Motion interpolation: Difference between revisions

[[File:Interframe motion interpolation.webm|thumb|right|Comparison of a slow down video without interframe interpolation (left) and with motion interpolation (right).]]

'''Motion interpolation''' or '''motion-compensated frame interpolation''' ('''MCFI''') is a form of [[video processing]] in which intermediate film, video or animation frames are generated between existing ones by means of [[interpolation]], in an attempt to make animation more fluid, to compensate for [[display motion blur]], and for fake [[slow motion]] effects.

Some [[video editing software]] and [[plug-in (computing)|plugins]] offer motion interpolation effects to enhance [[slow motion|digitally-slowed video]]. [[FFmpeg]] is a [[free software]] non-interactive tool with such functionality. [[Adobe After Effects]] has this in a feature called "Pixel Motion". AI software company Topaz Labs produces Video AI, a video upscaling application with motion interpolation. The effects plugin "Twixtor" is available for most major video editing suites, and offers similar functionality.

Motion interpolation on certain brands of TVs is sometimes accompanied by visual anomalies in the picture, described by CNET's David Carnoy as a "little tear or glitch" in the picture, appearing for a fraction of a second. He adds that the effect is most noticeable when the technology suddenly kicks in during a fast camera pan.<ref name="Six things"/> Television and display manufacturers refer to this phenomenon as a type of [[digital artifact]]. Due to the improvement of associated technology over time, such artifacts appear less frequently with modern consumer TVs, though they have yet to be eliminated entirely "the artifacts happens more often when the gap between frames are bigger".{{citation needed|date=June 2024}}

As a byproduct of the perceived increase in frame rate, motion interpolation may introduce a "video" (versus "film") look. This look is commonly referred to as the "'''soap opera effect'''" ('''SOE''')<!--The bold is because this phrase redirects here-->, in reference to the distinctive appearance of most [[television network#United States|broadcast television]] [[soap opera]]s or pre -2000s [[Multiple-camera setup|multicam]] [[sitcom]]s, which were typically shot using less expensive [[List of broadcast video formats|60i]] video rather than film.<ref name="Weird Effects">{{cite web |url=http://www.crunchgear.com/2009/08/12/help-key-why-hd-video-looks-weird |title=Help Key: Why 120 Hz looks "weird" |accessdate=2009-11-13 |last=Biggs |first=John |date=August 12, 2009|publisher=crunchgear.com}}</ref>

Many complain that the soap opera effect ruins the theatrical look of [[Cinematography|cinematic]] works, by making it appear as if the viewer is either on set or watching a [[making-of|behind the scenes]] [[featurette]].<ref name="Vizio">{{cite web |url=http://ces.cnet.com/8301-13855_1-9845306-67.html |title=Vizio adds 120 Hz LCDs to its lineup |accessdate=2008-02-01 |last=Moskovciak |first=Matthew |date=January 8, 2008 |publisher=CNET.com}}</ref> Almost all manufacturers provide ways to disable the feature, but because methods and terminology differ, the [[UHD Alliance]] proposed that all televisions have a "Filmmaker Mode" button on remote controls to disable motion smoothing.<ref name="wouk20190921">{{Cite web |url=https://www.digitaltrends.com/home-theater/what-is-the-soap-opera-effect-in-tvs-and-how-to-turn-it-off/ |title=What is the Soap Opera Effect and how can you get rid of it on your TV? |last=Wouk |first=Kris |date=2019-09-21 |website=Digital Trends |archive-date=2020-01-31 |access-date=2020-01-31}}</ref>