HDR Aymeric Histace vpdf

Nov 28, 2014 - Electrical Engineering, Energy, Control (L1, L2+L2 app, L3P). Image Processing (Basic .... System. Coherent signal. (Input). Noise. Output.
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Contribu8ons  to  Image  Processing   For  Medical  Image  Analysis   From  Computer-­‐Aided-­‐Diagnosis  to   Embedded  Systems  For  In  Situ   Diagnosis   TODAY YESTERDAY

Aymeric Histace HDR Defense

TOMORROW

28-11-2014

Roadmap   •  General  Presenta+on     •  Who  am  I?  

•  Research  Ac+vi+es      

•  What  are  my  contribu3ons?  

•  Perspec+ves   •  What  is  my  research  project?   28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

2  

Roadmap   •  General  Presenta+on     •  Who  am  I?  

•  Research  Ac+vi+es      

•  What  are  my  contribu3ons?  

•  Perspec+ves   •  What  is  my  research  project?   28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

3  

Who  am  I?  

CV  

Certificate of Birth •  4th Sept. 1977, Lyon •  Parents: B. Histace and D. FerreyreHistace

1977

2001

2001

2004 PhD

MSc Master of Engineering •  EIGSI La Rochelle •  Industrial Systems Engineering

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•  Signal and Image in Biology and Medecine

•  “Detection and tracking of structure in image sequences: application to tagged cardiac MR images”

•  University of Angers

•  Mention: “Très Honorable avec les félicitations du jury”

•  Wavelet Compression of Thoravision images (X)

•  University of Angers

Aymeric  Histace  -­‐  HDR   Defense  

4  

Who  am  I?  

Professional  Experience   2001

2004

PhD, “Moniteur”

2013 28/11/14

2006 Lecturer

Associate Professor (UCP, ETIS) PES

TODAY

Research •  Member of ASTRE team •  In charge of the “Embedded Systems for Health” axis •  Elected Member of the Laboratory Council

28/11/14  

Teaching Administrative •  Co-Head of MSc MADOCS (Methods for Complexe Data Analysis)

Aymeric  Histace  -­‐  HDR   Defense  

•  Institute of Technology •  Dpt of Electrical Engineering and Industrial Informatic (GEII) •  Member of the “Commission de choix”

5  

Who  am  I?  

Teaching  and  Responsabili8es  

Sept 2004 2006

IUT GEII

28/112014

Electrical Engineering, Energy, Control (L1, L2+L2 app, L3P)

MSc

Sept 2007

Image Processing (Basic, Variationnal approach, Statistical Learning) Lecturer, University of Angers

Sept 2010 L2 app (08-14): Industrial relationships and pedagogical coordination

L3P Instru. (07-08) 2007

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2008

ENSEA

Signal Processing for ECG (ENSEA) Sept 2013 MSc SIC (11-14): Electronics for Biosensors CMI Pedagogical Coordination « Multimedia Indexing …L3P ESH MSc and Data Mining » MADOCS 2011 2012 >2014

Aymeric  Histace  -­‐  HDR   Defense  

6  

Who  am  I?  

Research  Overview  

Next Step

Step 1

1 Noise rms

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Aymeric  Histace  -­‐  HDR   Defense  

18  

In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Application to Image Restoration Gaussian noise

Objectives : •  Noise reduction •  Contour integrity No

Method

# I(x, y, 0) = I 0 % $ ∂I %& = div gη ( ∇I ) ∇I ∂t

(

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with

)

gη (u ) = g (u + η ( x, y )) Stochastic Variant of Perona-Malik process

Aymeric  Histace  -­‐  HDR   Defense  

Yes

•  η a noise assumed independent and identically distributed (rms amplitude ση) •  g a decreasing monotonic function 19  

In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Experiment 1

gη (u) = g(u + η (x)) with

We consider a case where k parameter is badly tuned regarding PM approach : (left) Original noisy contour

⎧1 if s ≥ k g ( s) = ⎨ ⎩0 if s  k

(right) Restored one using PM approach with k=0.6

Hard-threshold

Result S-PM

Purposely injection of η noise in g function can randomly retune the function PM PM

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S-PM

Aymeric  Histace  -­‐  HDR   Defense  

20  

In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Experiment 2

gη (u) = g(u + η (x)) with

We consider a case where k parameter is badly tuned regarding PM approach : (left) Original noisy contour

⎧1 if s ≥ k g ( s) = ⎨ ⎩0 if s  k

(right) Restored one using PM approach with k=0.6

Hard-threshold

Result

(Quantification)

Variation of the ratio of well restored function of the noise rms amplitude (1000 attempts). The non-diffusion ratio is maximum for a non zero amount of noise

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Aymeric  Histace  -­‐  HDR   Defense  

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In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Extension to image restoration Gaussian Noise (PM, S-PM)

# I(x, y, 0) = I 0 % $ ∂I %& = div gη ( ∇I ) ∇I ∂t

(

with and

)

gη (u ) = g (u + η ( x, y )) g (u ) = e



u

2

k2

Multiplicative Noise (PM, S-PM)

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Impulsive Noise (PM, S-PM)

Aymeric  Histace  -­‐  HDR   Defense  

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In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Result (quantification) Normalized Cross Covariance wrt the amount of injected noise (1000 attempts)

Question 1: Answer Gaussian Multiplicative Impulsive

In each case the similarity measure is maximum for a non-zero amount of injected noise Elec. Letters 2006, PSIP 2007, IEEE SocPar 2010, Int Journal of Comp .Infor. Systems and Industrial Management 2012

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Aymeric  Histace  -­‐  HDR   Defense  

23  

And  Then…  

CAD:  Main  Contribu8ons

 

Stochastic Resonance Non-Linear PDE ∂I = div gη ( ∇I ) ∇I ∂t

(

)

Active Contour With Shape Prior E = E prior + Eimage

ChanVese

Alpha-Divergence Based Active Contour

E = Ehistogram + Eregularisation

Shape learning

Shape descriptor (Legendre)

gη (u ) = g (u + η ( x, y ))

Gaussian Noise

Coll. CREATIS David Rousseau

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Up : Foulonneau, Down : Our Approach Coll. UCLan B. Matuszewski

Aymeric  Histace  -­‐  HDR   Defense  

Joint Optimization: -Segmentation Process -Metric of the divergence Coll. I3S PhD Leila Meziou

24  

In  Details:  Segmenta8on  

Ac8ve  Contours

 

Principle

Ω = Ωin ∪ Γ ∪Ωout

Gradient-based approach:

E(∂Ω) =

!

min ( Eimage + Eregularisation +...) 28/11/14  

∫ k (x, y)ds b

∂Ω

Region-based approach:

E(Ωi ) =

Aymeric  Histace  -­‐  HDR   Defense  

∫ k (x, y, Ω )ds b

i

Ω

25  

In  Details:  Ac8ve  Contour  

Shape  Prior  

Cardiac MRI

Main Idea •  In Medical Image, the shape of the structure to segment is often “known” •  Question: Knowing the “mean” shape of an object, can we integrate it in an AC segmentation process ?

SA

LA

Microconfocal images

X-Ray Radiography (hip bone)

Proposal

( )

( )

( )

E λr = E prior λr + Eimage λr 28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

with λr a reduced shape descriptor (statistical learning) 26  

In  Details:  Ac8ve  Contour  

Shape  Prior  

Shape Space Representation Shape descriptor

Statistical Learning (PCA)

Shape Ω

Moments

λi

Test image N0

such as N0 = 5

∑λ

i

i=1 N 0 = 20 N 0 = 40 The chicken image set used to build the statistical shape model

Zernike moments

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Legendre moments

1 λ= NS

Aymeric  Histace  -­‐  HDR   Defense  

NS

∑ i =1

1 λi Q = NS

NS

∑ (λ i =1

T

i

− λ )( λ i − λ )

λ r ,i = P T ( λ i − λ )

27  

In  Details:  Ac8ve  Contour  

Shape  Prior  

Shape Space of Moments Eigen Shapes

How it works

( )

( )

( )

E λr = E prior λr + Eimage λr Final Result

NS

NS

p ( λ r ) = ∑ N ( λ r ; λ r ,i , σ 2 )

p ( λ r ) = ∑ N ( λ r ; λ r ,i , σ 2 )

i =1

i =1

λ = λr ,1 ⋅ p1 + λr ,2 ⋅ p2 + λ

⎛ N S 2 ⎞ E prior ( λ r ) = − ln ⎜ ∑ N ( λ r ; λ r ,i , σ ) ⎟ ⎝ i =1 ⎠

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Iterations shown in the feature space spanned by the first two principal axes

Aymeric  Histace  -­‐  HDR   Defense  

Different from Template Matching

28  

In  Details:  Ac8ve  Contour  

Shape  Prior  

Results 1 (Legendre Moments)

Chan-Vese method

Multi-reference shape prior method (Foulonneau 09)

The proposed method

Original binary image

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Image with Gaussian noise

Image with structural noise

Image with Gaussian and structural noise

Aymeric  Histace  -­‐  HDR   Defense  

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In  Details:  Ac8ve  Contour  

Shape  Prior  

Results 2

Question 2: Answer 1

CAIP 2011, Journal of Mathematical Imaging and Vision 2013

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Space Shape of Legendre Moments makes possible Shape Prior integration different from template matching

Aymeric  Histace  -­‐  HDR   Defense  

30  

And  Then…  

CAD:  Main  Contribu8ons

 

Stochastic Resonance Non-Linear PDE ∂I = div gη ( ∇I ) ∇I ∂t

(

)

Active Contour With Shape Prior E = E prior + Eimage

ChanVese

Alpha-Divergence Based Active Contour

E = Ehistogram + Eregularisation

Shape learning

Shape descriptor (Legendre)

gη (u ) = g (u + η ( x, y ))

Gaussian Noise

Coll. CREATIS David Rousseau

28/11/14  

Up : Foulonneau, Down : Our Approach Coll. UCLan B. Matuszewski

Aymeric  Histace  -­‐  HDR   Defense  

Joint Optimization: -Segmentation Process -Metric of the divergence Coll. I3S PhD Leila Meziou

31  

In  Details:  Ac8ve  Contour  

Alpha-­‐divergence  

Histogram-Based Active Contour

E = Ehistogram + Eregularisation

Probability density function

Divergence

D ( p1 || p2 , Ω) =

∫ ϕ ( p , p , λ )d λ 1

2

with

ℜm

" ϕ a similarity function $ pi the pdf of Ωi # $ $% λ the quantization level

Questions: •  How to model the pdf pi (derivation constraints)? •  Which φ function? 28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

32  

In  Details:  Ac8ve  Contour  

Alpha-­‐divergence  

Histogram-Based Active Contour pdf modeling

Divergence

(Parzen Window)

Usually

pˆ i ( λ, Ωi ) =

1 Ωi

∫ g ( I(x) − λ ) dx σ

Ωi

with gσ a Gaussian kernel of variance σ

28/11/14  

•  Kullback-Leibler •  Hellinger •  Ki2

α={0,1} α=0.5 α=2

Our proposal •  Alpha-divergence

Aymeric  Histace  -­‐  HDR   Defense  

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In  Details:  Ac8ve  Contour  

Alpha-­‐divergence  

Joint Optimization Maximization of the divergence

Optimization of alpha-parameter

argmax Γ ( Dα ( pin || pout , Ω))

argmaxα ( Dα ( pin || pout , Ω))

$ ∂α & = −∂Dα ( pin || pout , α ) & ∂t % & ∂Γ = −∂ pin , pout Dα ( pin || pout , α ) &' ∂t 28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

Algorithm 1.  αt+1 (αinit = 1) 2.  Γt+1 34  

In  Details:  Ac8ve  Contour  

Alpha-­‐divergence  

Result 1 (Synthetic images)

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In  Details:  Ac8ve  Contour  

Alpha-­‐divergence  

Result 2 (Synthetic images)

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Aymeric  Histace  -­‐  HDR   Defense  

36  

In  Details:  Ac8ve  Contour  

Alpha-­‐divergence  

Result 3 (Natural Images) Microconfocal images of cells

Question 2: Answer 2 Alpha-divergence are a flexible tool to cop with different noise scenarios in medical image analysis (but not only)

Videocapsule (coloscopy)

X-Ray images

ICIP 2011, ICASSP 2012, MIUA 2012 (Best Student Paper Award), Annals of BMVA 2013, ICIP 2014

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Aymeric  Histace  -­‐  HDR   Defense  

37  

CAD  to  in  situ  Diagnosis   Energy

Interaction

Computation

Size

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2011-­‐>2014:  CAD  to  In  Situ  Diagnosis  

Cyclope  Project

 

Main idea (induced by Question 3) To develop a smart autonomous videocapsule with embedded image processing capabilities

In situ detection of intestinal pathologies

Polyp

Ulcer

Angioma 28/11/14  

Chrone disease Aymeric  Histace  -­‐  HDR   Defense  

Colorectal Cancer 39  

2011-­‐>2014:  CAD  to  In  Situ  Diagnosis  

Cyclope  Project

 

Main idea (induced by Question 3) To develop a smart autonomous videocapsule with embedded image processing capabilities

Context

polyp

Colorectal Cancer 28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

Advantages

Drawbacks

• 

Total control

• 

Anaesthesia

• 

Possibility of biopsy's

• 

Hospitalization

• 

Real-time analysis

Advantages

Drawbacks

• 

Painless

• 

Battery life

• 

No sedation

• 

Low resolution

• 

No hospitalization

• 

No control

• 

Just swallow it!

• 

~150k images

40  

2011-­‐>2014:  The  Cyclope  Project  

The  Cyclope  Pill

 

A Multispectral WCE

Infrared (Active Stereo Vision)

3D feature-based detection

Visible

28/11/14  

2D feature based detection

Aymeric  Histace  -­‐  HDR   Defense  

41  

2011-­‐>2014:  The  Cyclope  Project  

2D  Detec8on  (Compa8ble     With  Embedding  Constraints)  

Gray-­‐level   Image  

Edge   detec8on  

Hough   Transform  

ROI extraction

Learning by boosting Training   examples  

Classifiers  

Co-occurrence matrix (26 features)

Feature   extrac8on   (Texture)  

Candidate Polyps Database : 300 Positives examples, 1200 Negatives ones

28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

42  

2011-­‐>2014:  The  Cyclope  Project  

2D  Detec8on   Results and Performance

28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

43  

2011-­‐>2014:  The  Cyclope  Project  

2D  Detec8on   Results and Performance (Real Time Tracking) Question 3: Answer It is possible to design low complexity detection/recognition algorithms in accordance with: (i) embedding constraints, and (ii) expected performance Bernal 88% 91%

Our Approach 99% 95%

1% 5% DCIS 2012, IEEE EMBC 2013, GRETSI 13, International Journal of Computer Assisted Radiology and Surgery, 2014

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Sensibility

Aymeric  Histace  -­‐  HDR   Defense  

Specificity

False Positive Rate

44  

Synthesis  of  contribu8ons   2005

28/11/2014

From CAD…

Question 1 •  Stochastic Resonance •  Non-linear PDEbased image restoration process •  Double Well potential 28/11/14  

…to in situ Diagnosis

Question 2 Active contour with: •  Shape Space moments •  Alphadivergence •  Fractional entropy

Aymeric  Histace  -­‐  HDR   Defense  

Question 3 •  Early Detection of Colorectal Cancer •  Real-Time tracking of colonic polyps •  In Situ Diagnosis

45  

What  are  my  contribu8ons?  

Related  Publica8ons  

(2006-­‐2014)  

9 Journals, 1 Patent: PRL*, JMIV*, EL*, IJCARS*+, IJBI+, Annals of BMVA,…

12   10   8  

28 Int. Conferences: ICIP, ICASSP, CAIP, EMBC, MIUA, CARS,…

6   4   2   0  

2010  2011  2012  2013  2014  

Indexed by JCR + Indexed by PubMed *

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Others:

Journals,  Patents  

3 Book Chapters, 1 Book Editing, 1 Proceeding Editing, 6 National Conferences (GRETSI)

Inter.  Conf.  

Aymeric  Histace  -­‐  HDR   Defense  

Others  

46  

Roadmap   •  General  Presenta+on     •  Who  am  I?  

•  Research  Ac+vi+es      

•  What  are  my  contribu3ons?  

•  Perspec+ves   •  What  is  my  research  project?   28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

47  

Research  Ac8vi8es-­‐Evolu8on

 

ECSON, TERAFS, SIMBAD

Cyclope In Situ Diagnosis

CAD

Signal and Image Processing

Embedded Systems

Smart-Aided Diagnosis Medecine - Biology

Electronic, Data-Base

Understanding of Living mechanisms

e-diagnosis SmartEEG PAPILLON

FibroSES iFib

28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

48  

…and  The  Story  Does  Not  End  

Research  Project     (Short  and  Mid  Terms)

Image Processing / Pattern recognition Electronics, Embedded Systems

Alpha-Divergence in Pattern Detection

Electrical Characterization of Fibrosis Induced by Implants

•  Collaboration with D. Rousseau (CREATIS Lyon)

•  IMS, INL, LIP6, ERRMECe

Smart-Videoendoscopy •  PhD of Quentin Angermann •  SATT •  Evolucare Medical Imaging Cell shape characterization

Smart EEG •  LIP6, INL, SME Cyclope •  H2020 Project (Greece, Switzerland, UK, Spain, France, Belgium)

•  Collaboration with UCLan and UB

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Aymeric  Histace  -­‐  HDR   Defense  

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Long  term  

Research  Project   Cellular level TERAFS, iFib, FibroSES

ECSON, SIMBAD

Cyclope

Image processing

Fluorescence

RF Physiological data

Localization

NAUTILES (H2020)

SmartEEG NeuroCOM (ANR) SPOT (FUI)

CyberPill

Drug Treatment

Nanoparticles

Control

28/11/14  

NAUTILES (H2020)

Aymeric  Histace  -­‐  HDR   Defense  

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THANKS TO THEM Q. Angermann (2014-…), C. Azib (2013), E. Bonnefoye (2012), M. Breuilly (2009), N. Cazin (2014), M. Degaudez (2007), M.-C. Desseroit (2013), H. Diouane (2014), C. Fouquet (2011-2014), M. Garnier (2009, 2011), C. Georgel (2013), M. Ibouchichene (2014), A. Izard (2013), L.-A. Latchimy (2013), T. Longret (2013), L. Meziou (2010-2013), S. Mouzai (2014), C. Nzuzi (2013), M. Rémignon (2014), A. Riaz (2013), H. Saidi (2014), J. Silva-Quintero (2012), A. Sittadannam (2014), Y. Zhang (2009-2010).

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THANK YOU FOR YOUR ATTENTION

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Aymeric  Histace  -­‐  HDR   Defense  

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Aymeric  Histace  -­‐  HDR   Defense  

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Research  Project   From  Nano  to  Macro  

Mathematics

Biology

Imaging Technic

Signal and Image Processing

Electronic

To understand manifestations of a same pathologic phenomenon from cell to organ scales (even nano) and draw some possible connections 28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

54  

Synthesis  

• 

In charge of the SES axis of ASTRE team

• 

Elected member of the Research Council of ETIS

• 

8 research projects

• 

Co-head of MSc MADOCS

• 

Active inter. and Nat. Collaborations

• 

Different types of experiences (IUT, UCP)

• 

8 Journal papers, 28 Int. Conf.

• 

2 defended PhD, 2 on-going

2006-2014

• 

L1, L2, L3, MSc, ENSEA

• 

Interaction Teaching/ Research

• 

In charge of the industrial relationship (2008-2014)

28/11/14  

And what about the future now ? Aymeric  Histace  -­‐  HDR   Defense  

55  

Snapshot  

Today-­‐Teaching     •  Neuville  In+tute  of  Technology,  UCP,  ENSEA   Students  

Classes  

Lecture  and  Tuto  (h)   Labs  (h)  

1st  year  (L1)  

Electrical  Engineering  and  Energy  

32  

2nd  year  (L2)  

Electrical  Engineering  and  Energy    

   

48  

2nd  year  (L2)  

Control  Theory  

28  

2nd  year  App.  (L2)  

Control  Theory  

54  

Prof.  Licence  (L3)  

Electrical  Engineering  and  Energy    

30  

MSc  SIC  

Image  Processing  

15  

MSc  MADOCS  

Sta8s8cal  Learning  

6  

ENSEA  3rd  year  (EIB)  

Signal  Processing  for  ECG  

6  

 

Total  

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171  

Aymeric  Histace  -­‐  HDR   Defense  

32  

80  

56  

Snapshot  

Today-­‐Supervising

 

Synthesis  

3 PhD students: 120%+50% •  2 Defended (11/2013, 06/2014) •  1 just started (50%)

17%  

25%   PhD   MSc  

7 MSc students: 330% •  MSc SIC, ESA

Others   58%  

Others: •  1 Post-doc (50%-1 year) •  1 Research Engineer (50%) • 

28/11/14  

Several Initiation-to-Research projects

Aymeric  Histace  -­‐  HDR   Defense  

57  

In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Theory (particular case)

gη (u) = g(u + η (x))

• 

gη : a static or memory less non-linear function

with

• 

Shaping by noise of the input-output characteristic:  

⎧1 if s ≥ k g ( s) = ⎨ ⎩0 if s  k

+∞

geff (s) = E !"g ( s + η (x, y))#$ =

η

−∞

Hard-threshold

Experiment 1

∫ g(u) f (u − s) du

Theory

fη(u): pdf of purposely injected noise (uniform)

Real

Comparison between real stochastic diffusion process and theoretical one.

28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

58  

In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Theory (particular case)

gη (u) = g(u + η (x))

• 

gη : a static or memory less non-linear function

with

• 

Shaping by noise of the input-output characteristic:  

⎧1 if s ≥ k g ( s) = ⎨ ⎩0 if s  k

+∞

geff (s) = E !"g ( s + η (x, y))#$ =

∫ g(u) f (u − s) du η

−∞

Hard-threshold

Experiment 2

Theory

Real

Comparison of the evolution of normalized cross-covariance (1000 attempts)

28/11/14  

Aymeric  Histace  -­‐  HDR   Defense  

59  

In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Result (quantification) Texture ROI

Normalized Cross Covariance wrt the iteration number of the diffusive process

Gaussian

28/11/14  

Multiplicative

Impulsive

Aymeric  Histace  -­‐  HDR   Defense  

PM S-PM

60  

In  Details:  Stochas8c  Resonance  

Useful  Noise  Effect  

Extension to Image Restoration

# I(x, y, 0) = I 0 % $ ∂I %& = div gη ( ∇I ) ∇I ∂t

(

with and

)

gη (u ) = g (u + η ( x, y )) g (u ) = e



u

2

k2

(a)  Additive zero-mean Gaussian noise with ψ0 = ψori + ξ (b)  Multiplicative Gaussian noise of mean unity with ψ0 = ψori + ξ . ψori (c)  Impulsive noise (d)  Original image

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In  Details:  Ac8ve  Contour  

Shape  Prior  

Shape Space of Legendre Moments Legendre Moments

Reconstruction p + q ≤ N0

Shape Ω

λqp

1 = Ω

∑ p ,q

λ pq Lpq ( x, y )

∫ L pq (x, y, Ω)dxdy

Ω

with

N0 = 5

N 0 = 20

N 0 = 40

⎛ x − x ⎞ ⎛ y − y ⎞ ⎟ L ⎜ ⎟ L pq (x, y, Ω ) = L p ⎜⎜ q ⎜ ⎟ 1 2 1 2 ⎜ Ω ⎟ ⎜ Ω ⎟⎟ ⎝ ⎠ ⎝ ⎠

Ln (x ) =

n ⎤ 2n + 1 1 d n ⎡ 2 x − 1 ⎥⎦ 2 2 n n! dx n ⎢⎣

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(

)

Images reconstructed from the Legendre moments for different moments’ order N0

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In  Details:  Ac8ve  Contour  

Shape  Prior  

Shape Space of Legendre Moments Greedy algorithm

How it works Starting shape

•Ω( k ) → Ωʹ′( k ) 2 2 ∂ϕ = ( I − µ Ω ) + ( I − µ Ω c ) ∇ϕ ∂t ⎛ ∇ϕ ⎞ + γ∇ ⎜⎜ ⎟⎟ ∇ϕ ⎝ ∇ϕ ⎠

)

(

Final Result

k k •Ωʹ′( ) → λ (r )

λ (rk ) = PT ( λ r − λ )

Eimage (Chan Vese)

•λ (rk ) → λ ʹ′r( k ) λ ʹ′r( k ) = λ (rk ) − β

NS

p ( λ r ) = ∑ N ( λ r ; λ r ,i , σ 2 ) i =1

∂E prior ∂λ r

k λ r = λ (r )

•λ ʹ′r( k ) → Ω( k +1)

Iterations shown in the feature space spanned by the first two principal axes

Ω( k +1) = ⎛ p + q ≤ N0 ( k ) ⎞ ⎪⎧ ⎪⎫ ʹ′ L pq x, y, Ωʹ′( k ) ⎟ > 0.5⎬ ⎨( x, y ) : ⎜ ∑ λ pq ⎪⎩ ⎪⎭ ⎝ p ,q ⎠

(

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Different from Template Matching

)

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In  Details:  Ac8ve  Contour  

Shape  Prior  

Results 2

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In  Details:  Ac8ve  Contour  

Alpha-­‐divergence  

Result 1 (Synthetic images)

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2011-­‐>2014:  The  Cyclope  Project  

2D  Detec8on   Results and Performance Bernal 88% 91%

Our Approach 99%

95%

100% 80% 60% 40% 1%

20%

5%

0% Sensibility

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Specificity

False Positive Rate

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Important  Dates  

From  2006  to  2014   09/2006

11/2008

10/2010

09/2011

11/2013

10/2014

PES

Associate Professor

SIMBAD Activity

First PhD Student

•  ETIS Lab- ICI Team •  Collaboration with F. •  Preciosio (MIDI •  Cergy-Pontoise team) •  Institute of Technology •  Beginning of the collaboration with the •  GEII Department University of Central Lancashire, UK

Cyclope Project

L. Meziou’s PhD Defense

Member of ASTRE Team

•  Embedded Image Processing for •  1 Journal Paper •  3rd PhD Student ``Histogram-Based Smart •  8 Int. Conf. (1 •  ``Smart Active Contour Videocapsule Best Student videoendoscopy Using AlphaPaper Award) for CRC early Divergence: detection’’ Application to •  1 Nat. Conf. Medical Image (GRETSI) •  Co-supervised Segmentation’’ with Olivier •  ASTRE •  1 GDR Romain •  Co-supervised with Collaboration presentation F. Precioso

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Leila Meziou

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Who  am  I?  

Research/Teaching     Computer-Aided Diagnosis 2014