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-   -   Blurry HDTV (http://www.avsforum.com/forum/45-local-hdtv-info-reception/50222-blurry-hdtv.html)

Mark II 05-22-2001 10:41 PM

Does anyone notice how blurry a HD picture is when the camera is panning? It is especially noticeable on the football loop from direct TV channel 199. The fixed upon object (player) is great but everything else is blurry when the camera is moving. New to HD people who watch this see it as a big drawback to HDTV.

Any comments?

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Mark II

[This message has been edited by Mark II (edited 05-23-2001).]

[This message has been edited by Mark II (edited 05-23-2001).]

dagman 05-23-2001 01:03 AM

Well . . . It is probably a problem with DTV in general, not just HDTV. I'd say it is an MPEG2 compression artifact. Perhaps it can be reduced by better encoders. But since the compression scheme works by taking advantage of redundancies in adjacent frames/fields, a fast pan eliminates such redundancies so it doesn't work so well for fast pans.

But yeah, I noted the blurryness when watching the NCAA final.

Don Landis 05-23-2001 03:09 AM

You are partially correct. Motion artifacts will cause this but also there are some problems with CCD chip sets in digital cameras that product this artifact in horizontal pans. This is visible in some cameras more than others. I've seen it real bad on Panasonic cameras, some Hitachi, almost non-existent on Sony and Ikegami. Another source of horizontal bluriness in video is a result of editor error in edited video that is rendered for output. When the edges seem to come apart it is that the fields are separating during the horizontal motion. This is caused by the editor rendering his video with the wrong field order. This is pretty common error. I have seen several commercials produced by top production houses that have this problem. It is easily fixed in most editors.

Most of the time low resolution TV these problems have been masked by the low res but with HDTV the end viewer is beginning to notice these problems.

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Don Landis
Home Theater Pics at: www.scubatech.com Last updated 3/25/01

Frank 05-23-2001 05:49 AM

I have only noticed this once and that was during the NBA game on NBC. It was very obvious. I e-mailed the station engineer about it and he said they were using only 13 megabits per second insteaed of the full 19.2. I think that was the source of that problem.
I am wondering if in your case, it has something to do with phosphor persistence of a CRT display device.

Frank

Kipp Jones 05-23-2001 07:26 AM

This problem seems to vary from station to station and program to program. Has anyone noticed any patterns?

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Kipp

Sarahlea 05-23-2001 10:06 PM

In a PBS demo showing protions of an Alabama football game, the crowd as well as the foreground were simply supurb. I was blown away.

Bill 05-24-2001 12:29 AM

I'm with you Frank. Not using the full bandwith is the problem. I never see this problem on HD-HBO. Some have knocked HD-HBO but I think their HD is excelent.



[This message has been edited by Bill (edited 05-24-2001).]

Man E 05-24-2001 06:14 AM

This is an observation, not a complaint:

I have noticed motion artifacts having to do with the color red (which, IIRC, is a major victim in MPEG compression). It was particularly evident on the opening sequence of Leno last year. As the camera would fast pan the (darkened) crowd, the bright red studio lights on the back wall would macro-block and pixilate. The pixilation would also happen to the band and other detailed objects if the panning was very fast (which it was frequently).

My NBC affiliate (WDIV/Detroit) dropped one of its digital channels soon after I mentioned this (not that it was my doing, but sorry guys, I liked WindsorCam too!), but the problem persisted with just a weather radar scan channel active. That is, until NBC apparently fixed it by not doing those pans anymore! I'm serious. The entrance camera work was significantly tamed in the past year. Every once in a while they'll do a slower version of the problematic ones, but the panning (all panning I think) has been slowed way down.

It seems like fast panning will eventually just fill the pipe (even the full 19+Msps pipe). Especially when the panning involves complex content like a crowd. The faster it goes, the more data changes each frame, and the closer to the limit the transmission gets.

2c


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JMartinko 05-24-2001 02:40 PM

Man E
For what it is worth, on last nights show they did the old fast scan during the intro, and I saw a lot of artifacts again while they were moving the camera. They are much better, but every so often the camera men still get carried away.

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jm in Boulder

Mark II 05-24-2001 11:35 PM

Great info, however, in my case I only notice a blurred or out of focus background. I do not notice any artifacts or variance in image quality. Actually it is so clear that you can't help but notice the blurry background when panning the camera.

I have not seen it when playing DVD's so I guess it is just a compression problem during the transmission. I'm sure as HD progresses this too will be eliminated. Still, HD is just totally mesmerizing! Just hope the equipment we now use will still work.

I'm using a RCA DTC-100 Sony VW10HT Sony ES9000DVD


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Mark II


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