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3D Face Reconstruction from Monocular or Stereo Images. . Thomas Vetter. Universit y of Basel. Switzerland . http://gravis.cs.uni bas.ch. Change Your Image . Analysis by Synthesis. model parameter. Analysis. Image Model. Synthesis. Image. 3D World.
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3D Face Reconstruction from Monocular or Stereo Images. Thomas Vetter University ofBasel Switzerland http://gravis.cs.unibas.ch
Analysis by Synthesis model parameter Analysis Image Model Synthesis Image 3D World Image Description
Approach: Example based modeling of faces 2D Image 3D Face Models 2D Image 2D Face Examples = w1 * + w2 * + w3 * + w4 * +. . .
Morphing 3D Faces 1 __ 2 3D Blend 3D Morph 1 __ = + 2
Shape and Texture Vectors Reference Head Example i
Registration in different representations • Curvature Guided Level Set Registration using Adaptive Finite ElementAndreas Dedner, Marcel Lüthi, Thomas Albrecht and Thomas Vetter IN: Proceedings DAGM'07: Heidelberg 2007 • Optimal Step Nonrigid ICP Algorithms for Surface RegistrationBrian Amberg, Sami Romdhani and Thomas Vetter IN: Proceedings, CVPR'07, Minneapolis, USA 2007. • A Morphable Model for the Synthesis of 3D Faces. Volker Blanz and Thomas VetterIN: SIGGRAPH'99 Conference Proceedings, 187-194 • Implicit: • Triangulated: • Parameterized:
Vector space of 3D faces. • A Morphable Model can generate new faces. a1 * + a2 * + a3 * + a4 * +. . . = b1 * + b2 * + b3 * + b4 * +. . .
Manipulation of Faces Modeler
Continuous Modeling in Face Space Caricature Original Average Anti Face
Modelling the Appearance of Faces A face is represented as a point in face space. • Which directions code for specific attributes ?
Learning from Labeled Example Faces Fitting a regression function
Facial Attributes Weight Subjective Attractiveness Gender Original
3D Shape from Images Face Analyzer Input Image 3D Head
Matching a Morphable 3D-Face-Model • R = Rendering Function • = Parameters for Pose, Illumination, ... Find optimal a, b, r !
Automated Parameter Estimation Ambient: intensity, color Parallel: intensity, color,direction Color: contrast, gains, offsets • Face Parameters • 150 shape coefficients ai • 150 texture coefficients bi head position head orientation focal length • 3D Geometry • Light and Color
Image Formation: at each Vertex k • Rigid Transformation • Normals • Phong Illumination • Perspective Projection • Color Transformation • bi • ai
Error Function • Image difference (pixel intensity cost function) • Plausible parameters • Minimize
Which Feature to use? someEdge detector
Edge Feature • Rigid Transformation • Normals • Phong Illumination • Perspective Projection • Color Transformation • bi • ai
Multi-Features Fitting Algorithm 1 2 3 4 5 At stage 4:
Recognition from Images Complex Changes in Appearance Images: CMU-PIE database.
Correct Identification “1 out of 68” (%) • 99.5 • 83.0 • 97.8 • 86.2 • 79.5 • 85.7 • 92.3 • 95.0 • 89.0 • gallery • front • side • profile • probe • front • 99.8 • side • 99.9 • profile • 98.3 • total CMU-PIE database: 4488 images of 68 individuals 3 poses x 22 illuminations = 66 images per individual
Reanimation of Images V. Blanz, C. Basso, T. Poggio & T. Vetter Reanimating Faces in images and Video Proc. of Eurographics 2003
Expression Transfer Fitting Fitting Rendering
Analysis by Synthesis model parameter • Image Processing • Edges • Highlights • Segmentation • …… Image Model some ║ ║X Analysis Synthesis 3D World Image Description Image
Segmenting hair a general requirement ? No outlier detection with outlier mask
Skin segmentation • We need to mask out non-skin regions / outliers • 3DMM is not sufficient
Shading Problem • Skin regions contain strong intensity gradients that make a segmentation difficult!
Illumination Compensation • Skin Detail Analysis for Face RecognitionJean Sebastian Pierrard , Thomas Vetter CVPR 2007 Local fitting
Segmentation Results GrabCut • Skin Detail Analysis for Face RecognitionJean Sebastian Pierrard , Thomas Vetter CVPR 2007 Thresholding
Try New Hairstyles 3D Angle, Position Illumination, Foreground, Background 3D Shape and Texture
More Hairstyles 3D Shape and Texture 3D Angle, Position Illumination, Foreground, Background
Using more than a single image ? Reconstructing High Quality Face-Surfaces using Model Based Stereo Brian Amberg, Andrew Blake, Andrew Fitzgibbon, Sami Romdhani and Thomas Vetter IN: Proceedings ICCV 2007 Rio de Janeiro, Brazil
Results on Flash Data Ground Truth Monocular Stereo