?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F749%2F&rft.title=Measuring+Vibrations+from+Video+Feeds&rft.creator=Brambley%2C+Ed&rft.creator=Fletcher%2C+Helen&rft.creator=Hill%2C+Roger&rft.creator=Johnston%2C+Ifan&rft.creator=Liu%2C+Jessie&rft.creator=MacKay%2C+Robert&rft.creator=Mathews%2C+J.&rft.creator=Ockendon%2C+John&rft.creator=Piette%2C+Bernard&rft.subject=Aerospace+and+defence&rft.description=By+using+a+high-speed+camera%2C+researchers+at+MIT+in+2014+where+able+to+recover+human+speech+from+videos+of+minute+vibrations+of+objects+in+a+room.+For+example%2C+in+one+experiment+a+2%2C200fps+camera+was+positioned+outside+a+room+behind+sound-proof+glass%2C+videoing+an+empty+crisp+packet+on+the+floor+inside+the+room%2C+while+a+researcher+shouted+%E2%80%9CMary+had+a+little+lamb%E2%80%9D+at+the+crisp+packet.+By+detecting+minute+oscillations+of+the+crisp+packet+of+1+%CE%BCm+(0.001+mm)%2C+and+using+hours+of+computer+processing%2C+a+ten+second+audio+clip+could+be+produced+that+was+recognisably+%E2%80%9CMary+had+a+little+lamb%E2%80%9D+in+an+American+accent.%0D%0AThe+purpose+of+this+study+group+was+to+investigate+whether+this+tech-+nique+could+be+used+in+practice%2C+with+emphasis+on+the+recovery+of+intel-+ligible+speech+from+a+video+feed+of+a+room.+During+the+week%2C+the+group+investigated+several+aspects+of+the+problem%2C+including%3A%0D%0A%E2%80%A2+how+much+an+object+vibrates+due+to+sound%3B%0D%0A%E2%80%A2+what+can+be+done+to+maximize+the+vibration%3B%0D%0A%E2%80%A2+how+the+MIT+technique+detects+minute+vibrations+in+videos%3B+%E2%80%A2+what+affects+the+quality+of+the+resulting+recording%3B+and%0D%0A%E2%80%A2+how+good+a+recording+is+needed+for+intelligible+speech.%0D%0AIt+was+discovered+the+MIT+experiments+would+not+have+recovered+intel-+ligible+speech+from+an+ordinary+conversation%3B+their+success+depended+on+loud+sounds+and+prior+knowledge+of+%E2%80%9CMary+had+a+little+lamb%E2%80%9D.+Camera+vibrations+were+also+ignored+by+MIT%3B+these+are+expected+to+be+signifi-+cant%2C+but+the+technique+could+be+adapted+to+be+resilient+to+them.+Other+possibilities+for+enhancing+their+technique%2C+by+exploiting+resonances+or+reflections%2C+are+discussed+in+the+report.+A+high-speed+low-noise+cam-+era+is+essential%2C+and+any+existing+video+footage+(such+as+from+CCTV)+is+unlikely+to+be+of+sufficient+quality.+Further+experiments+with+high-end+high-speed+cameras+are+needed+to+assess+the+feasibility+of+the+technique+in+practice.&rft.date=2017&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F749%2F1%2Fmod_report.pdf&rft.identifier=++Brambley%2C+Ed+and+Fletcher%2C+Helen+and+Hill%2C+Roger+and+Johnston%2C+Ifan+and+Liu%2C+Jessie+and+MacKay%2C+Robert+and+Mathews%2C+J.+and+Ockendon%2C+John+and+Piette%2C+Bernard++(2017)+Measuring+Vibrations+from+Video+Feeds.++%5BStudy+Group+Report%5D+++++