JVC Professional APRIL 2007 NAB-2007 The ProHD Report
Copyright 2007 JVC Professional Products Company All rights reserved Page 13 of 43
In 2004, EBU recommended the use of progressive scanning throughout the
acquisition and delivery chain. There was one overriding logical fact driving this
decision: CCD and CMOS imagers are progressive devices (although we can
electrically operate them in interlaced mode) and all future consumer displays will
be of native progressive design (rear projection, front projection, plasma, flat LCD
etc.) Why throw away temporal resolution and compression efficiency by making the
digital intermediate processes and distribution in an interlaced format.
The European desire: Let’s be progressive from glass to glass.
BBC tests concluded that the average home viewing distance in the typical UK home
is also about 9 feet. At that viewing distance, with a 50” HD monitor, it was clear in
these BBC tests that a 1280x720 image would saturate the human eye with details,
thus to increase the acquisition, the delivery resolution and the monitor resolution to
1920x1080 would not increase the perceived resolution by the human eye.
It was noted that if the monitor was significantly larger than 50” at the same viewing
distance, or the same 50” monitor at a significantly lesser viewing distance, an entire
acquisition delivery chain of 1920x1080p50 would indeed improve the perceived
resolution by the human eye, or, to say it differently, prevent the viewer from seeing
“lines or pixels” in a 720p chain. Although the European decision is progressive,
there are now planned several 1080i services, including BBC. But in the question
between 1080p or 720p, the added costs in all areas of acquisition, processing,
delivery and display in 1080p are NOT justified at this time, the Europeans conclude.
It is clear: About 75% of the US HDTV audience will be watching on 50” displays
or smaller, and with a native resolution of 1280x720 (or the related 1366x768), and
be 9 feet from the screen as an average, from now through 2010. The long term cost
effective HD format choice for HD ENG & news for a TV station is 1280x720p60,
even if you are a “1080i TV station”. 720p converts beautifully to 1080i going into
master control. The ProHD format is very well suited for great looking, economical
HD news from the field.
The shortest path between two points is a straight line! That says it all. The ATSC
delivery over the air directly to the home ATSC receiver (whether STB or built-in) is
the highest quality consumer level HD delivery available, bar none.
Not even the emerging HD-DVD and Blue-ray may be as good, with all its multi-
generational processing, when compared with a TV stations live HD studio camera
shots sent over the air directly to the home viewer’s ATSC HD set.