AVS Forum banner

Status
Not open for further replies.
1 - 10 of 10 Posts

·
AVS Forum Special Member
Joined
·
11,139 Posts
Several nice articles (businessweek.com). Thanks for the post. A little puzzled by this quote, though: "Many broadcasters are angry that cable networks downgrade signal quality to conserve bandwidth." My cable HD signals aren't degraded compared to OTA. Most unneeded error-correction data and station-identification PSIPs are removed, which permits two HD sources per 6-MHz cable slot versus OTA's one. (My brand of cable converter, though, diminishes details slightly with a faint milky haze.) Also the article says HD detail is now 10 times better than standard TV. Hmm. -- John
 

·
Registered
Joined
·
3,220 Posts
Actually HD is 13 times more detail than analog according to my calculations. I don't know where the widely quoted 6 times as much detali came from:

analog: 480x330 =158 K pixles

HD: 1080x1920 = 2.1 M pixles

2.1 M / 158 K = 13


Rick R
 

·
Registered
Joined
·
4,975 Posts
Quote:
Cox's Pickelsimer says the cable company announced in July, 2002, that it would start delivering HDTV service in Las Vegas. The morning after the announcement was made, 11 people were waiting outside Cox offices to subscribe to the new service.
Alright, who's going to fess up and admit they were one of "The Las Vegas Eleven" :D.

Quote:
According to research firm Strategy Analytics, 33 million Americans will have HDTV-capable sets by 2008, about 15% of U.S. homes. But only half of them will want or be able to buy HDTV service.
If I were a betting man I'd place good money against this prediction. Five-six years from now only 15% owning HD capable sets? And only 7% receiving or wanting to get HD signals? Call me an optimist but I think the figures will be much higher than that.


ron
 

·
Registered
Joined
·
107 Posts
Rick, forgive my ignorance, but where do you get 480x330 as the resolution for standard definition? Uncompressed SD is 720x486. That comes to 349,920 pixels, which is just about 1/6th the number of pixels in a 1080i frame. (The ratio is 1:5.926; if you use 720x480 as your SD image size, you get a ratio of exactly 1:6.)


Am I missing something important?
 

·
AVS Forum Special Member
Joined
·
11,139 Posts
Yes, Rick, wondered about the 6X, too. CBS/NBC often brings it up during live HD events. Guess number tweaking can go on endlessly, but IMO it's better to consider measured resolutions rather than scan line numbers and theoretical horizontal HD pixels. Scan lines aren't perceived resolution. Using the measured results in the simplified table here , static B&W 1080i would be 800 X 1638 = 1310400 pixels. But even that's too optimistic, perhaps, as outlined here . So 800 X 1200 = 960,000 may be more like it. For a fair comparison, you'd have to multiply NTSC's 480 active scan lines by ~0.7, too, giving ~330 vertical resolution. And since they aren't broadcasting static B&W test patterns these days, guess you'd have to add in color information comparisons, too. (Note: 330 lines horizontal resolution is per picture height for broadcast NTSC, so 330 X 1.33 is ~440 for 4:3 full width, as 16:9 HDTV is given.) -- John
 

·
Registered
Joined
·
3,733 Posts
so what do you feel the potential ratio is...
 

·
AVS Forum Special Member
Joined
·
11,139 Posts
Sorry, but find the full exercise too tedious here. But the color information for 1638-pixel B&W resolution (static 1080i) is at that simplified-table hyperlink, and you might scale it down for assumed 1200-pixel resolution (or anything in between). Then it's just summing B&W and color, plus looking up broadcast NTSC's color resolution for comparison. Measured NTSC B&W/color would be better. -- John
 
1 - 10 of 10 Posts
Status
Not open for further replies.
Top