| Subjective Video Quality |
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Information AboutSubjective Video Quality |
| CATEGORIES ABOUT SUBJECTIVE VIDEO QUALITY | |
| film and video technology | |
| digital television | |
| video codecs | |
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HOW IT CAN BE MEASURED Main idea of measuring subjective video quality is the same as in Mean Opinion Score for audio. Assume that you want to evaluate subjective video quality of a video processing system. To do this you should go through following steps:
Of course, to make professional comparison you should take into account lots of parameters of viewing conditions: room illumination, display type, brightness, contrast, resolution, viewing distance, age and education level of experts - all this can influence the results. TESTING METHODS There is enormous amount of ways how you can show video sequences to expert and to record his or her opinion, and a few of them have been standardized. They are thoroughly described in ITU-T recommendation BT.500. One of standardized methods is DSIS - Double Stimulus Impairment Scale: expert is presented with unimpaired reference video, than with the same video impaired, and after that he is asked to vote on the second video using impairment scale (scale from "impairments are imperceptible" to "impairments are very annoying"). ANALYSIS OF RESULTS Opinions of experts can be averaged; average mark is usually given with Confidence Interval . Additional procedures can be used for averaging, for example experts who give unstable results can be rejected (for instance, if their correlation with average opinion is small). SEE ALSO EXTERNAL LINKS
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