Transparency (data compression): Difference between revisions

Revision as of 21:50, 2 July 2017

Revision as of 03:24, 13 October 2017

Line 8:

Transparency, like sound or video quality, is subjective. It depends most on the listener's familiarity with digital artifacts, their awareness that artifacts may in fact be present, and to a lesser extent, the compression method, [[bit-rate]] used, input characteristics, and the listening/viewing conditions and equipment. Despite this, sometimes general consensus is formed for what compression options "should" provide transparent results for most people on most equipment. Due to the subjectivity and the changing nature of compression, recording, and playback technology, such opinions should be considered only as rough estimates rather than established fact.

Judging transparency can be difficult, due to [[Observer-expectancy effect|observer bias]], in which subjective like/dislike of a certain compression methodology emotionally influences his or hertheir judgment. This bias is commonly referred to as ''[[placebo]]'', although this use is slightly different from the medical use of the term.

To scientifically prove that a compression method is ''not'' transparent, [[double-blind]] tests may be useful. The [[ABX test|ABX method]] is normally used, with a [[null hypothesis]] that the samples tested are the same and with an [[alternative hypothesis]] that the samples are in fact different.