Picture artifacts on DVDs (1 Viewer)

[Jakob_S]

When I see movies on DVD I notice a lot of irretating artifacts, but I don't know them by name.

Can anyone explain and maybe give some examples with screen shots of the following artifacts?

- shimmer

- pixelization

- aliasing

I might have some other "artifacts words" too that I don't know the meaning of, but I can't remember them right now, so I'll have to get back on that later...

I Hope you guyz can help me. Thanx.

 

[Gareth Flynn]

There's some nice explanations and illustrations of artifacts at:
http://www.michaeldvd.com.au/Article...Artefacts.html

 

[Jakob_S]

Thanx, but I already know that place though. But hey, I just spotted that they have an explanation of "aliasing".

I'm still searching for explanations of the following, though:

- shimmer

- pixelization

And I've found some more expressions, that I don't know the exact meaning of:

- Block Noise

- Mosquito Noise

An artifact I'm really annoyed of, is when some things in the background have "moving/unstable colurs" or "running stribes". What is this artifact called? Usually I spot it around small sharp edges and try to ignore the "phenomenon". But sometimes it's pretty large, forexample on a roof in the background or on a man's tie. On some interactive DVD menus around the 'text options' I see this artifact too.

 

[Inspector Hammer!]

Jakob, how do you have your dvd player connected to your monitor? If you have it conneted via composite, or RCA cables, it will produce the color noise your describing, depending on the quality of your t.v.'s comb filter. If you have it connected via s-video, this shouldn't be a problem, s-video eliminates any color noise from the image because it completly bypasses your t.v.'s comb filter and goes straight to your t.v.'s color decoder.
And shimmer can be caused by either a bad dvd transfer, or bad 4x3 downconverison by your dvd player. It shows itself with all of the horizontal edges in the film seeming to "shimmer" or fluctuate, particularly when the camera moves slowly up and down.
Pixelation appears as colorful blocks that randomly pop up all over the picture causing drop outs in both the picture and sound, and on occasion can cause your player to freeze up.

 

[Jakob_S]

Thanx for the explanations
I haven't connected my DVDplayer via s-video, so that might be the problem. But why do I see the same kind of artifacts when I play DVDs via DVD-ROM and use the PC monitor then?
I fully understand the word "pixelization" now I think. I also understand your explanation of "shimmer", but I guess I have to see this artifact next to the explanation to fully understand the meaning of it.
And I' still looking for explanations of:
- Block Noise
- Mosquito Noise