Video Quality Technical Term Glossary

[Spitfrnd]

I posted this question in the blu-ray movie forum and it was moved to displays. Frankly I think it has more to do with movies but it may be better off here. In any event, I have noticed that a number of the video quality reviews contain terms that I have not been able to find defined. Some examples include crush, aliasing, artifacting, ringing and banding. I have looked at the glossaries here
Glossary of Audio Terms but do not find these, among some others. Is there a definitive glossary for the the technical terms used in Blu video quality reviews? If not, maybe someone could tell me what those above terms mean? Thanks much.

[kpkelley]

This thread may help....Link.

[Clark Kent]

Try the first post in this thread for a glossary of terms:

http://www.avsforum.com/avs-vb/showthread.php?t=1168342

[Anthony P]

I don't read reviews, but I will go with some definitions.
artifacting: generic term that basically means there is something artificially wrong but not what is wrong (unless qualified)

crush: usually seen as "crushed blacks", basically what you need to realize is that digital video each colour has a numerical value, what happens is that sometimes things are pushed to such a limit (i.e. for crushed blacks too dark) so that detail is lost because there is not difference to differentiate between the values. For example, let's say there is something in the shadows, and you could barely see it, now let's say the scene is darkened and now you can't see it in the shadow any more, so that info got "crushed", squeezed to just black

banding: as the name points out it has something to do with creating bands. it could be related to crushing but not because of darkness and it is in horizontal (don't remember seeing vertical ones) stripes (bands). Basically what happens is that in a scene (like a sunrise) where you should have a smooth gradient (for example from bright orange on the horizon to dark blue at the top) what happens is that it does not look that smooth and it looks as if the colours remain the same for a bit and then change a lot. Almost as if someone used different paints (i.e. bright orange, darker orange, orange-blue, orange-dark blue, dark blue.


ringing: is an artefact where you get some kind of ghosting. Like a ring of a bell where, the first hit is loud and then it is followed by less and less loud rings. Ringing can happen on a sharp edge (i.e. a black area going to a white one) where it looks as there is some influence (i.e. after the black there seems to be some light grey mixed with the white)