Shadow resistant tracking Ran Dror-Kita

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Shadow resistant tracking Ran Dror-Kita
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Tracking examples
JIANG DREW 2005
From Andrew Blake
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Why eliminating the shadow when tracking ?
Better recognition
Center of mass
separation
From PRATI et al 2001
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Outline
Snake tracker
Shadow snake
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Snaketracker
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Edge detection
Prewitt
gradient operators
DoG
Second derivative
sigma 1
sigma 2
sigma 3
Cannymethod
Images from Ruye Wang
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Boundary detection
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How to find the boundary ?What is a good
boundary ?
A good boundary is a line that fit best to more
edges.
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A good boundary is a line that fit best to more
edges.
How can we maximize E ?
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Gradient descent
Image from Teach/Me Data Analysis, Springer-Verlag
Climbing in the direction of the gradient
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Euler equations
For more Benjamin Svetitsky
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Euler Example
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example
surf(image)
image
plot(image(50,))
Gradient at the edge
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Created using the demo created by Chenyang
Xu,J.L. Prince and Dejan Tomazevic
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Bad example
Created using the demo created by Chenyang
Xu,J.L. Prince and Dejan Tomazevic
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Elastic energy
Minimizing the length of the contour. Like an
elastic rubber.
Length of the contour is
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The new energy
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The same examples again
Created using the demo created by Chenyang
Xu,J.L. Prince and Dejan Tomazevic
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All of the above from Snakes Active contour
models M. Kass, A. Witkin, and D. Terzopoulos
In Proc. 1st CCV, pages 259-268, June 1988.
London, UK
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Kass Witkin Terzopoulos 1988
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Lips tracking
Kass Witkin Terzopoulos 1988
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From Tim Smith
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The image force dont act on far points
Image force
image
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Gradient Vector Flow snake (GVF)
Traditional force
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GVF field performance
Traditional snake
GVF snake
GVF snake
Movies from Chenyang Xu and J.L. Prince
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examples
Highway
Heart
Images From Julien Jomier
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From Nikos Paragios Rachid Deriche
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From Andrew Blake
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3D example
3D Segmentation of the Hippocampus
From Julien Jomier
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Shadow Snake
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Shadow resistant tracking

1. Tracking Objects with Shadows, Hao Jiang and Mark
   S. Drew, Image and Video Communications and
   Processing 2003
2. Shadow Resistant Tracking using Inertia
   Constraints, Hao Jiang and Mark S. Drew, Pattern
   Recognition 2005, To appear

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System diagram
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Shadow invariant
planckian light
For the sensor G and this skin
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For specific camera and surface
Then (r,b) is an intrinsic of the surface.
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Shadow invariant
Removing Shadows from Images GD Finlayson, SD
Hordley, MS Drew - ECCV (4), 2002
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Camera calibration
Finding the dominant direction using PCA the
eigenvalues of the covariance matrix. (SVD of the
covariance matrix)
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How to measure the velocity of the boat when we
can only measure the height of the boat ?
Optical flow equation
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Optical flow
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Global motion compensation
Global motion is modeled by affine transformation

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Examples from Jiang Drew
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