Noise around the lettering?
 

I have noticed that around some lettering on flat screen DTV sets there is what I will call video noise around the letters in a square area. Also in some dark areas the is this same effect. Cant capture it with a camera or I'd post a pix. Is it being broadcast that way. Is it the receiver RF or the way its decoded?
At times there seems to be a ghost around such lettering or logo some of the time, all the way around. I was thinking it might be the way the TV software dithers the pixels to make a picture but the effect is a bit too extreem to me.
Any body know.

Hi-

If you are referring to what I could call a "wrinkled" look in the area closely surrounding text or other sharp, higher-contrast details on digital TV broadcasts (and much worse if it is from satellite or cable), that is a side effect of the limits on digital date rates in the TV signals.

Read about "Gibbs Effect" (mosquito noise) here:
http://www.embedded.com/design/real-...oise-reduction
jr

This must appear mostly in flat HD tvs. My Fatherinlaw's house (boy spellcheck put a red line under that new word) they replaced their analog 21" tv with a 30" flatter and the picture and color look so bad I don't even want to turn it on.... They have cable, same controller on both sets.... But the old tv, before it died, looked really good....

Start your "investigation" by watching network programming via an antenna -- not by cable or satellite. Re-broadcasters will cough up only enough bandwidth as is necessary to minimize complaints. And non-network programming could have non-HD beginnings. (I suppose local live news would be OK.) Then you can see if it's the content or the display.

(This would be on the primary HD channel, not a sub-channel.)

Chip