Defending thesis (english)

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You can see the slides of my defending thesis, title: "3-D Visual Reconstruction: A System Perspective"

Transcript of Defending thesis (english)

3-D VISUAL RECONSTRUCTION : ASYSTEM PERSPECTIVE

Student:

Guillermo Enrique Medina Zegarra

Advisor:PhD. Edgar Lobaton, USA

Co-AdvisorPhD. Nestor Calvo, Argentina

Arequipa, Peru

May 07, 2012

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Index

Index

1 Introduction

2 Image formation

3 Geometry from two views

4 Proposal

5 Results

6 Limitations and problems founded

7 Conclusions and future work

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Index

1 IntroductionMotivation and contextDefinition the problemGeneral objectiveSpecific objectives

2 Image formation

3 Geometry from two views

4 Proposal

5 Results

6 Limitations and problems founded

7 Conclusions and future work

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Motivation and context

Limitations on pre-Renaissance to create 3D.

The artists during the Renaissance and the depth.

The vanishing points and three dimensions.

(a) Jesus intoJerusalem

(b) The School of Athens

Figura: Painting pre-Renaissance and Renaissance [Ma et al., 2004].

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Motivation and context

Limitations on pre-Renaissance to create 3D.

The artists during the Renaissance and the depth.

The vanishing points and three dimensions.

(a) Jesus intoJerusalem

(b) The School of Athens

Figura: Painting pre-Renaissance and Renaissance [Ma et al., 2004].

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Motivation and context

Limitations on pre-Renaissance to create 3D.

The artists during the Renaissance and the depth.

The vanishing points and three dimensions.

(a) Jesus intoJerusalem

(b) The School of Athens

Figura: Painting pre-Renaissance and Renaissance [Ma et al., 2004].

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Definition the problem

Physical architecture, location, distribution and lighting.

(a) One camara[Cipolla et al., 2010]

(b) Artificial lighting[VISGRAF., 2012]

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Definition the problem (cont...)

Figura: How to get the parameters to map an object to the image plane? [Faugeras, 1993].

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Definition the problem (cont...)

Figura: How to find corresponding points ? [Szeliski, 2011].

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Definition the problem (cont...)

Figura: How to find a 3D point of each pair of corresponding points ?[Szeliski, 2011].

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Definition the problem (cont...)

Figura: How to reconstruction and smooth a surface from a cloud ofpoints ? [Hartley and Zisserman, 2004].

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General objective

Objetivo general

Propose a model for the reconstruction of a 3D image of an objectfrom two images captured by two cameras located adequately.

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Specific objectives

Specific objectives

Position two digital cameras on a physical architecture for imageacquisition and calibration.

Rectification of the stereo image pair and calculate the disparitymap through the normalized cross-correlation.

Create the object’s surface from the Delaunay triangulation of thedisparity map.

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Index

1 Introduction

2 Image formation

3 Geometry from two views

4 Proposal

5 Results

6 Limitations and problems founded

7 Conclusions and future work

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Pinhole camera model

Help to understand the image formation from geometric point ofview.

Parts of the pinhole camera model: optical center (o), focaldistance (f ) and image plane (I ).

x = op ∩ I x ∈ R2 , p ∈ R3

Figura: Pinhole camera model [Ma et al., 2004].

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Pinhole camera model (cont...)

Figura: Example of the projection of an object on image plane .

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Index

1 Introduction

2 Image formation

3 Geometry from two views

4 Proposal

5 Results

6 Limitations and problems founded

7 Conclusions and future work

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Epipolar geometry

Study the geometric relationship and mathematical analysis of a3-D p point in their image planes.

Figura: Two projections x1, x2 ∈ R2 of a 3-D point p from two vantagepoints [Ma et al., 2004].

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Epipolar geometry (cont...)

Figura: Example of the projection of a cube image on two image planes.

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Rectification

Figura: Rectification of the stereo image pair [Fusiello et al., 2000].

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Disparity calculation

(a) (b) Disparity map

(a - b) Tsukuba image pair [Scharstein and Szeliski, 2002].

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Index

1 Introduction

2 Image formation

3 Geometry from two views

4 Proposal

5 Results

6 Limitations and problems founded

7 Conclusions and future work

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Pipeline of the proposal

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Description of the proposed pipeline

Physical architecture

Image acquisition

Calibration

Canon SD1200 Sony DSC-S750

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Description of the proposed pipeline

Physical architecture

Image acquisition

Calibration

features Sony DSC-S750 Canon SD1200 ISSensor type CCD CCDImage size 640 × 480 640 × 480ISO 100 100Flash off off

Technical characteristics of the two digital cameras

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Description of the proposed pipeline

Physical architecture

Image acquisition

Calibration

Chessboard (7 × 10)

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Description of the proposed pipeline

Rectification

Linear search

The correspondence of points isin the same horizontal line

Original images Rectified images

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Description of the proposed pipeline

Pre-processing

Manual segmentation

Gaussian filter

Rectified images Pre-processed images

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Description of the proposed pipeline

Disparity map

Normalized Cross-Correlation

Median filter

Left image pre-processed Right image pre-processed Disparity map

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Description of the proposed pipeline

3-D mesh

Delaunay triangulation

Intersection of lines

3-D mesh

Disparity map Point Cloud 3-D mesh

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Description of the proposed pipeline

Reconstructed model

Smoothing the surface

Texturing of the right image

Creation of the surface Smoothing of the surface Texturing of the model

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“Cubo magico”

Original images Rectified images Pre-processed images

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“Cubo magico” (cont...)

Disparity map Point Cloud 3-D mesh

Creation of the surface Smoothing of the surface Texturing of the model

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Multiple views of the “Magic Cube”

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Multiple views of the “Magic Cube”

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Multiple views of the “Magic Cube”

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Multiple views of the “Magic Cube”

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Multiple views of the “Magic Cube”

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Multiple views of the “Magic Cube”

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Multiple views of the “Magic Cube”

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Multiple views of the “Magic Cube”

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Index

1 Introduction

2 Image formation

3 Geometry from two views

4 Proposal

5 ResultsTeddy bearHuman face

6 Limitations and problems founded

7 Conclusions and future work

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Teddy bear

Original images Rectified imagenes Pre-processed imagenes

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Teddy bear (cont...)

Disparity map Cloud of points 3-D mesh

Creation of the surface Smoothing of the surface Texturing of the model

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Human face

Original images Rectified imagenes Pre-processed imagenes

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Human face (cont...)

Cloud of points Model without smoothing Smoothing model “Transformed” model

3-D mesh Model without smoothing Smoothing model “Transformed” model

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Index

1 Introduction

2 Image formation

3 Geometry from two views

4 Proposal

5 Results

6 Limitations and problems founded

7 Conclusions and future work

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Limitations and problems founded

neighbourhood size Imperfections of the created model

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Limitations and problems founded (cont...)

Imperfect original image Imperfect original image

Wrong disparity map “Amorphous” 3-D reconstruction

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Index

1 Introduction

2 Image formation

3 Geometry from two views

4 Proposal

5 Results

6 Limitations and problems founded

7 Conclusions and future work

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Conclusions

Physic architecture was designed simple and profit.

Lighting conditions must be adequate.

A pipeline was proposed with a sequence of steps needed to get a3-D reconstruction of a stereo image pair.

The method for the disparity calculation is simple and no robust.

There is a strong dependency between each step of thereconstruction.

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Future work

Create an environment withappropriate conditions for calibration,lighting and image acquisition.

Physical architecture and artificial lighting [Bradley et al., 2008]

Use multiple cameras.

Multiple views [Hartley and Zisserman, 2004]

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Future work

Create an environment withappropriate conditions for calibration,lighting and image acquisition.

Physical architecture and artificial lighting [Bradley et al., 2008]

Use multiple cameras.

Multiple views [Hartley and Zisserman, 2004]

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Future work (cont...)

Use robust methods.

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Publicated on

Symposium article“3-D visual reconstruction : a system perspective.”G. Medina-Zegarra y E. Lobaton2nd International Symposium on Innovation andTechnology (2011)pag. 102-107, November 28-30, Lima, PeruISBN: 978-612-45917-1-6Place: Technological University of Peru

Editor: International Institute of Innovation andTechnology (IIITEC)Chair: Mario Chauca Saavedra

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Acknowledgements

X PhD. Alex CuadrosX PhD. Alfedro MirandaX Mag. Alfedro PazX PhD. Carlos LeytonX PhD(c). Christian Lopez del AlamoX PhD. Eduardo TejadaX PhD. Jesus MenaX PhD. Jose Corrales-NievesX PhD(c). Juan Carlos GutierrezX Lic. Luıs ParejaX Family Barrios Neyra

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References

Bradley, D., Popa, T., Sheffer, A., Heidrich, W., and Boubekeur, T. (2008).

Markerless garment capture.ACM Transactions on Graphics (TOG), 27:99:1–99:9.

Cipolla, R., Battiato, S., and Farinella, G. M. (2010).

Computer Vision: Detection, Recognition and Reconstruction.Springer.

Faugeras, O. (1993).

Three-dimensional Computer Vision: A Geometric Viewpoint.The MIT Press. ISBN: 0262061589.

Fusiello, A., Trucco, E., and Verri, A. (2000).

A compact algorithm for rectification of stereo pairs.Machine Vision and Applications, 12:16–22.

Hartley, R. and Zisserman, A. (2004).

Multiple View Geometry in Computer Vision. Second Edition.Cambridge University Press. ISBN: 0521540518.

Ma, Y., Soatto, S., Kosecka, J., and Sastry, S. S. (2004).

An Invitation to 3D Vision from Images to Geometric Models.Springer. ISBN: 0387008934.

Scharstein, D. and Szeliski, R. (2002).

A taxonomy and evaluation of dense two-frame stereo correspondence algorithms.International Journal of Computer Vision, 47:7–42.

Szeliski, R. (2011).

Computer Vision: Algorithms and Applications.Springer. ISBN: 9781848829343.

VISGRAF. (2012).

Vision and graphics laboratory.Institute of Pure and Applied Mathematics (IMPA) http: // w3. impa. br/ ~ anafucs/ 3d_ museum/ 14Enero.

3-D VISUAL RECONSTRUCTION : ASYSTEM PERSPECTIVE

Student:

Guillermo Enrique Medina Zegarra

Advisor:PhD. Edgar Lobaton, USA

Co-AdvisorPhD. Nestor Calvo, Argentina

Arequipa, Peru

May 07, 2012

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View points (perception)

(a) The glass is half fullor half empty ?

(b) is it a duck or a rabbit ?