?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=A+transformation-aware+perceptual+image+metric&rft.creator=Kellnhofer%2C+P&rft.creator=Ritschel%2C+T&rft.creator=Myszkowski%2C+K&rft.creator=Seidel%2C+HP&rft.description=Predicting+human+visual+perception+has+several+applications+such+as+compression%2C+rendering%2C+editing+and+retargeting.+Current+approaches+however%2C+ignore+the+fact+that+the+human+visual+system+compensates+for+geometric+transformations%2C+e.+g.%2C+we+see+that+an+image+and+a+rotated+copy+are+identical.+Instead%2C+they+will+report+a+large%2C+false-positive+difference.+At+the+same+time%2C+if+the+transformations+become+too+strong+or+too+spatially+incoherent%2C+comparing+two+images+indeed+gets+increasingly+difficult.+Between+these+two+extrema%2C+we+propose+a+system+to+quantify+the+effect+of+transformations%2C+not+only+on+the+perception+of+image+differences%2C+but+also+on+saliency.+To+this+end%2C+we+first+fit+local+homographies+to+a+given+optical+flow+field+and+then+convert+this+field+into+a+field+of+elementary+transformations+such+as+translation%2C+rotation%2C+scaling%2C+and+perspective.+We+conduct+a+perceptual+experiment+quantifying+the+increase+of+difficulty+when+compensating+for+elementary+transformations.+Transformation+entropy+is+proposed+as+a+novel+measure+of+complexity+in+a+flow+field.+This+representation+is+then+used+for+applications%2C+such+as+comparison+of+non-aligned+images%2C+where+transformations+cause+threshold+elevation%2C+and+detection+of+salient+transformations.&rft.subject=Image+metric%2C+Motion%2C+Optical+flow%2C+Homography%2C+Saliency&rft.publisher=Society+of+Photo-Optical+Instrumentation+Engineers&rft.contributor=Rogowitz%2C+BE&rft.contributor=Pappas%2C+TN&rft.contributor=de+Ridder%2C+H&rft.date=2015-04-10&rft.type=Proceedings+paper&rft.publisher=Human+Vision+and+Electronic+Imaging+XX&rft.language=eng&rft.source=+++++In%3A+Rogowitz%2C+BE+and+Pappas%2C+TN+and+de+Ridder%2C+H%2C+(eds.)+Human+Vision+and+Electronic+Imaging+XX.++(pp.+p.+939408).++Society+of+Photo-Optical+Instrumentation+Engineers+(2015)+++++&rft.format=text&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F1524336%2F1%2FKellnhofer%2520A%2520transformation-aware%2520perceptual%2520image%2520metric%2520CONF%2520PROC%2520VoR.pdf&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F1524336%2F&rft.rights=open