Digital encoding errors

[UniSol GR77]

Someone mentioned this in a review. What does it mean?

[UniSol GR77]

Hey? Need help on this.

[CasualKiller]

1) a review of what?

2) a link to the review

There's no way we can figure out what you are talking about with such a vague statement.

[UniSol GR77]

Originally Posted by CasualKiller

1) a review of what?

2) a link to the review

There's no way we can figure out what you are talking about with such a vague statement.

For example, Star Trek Season One at HighDef.

http://bluray.highdefdigest.com/675/startrektos_s1.html

[4K2K]

Originally Posted by UniSol GR77

For example, Star Trek Season One at HighDef.

http://bluray.highdefdigest.com/675/startrektos_s1.html

I can't see where that link says "digital encoding errors", but it does have this paragraph:

On the downside, the show's photography is frequently grainy, sometimes quite a bit so, and the grain is not always adequately digitized. It appears that noise reduction has also been employed to tame the worst of it, a process that softens detail at times and can cause its own artifacts. Viewers with keen eyes will notice posterization and pixelation problems in a number of episodes, notably on the wall behind Kirk at time code 28:30 in 'Charlie X'. A first instinct may be to blame the VC-1 compression, however the same artifact is present at the same spot on both the DVD and HD DVD editions of these Remastered episodes. Whatever the cause of this problem (likely aggressive noise reduction or digital recoloring), is part of the master, not something specific to the Blu-ray encoding. For what it's worth, the same scene in the pre-Remastered 2004 DVD set does not show any pixelation.

I haven't seen this title so I'm just guessing based on the review:

When it says things like "the grain is not always adequately digitized" it might be meaning they didn't encode it with a high enough bitrate to be able to properly encode the film grain, and they also used noise reduction (DNR) to get rid of some of it. I think Posterization can also occur when video isn't encoded with a high enough bitrate - or if they convert something from a high number of colours like 12 bit to 8 bit and don't do it the best way. It might also occur, like the reviewer says with too much alteration in the remastering stage, especially if they were working at a lower colour depth.

Posterization according to wikipedia:

Posterization of an image occurs when a region of an image with a continuous gradation of tone is replaced with several regions of fewer tones, resulting in an abrupt change from one tone to another. This creates an effect somewhat similar to that of a simple graphic poster.
http://en.wikipedia.org/wiki/Posterization

Pixellation according to Wikipedia:

In computer graphics, pixellation (or pixelation in American English) is an effect caused by displaying a bitmap or a section of a bitmap at such a large size that individual pixels, small single-colored square display elements that comprise the bitmap, are visible to the eye.

Noise reduction (eg. DNR) is where they basically soften/blur the picture a bit. It makes it easier to encode but obviously makes it more blurry/soft. It reduces the grain and the detail and if done badly/too much can make people look like cartoons.