1. The Cartoon Animation Filter Jue Wang Steven Drucker Maneesh Agrawala Michael Cohen

2. The Cartoon Animation Filter Goal –Add “liveliness” to any motion signal Should be –Simple –General –As automated as possible –Fast enough for real-time interaction

3. A very boring animation

4. x * (t) = x(t) + x ’’ (t) * - x’x’ time x x ’’ -x ’’ -x ’’ + x -x ’’, x Anticipation Follow-through

5. An almost as boring animation

6. x * (t) = x(t) + x ’’ (t) * - x * (t) = x(t) + x (t) * - ’’ -LoG

7. Convolution with -LoG Error in equation (2): x * (t) = x(t) * -LoG x * (t) = x(t) + x(t) * -LoG

8. -LoG Parameters Amplitude – user set Width (frequency) – automatically set [later] 

9. Image Sharpening

11. Demo 3 Show ball with vectors forward and backward Show 3 copies of curve, original and time shifted forward and back Convolve Show squash and stretch ball again

12. Squash and Stretch x ’’ LoG p (t) = LoG(t+  t)  t ≈ x ’’ · p p

13. Squash and Stretch time x ’’ Volume Preservation –Inversely stretch/squash orthogonally to acceleration

14. Squash and Stretch

15. Spin Show spin

16. Related Work Physically Based, lots Stylized, e.g., Chenney et al. 2005, Igarashi et al. 2002 Surface Deformation, lots… Signal Based, e.g., –Unuma et al. 1995, –Bruderlin and Williams, 1995 Video Paintbox, Collomosse 2004 Motion Magnification, Liu et al. 2005

17. Livening Up Powerpoint

19. Enhancing Video Objects

21. Need to maintain constraints –Simplest approach –Move figure in each frame vertically to keep feet/skateboard in place

22. Enhancing Video Objects

27. Golfswing Apply filter to each DOF independently What should the filter width be?

28. Setting LoG Width  *( t ) = max   |X(  )|   *( t ) = max   | F ( x ’ ( t ))|  ( t ) = 2  /  *( t ) time  original fixed  adaptive  (over 32 frame window)

29. Walking

30. Boxers

33. Demo Realtime amplitude adjustment - mocap

34. Discussion (Almost) fully automated –NOT a tool for experts –But may make good first cut Need better constraint maintenance –IK, physical constraints Online (in-game) usage –Single animation adjusts to situation

35. Where from here? Make a kid’s animation system