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BERC Face Recognition Using Fisheye Camera Yonsei University Computer Visioin Lab. Jae Kyu Suhr
BERC
Face Recognition Using Fisheye Camera
Yonsei University
Computer Visioin Lab.
Jae Kyu Suhr
berc.yonsei.ac.kr
Flow Chart
Face detection using skin color
Radial distortion removing
Perspective distortion removing
Training face data enrollment
by pinhole camera
Test image acquisition by fisheye camera
Eigenface generation
Face normalization
Face recognition
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Training data acquisition and eigenface generation
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Training Data Acquisition
Face images of 51 subjects were acquired by Nikon digital camera and normalized them using positions of two eyes and mouth.
Normalization method
Resolution: 50×67 pixels (gray scale)Left eye : (15,24)Right eye: (31,24)Mouth : (23,40)
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Training image samples
Normalize
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Training faces and eigenfaces
Training images (51) Eigenfaces
Meanface
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Face detection
using foreground extraction and skin color
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Foreground Extraction
Background Foreground+Background
Background subtraction
Morphological process (closing)
Extracted foreground
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Skin Color-based Face Detection
Training face color
R G B
value
num
ber of pix
el
H S V
value
num
ber of pix
el
Y Cb Cr
value
num
ber of pix
el
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Skin Color-based Face Detection
Morphological process (closing)
Skin detection
Labeling Detection result
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Face Detection Results
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Two-Step
Distortion Removing
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1st step: Radial Distortion RemovingFisheye camera image Pinhole camera image
Equidistance projection model
er fθ=Perspective projection model
tanpr f θ=
tan( )ep
rr ff
=
Optical axis
Image plane
Incoming ray
Lensf
θ
rp
Image plane
Optical axis
Incoming ray
Lensf
θ
rp
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2nd step: Horizontal Perspective Distortion Removing
θ
Camera 1 Camera 2
-1 -11 2 2=KR K =Hx x x
x1 : image point on the image from camera 1
x2 : image point on the image from camera 2
K : camera intrinsic parameters matrix
R : rotation matrix
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Two Step Distortion Removing
Radial distortion Recticiation
Horizontal perspective distortion removing
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Experimental Environment
1.3m
0.5m1.0~2.2m Fisheye camera
Illuminator
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Test images
Enrolled face image
Input test images (height: 1.7m)
original rectified normalized
Input test images (height: 1.2m)
original rectified normalized
berc.yonsei.ac.kr
Test images
Enrolled face image
Input test images (height: 2.2m)
original rectified normalized
Input test images (height: 2.0m)
original rectified normalized
berc.yonsei.ac.kr
Test images
Enrolled face image
Input test images (height: 1.6m)
original rectified normalized
Input test images (height: 1.0m)
original rectified normalized
berc.yonsei.ac.kr
Test images
Enrolled face image
Input test images (height: 1.9m)
original rectified normalized
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Matching Result (rank 1)
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Matching Result (rank 2)
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Matching Result (rank 3)
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Failed Cases
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0.5m1m 2m
0.5m
Operating Range
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Thank youQ & A
