles these signals, but I've never been happy with the resulting
softness of the picture. The iScan Pro didn't help many channels' signals,
but it did a very good job on channels that were better than average to
begin with, which was worth the price of admission.
Couple to that its terrific performance with DVD's and you have an affordable
way of upgrading your video components.
Considering its price and the fact it upconverts multiple signals, the
iScan Pro is a pretty nifty unit that offers more value than a standalone
progressive scan DVD player.
Jim Bray's technology columns are distributed by the TechnoFILE and Mochila Syndicates. Copyright Jim Bray.
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