advanced recognition system
TRANSCRIPT
Motivation
• Database in Varying Pose• Lack of Illumination• Glasses Interferences
• Database in Larger scale
Drawback • Time Consuming• Varying Pose and Illumination • Frontal Views/Face Expression and Disguise
Brief Analysis of the Database and the Original System • Good Illumination • Varying Pose (Tilted Face )• NOT Only the Frontal Views
Build Face Part Detector/Crop the Face• Output the Face Boundary, Left eye Boundary, Right eye Boundary,
Mouth Boundary and Nose Boundary
• The relevant information is included in the documentation of Matlab, vision.CascadeObjectDetector System object.
The Second Type• Get Vertical Center of Mouth and Nose • Calculate Absolute Distance of Two Middle Lines • ‘Relative’ Distance • Set Threshold
• Check Location of Left Eye&Right Eye (the boundary box)• Get Center points• Link • Check the Angle • imrotate() • Rebuild Face Part Detector&Recrop the Face
Detect If It Is Tilted Face
Illumination-Correction • • Low Frequency Component & High Frequency Component • DCT Normalization (Discrete Cosine Transform Normalization)•
K. P. Horn, Robot Vision. Cambridge, MA: MIT Press, 1986.
Details• Installation • Do Image Histogram Normalization • Create & Save Zigzag Map • Transform to Logarithm & Frequency Domains• Set Zero to the Relevant Coefficient• Inverse DCT • Post-Processing
Recover Masked Skin• Get mean within 5*5 box• Special case:• Not only one pixel in box• Recursively find the other pixels’ mean
Skin Color Detection:
Lighting Compensation
Color Transformastion
Skin Color Detection Variance-based Segmentation
Component Grouping
Face Boundary Detection
Main Work • Delete Side-face• Crop Face• Tiled-face Rotation• Illumination Correction• Glasses Removal • Properties Analysis