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A Prototype System for 3D Dynamic Face Data Collection by Synchronized Cameras. Yuxiao Hu Hao Tang. Problem Statement. Collect multi-view face video with expressions; Potential researches Co-articulation of facial expression and lip movement:
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A Prototype System for 3D Dynamic Face Data Collection by Synchronized Cameras Yuxiao Hu Hao Tang
Problem Statement • Collect multi-view face video with expressions; • Potential researches • Co-articulation of facial expression and lip movement: • Non-frontal view audio/visual speech recognition-lip reading
Relevant Works • Static 2D face databases: FERET, CMU PIE, ORL, Yale Database, UMIST, etc • Static 3D face databases: 3D-RMA, GavabDB, YorkDB, XM2VTS database, FRGC database,etc • 3D Dynamic face databases: • CMU FIA, no markers, no audio • Intel Research China Database, not synchronized
Highlights TotalSolution: Both hardware and software MultiView+Synchronization+RealTime Flexibility: Flexibly extended from 2 cameras to 5 cameras; Supplementary Tools: camera calibration, color space conversion, 2D facial feature tracking 3D face shape recovery
Physical Setup FoamHead
System Diagram Camera Calibration Video Data Capture Color De-mosaicing Facial Feature Tracking 3D Shape Reconstruction
Synchronization-Hardware Configuration DragonFly Camera
Synchronization-Software Implementation … Buffers … N Buffer Overrun? Buffer Overrun? Re-sync Y Y Y Time Stamp Matched? N AVI Y Compression
Offline Color De-mosaic Reconstructed RGB color image Raw Data: Color represented in Sparse (Stippled) Pattern Reconstructed RGB color video Raw Data
Camera Calibration • Find the intrinsic and extrinsic parameters • Use Camera Calibration Toolbox for Matlab • Two-step procedure • Find projection matrix using Direct Linear Transformation • Use as initialization for nonlinear minimization of mean squared re-projection error
Camera Calibration (cont’ed) Camera 1 Camera 2 Camera 1 Camera 2
Camera Calibration (cont’ed) Camera 1
Camera Calibration (cont’ed) Average re-projection error < 0.2 pixels (0.16279,0.13482) and (0.16439,0.12685) Camera 1 Camera 2
Facial Marker Tracking • Simple but effective tracking algorithm
Facial Marker Tracking (cont’ed) • Statistical marker collocation model
3D Reconstruction: Stereo Triangulation • A bit of theory
Deliveries • The data acquisition system of camera array • Tools for Color De-mosaicing • The calibration data and tools • Some sample data result • 3D ground truth data and labeling tool • Technical Report
Outline (4Ws+2Hs) • Why (do we do this?) • Who (has done the related work?) • What (we proposed to do?) • How (did we achieve our goal?) • Why (we need to do so?) • How (we evaluate our work?)