SIGHT & SOUND
Sponsored by WireLogic
HDTV
demystified
HIGH-DEFINITION TELEVISION (HDTV) is the hottest item in consumer
electronics today, and, with an estimated 88 million sets expected to be sold
over the next three years, there is no sign of slowing. Thanks to the picture
quality and sleek look (especially flat-panel models), it is no surprise. Yet,
despite HDTV’s popularity, much of the terminology and technology behind
that beautiful picture and amazing sound can still be confusing.
What do all those numbers (and acronyms) mean?
Digital television (DTV) broadcasting is the new standard for delivering
spectacular picture and sound. In 2009 it will completely replace television
broadcasting as we know it. Most televisions capable of showing digital broadcasts offer high definition, while some offer a lower-resolution picture and are
known as enhanced definition (EDTV). The displays are labeled based on
their capability to show lines of resolution, such as 480i, 480p, 720p, 1080i
and 1080p.
The number identifies how many lines run horizontally across the screen
in order to make one complete picture; the higher the number, the more detail
you will see. The “i” stands for interlaced, meaning the lines of resolution are
drawn odd first (lines 1, 3, 5, 7, etc.), then even (lines 2, 4, 6, 8, etc.). The
“p” stands for progressive, meaning the lines are drawn in order, yielding a
smoother, more detailed picture compared to an interlaced version with the
same number of lines. So, a set that’s labeled 1080p can show up to 1080 lines
horizontally across the screen, drawn progressively in numerical order from
top to bottom, thus yielding a better picture than a set labeled 1080i, with
interlaced lines.
HDTV starts at 720p, while EDTV sets usually display no greater than 480p
resolution. Anything broadcast to EDTV sets at a higher level is down-convert-ed (digitally downgraded) to 480p.
