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Video Textures. Arno Schödl Richard Szeliski David Salesin Irfan Essa Microsoft Research, Georgia Tech. Still Photos. Video Clips. Video Textures. Problem Statement. video clip. video texture. Approach. How do we find good transitions?. Finding Good Transitions.

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## Video Textures

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**Video Textures**Arno Schödl Richard Szeliski David Salesin Irfan Essa Microsoft Research, Georgia Tech**Problem Statement**video clip video texture**Approach**How do we find good transitions?**Finding Good Transitions**Compute L2 distance Di, j between all frames vs. frame i frame j Similar frames make good transitions**Markov Chain Representation**Similar frames make good transitions**Transition Costs**Transition from i to j if successor of i is similar to j Cost function: Cij = Di+1, j**Transition Probabilities**Probability for transition Pij inversely related to cost: high low **Preserving Dynamics**Cost for transition ij Cij = wkDi+k+1, j+k**Preserving Dynamics – Effect**Cost for transition ij Cij = wkDi+k+1, j+k**Deadends**No good transition at the end of sequence**Future Cost**• Propagate future transition costs backward • Iteratively compute new cost Fij = Cij + minkFjk**Future Cost**• Propagate future transition costs backward • Iteratively compute new cost Fij = Cij + minkFjk**Future Cost**• Propagate future transition costs backward • Iteratively compute new cost Fij = Cij + minkFjk**Future Cost**• Propagate future transition costs backward • Iteratively compute new cost Fij = Cij + minkFjk**Future Cost**• Propagate future transition costs backward • Iteratively compute new cost Fij = Cij + minkFjk • Q-learning**Finding Good Loops**• Alternative to random transitions • Precompute a good set of loops up front (using dynamic programming)**Visual Discontinuities**• Problem: Visible “Jumps”**Crossfading**• Solution: Crossfade from one sequence to the other.**Morphing**• Interpolation task:**Morphing**• Interpolation task: • Compute correspondencebetween pixels of all frames**Morphing**• Interpolation task: • Compute correspondence between pixels of all frames • Interpolate pixel position andcolor in morphed frame • based on [Shum 2000]**Results – Crossfading / Morphing**Jump Cut Crossfade Morph**Video Portrait**Useful for web pages**Video Portrait – 3D**Combine with IBR techniques**Region-based Analysis**• Divide video up into regions • Generate a video texture for each region**User-controlled Video Textures**User selects target frame range slow variable fast**Time Warping**Lengthen / shorten video without affecting speed shorter original longer**Summary**• Video clips video textures • define Markov process • preserve dynamics • avoid dead-ends • disguise visual discontinuities**Summary**• Extensions • regions • external constraints • video-based animation**Discussion**• Some things are relatively easy**Discussion**• Some are hard

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