观看喜欢的视频时 画面质量往往会被忽视

Research from Rice University's Department of Psychology¹ finds that if you like what you're watching, you're less likely to notice the difference in video quality of the TV show, Internet video or mobile movie clip（电影片段） . The findings come from the recently released study "The Effect of Content Desirability（愿望，有利条件） on Subjective² Video Quality Ratings" authored by Philip Kortum, Rice professor-in-the-practice and faculty³ fellow. The study appears in the journal Human Factors.

"Research has been done asking if people can detect video quality differences," Kortum said. "What we were looking at was how video quality affects viewers in a real way."

Using four studies, Kortum, along with co-author Marc Sullivan of AT&T Labs, showed 100 study participants 180 movie clips encoded at nine different levels, from 550 kilobits（千比特） per second up to DVD quality. Participants viewed the two-minute clips and then were asked about the video quality of the clips and desirability of the movie content.

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Kortum found a strong correlation⁴（相关，关联） between the desirability of movie content and subjective ratings of video quality. #

"At first we were really surprised by the data," Kortum said. "We were seeing that low- quality movies were being rated higher in quality than some of the high-quality videos. But after we started analyzing⁵ the data, we determined⁶ what was driving this was the actual desirability of the content.

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"If you're at home watching and enjoying a movie, we found that you're probably not going to notice or even concern yourself with how many pixels the video is or if the data is being compressed," Kortum said. "This strong relationship holds across a wide range of encoding levels and movie content when that content is viewed under longer and more naturalistic viewing conditions." #

The findings run counter to the popular belief that Americans are striving for（争取，奋斗） and must have the best video quality at their fingertips all the time. #

The importance of the research could be far-reaching in the way cable companies, online video and news providers shave megabits of compression to save on the ever-growing need for bandwidth.

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"With these new delivery platforms comes the concern about how to adequately address the trade-off between the bandwidth of the delivery channel and the resulting video quality," Kortum said. "This trade-off is a concern not only for PCs and mobile devices but for mainstream⁷ content providers in the television arena（舞台，竞技场） as they move to deliver high-quality content over limited broadband delivery channels."#p#分页标题#e# #