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Resynthesizing Facial Animation through 3D Model-Based Tracking. Frédéric Pighin 1 Richard Szeliski 2 David Salesin 1,2. 1 University of Washington 2 Microsoft Research. Goals. Overall: Generate photorealistic facial animation. In this paper:
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Resynthesizing Facial Animation through 3D Model-Based Tracking • Frédéric Pighin1 Richard Szeliski2 David Salesin1,2 1University of Washington 2Microsoft Research
Goals • Overall: • Generate photorealistic facial animation. • In this paper: • Track face position & expression in video. • Generate novel animation from tracked data.
Applications • Editing faces in video: • Lighting • Camera angle • Facial alterations (tattoos, scars, makeup) • Performance-driven animation: • Virtual actors & user-interface agents • Chat-room avatars • Home-made animation
Approach [SIGGRAPH 98] • Use images to adapt a generic face model.
Input images Face modeling example
Face modeling example, cont. Modeling results
Creating new expressions New expressions are created with 3D morphing: • Applying a global blend + = /2 /2
Creating new expressions, cont. • Applying a region-based blend + = x x
Creating new expressions, cont. • Using a painterly interface + + + =
Animating between expressions Morphing over time creates animation: “joy” “neutral”
Tracking the face • We use the 3D texture-mapped models as a basis for fitting the face. • The face is split into 3 regions: • For each frame, we track: • Position & orientation • Expression for each region
Model fitting • Let p be the model parameters: • p = (position, orientation, expression). • We use a Levenberg-Marquardt algorithm to minimize an error function: • The penalty constrains the search to realistic facial expressions.
Model fitting, cont. • The best fits were found using: • An analytical Jacobian for position & orientation parameters. • Finite differences for expression parameters. Pose estimate Expression estimate RMS error
Tracking results • Tracked faces Original video frames
Editing: Change of viewpoint Original New viewpoint
Editing: Exaggerating expression Fitted model Original Exaggeration
Editing: Changing the lighting Lit model Original Relit
Editing: Adding tattoos Rendered tattoo Synthetic tattoo Original
Performance-driven animation Original Same expression on new face
Conclusion • Photorealistic facial animation via: • Image-based modeling & rendering • 3D morphing • Pose & expression tracking via: • Analysis by synthesis • Applications include: • Editing (change of viewpoint, lighting, etc.) • Performance-driven animation