All that video! Analysis Across Time, Place, & Activities

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All that video! Analysis Across Time, Place, & Activities Slide 2 The Problems Too much video Too little time Too few people Too many hypotheses Hard to search through video Slide 3 Slow Coding Slide 4 Why so Much? Timescales of phenomena of interest Weeks, months, years of video Following people across sites & activities Comparative cases multiply video footage Video is becoming cheap and easy Storage and processing is feasible Slide 5 New Hope for the Dread Winnow footage to identify useful segments Speedview through footage Simultaneous multiple video displays Time sampling Multiple timescale viewing (temporal zoom) Place synthesis (multiple viewpoints) Computational search and classification Slide 6 Time Sampling Randomly sample with a fixed-length time window Sample every n seconds for fixed time Catenate the samples and run as a meta-video Cf. time-lapse and stroboscopic photography What makes a sample representative? Criteria for helpful sampling? Slide 7 SpeedViewing What do we see if we watch a lot of video at accelerated speed? With or without time-sampling Manovich group NBC News meta-video: time- sampled to just opening scenes, collected for 20 years, run as a single video Pattern recognition? Aided by comparison? Slide 8 Overlay-viewing Slide 9 Side by Side Slide 10 Multiple Comparisons We are a bit used to watching two related videos side by side What if there were a display matrix of 4? Or 9, in a 3-by-3 array? All running simultaneously, in synch What would we notice? How would we learn to watch such displays? Slide 11 Time Zoom Not side-by-side in space, but nested in time Along a timeline of the long scale of a video or several chained together, Expand an inner timeline of an embedded episode, And within that one, another Perhaps down to individual frames Slide 12 Scrolling timescales Slide 13 Place Across Time Microsoft PhotoSynth assembles composite spaces from large sets of photographs of same or adjacent scenes from different viewpoints http://photosynth.net/ http://photosynth.net/ If the images were video stills from one or more traversals through a neighborhood, a composite image could index the videos spatially And allow us to search a video corpus spatially, With or without GPS markup Slide 14 Computational Screening Recent advances in computer science support scene recognition in video (TRECVID) Image and video classification Find more like these Identify similarity/difference clusters Even with many false positives, aids manual segment selection for further analysis Slide 15 Image classification Slide 16 Clustering Faces Slide 17 Context Browsing Slide 18 Multi-thread Browsing Slide 19 Reductive Comparison Slide 20 The Meaning Problem Maintaining a focus on meaning makes the big picture hard to see and the analysis of large databases of rich media intractable Postponing a focus on meaning allows us to benefit from the rich redundancy of media features to let computation aid selection Meaning enters when we select criterial features of interest to guide computation and when we interpret its results afterwards Slide 21 A New Paradigm? Mixed and Complementary Methods to combine Qualitative & Quantitative paradigms Abandon the logic of Experimental research on complex socio-natural systems (neither control nor generalizability is achievable) Keep quantitative methods for data mining qualitatively rich media databases Keep and extend Qualitative paradigms to ground the logic of research