ariya presentation at june 22 2011

8/6/2019 Ariya Presentation at June 22 2011

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Facial Reconstruction from Skull

Ariya Namvong

Advisor: Dr. Rungrote Nilthong

June 22, 2011. Mae Fah Luang University



Overview

Introduction

Facial reconstruction concept

Face dissection

Skull Registration

Face comparing

Reference candidate selection for each part

Example of reconstruction

Conclusion

Discussion

Here comes your footer



Facial Reconstruction Concept

Reconstruct face from unknown skull

Dissect skull / face into 4 sections

- orbital / eyes

- nasal / nose- dental / mouth

- remaining part

Search for best candidate for each

section from reference head.

Deform craniometric landmarks from

reference skull into unknown skull

Combine all section together to

produce final result




Face Dissection




Skull Registration using Iterative Closest Point (ICP)

All skull have to be registered (align data to the same position and

orientation) before further process.

Minimize the distance between the pair of closest point (one from target

point cloud another one from reference point cloud) by iterative translation

and rotation

Translation: up, down, left, right, front and back

Rotation: pitch, roll and yaw




Iterative Closest Point - ICP


Before Registration

Red is point cloud to be registered to green.



Iterative Closest Point - ICP


After registration

Red is point cloud to be registered to green.



Face Comparison ± surface of absolute error


This comparison based on skull registration. If register face beforecomparing, the result may be different. (unit in mm.)



Reference candidate selection for each part

In this experiment, face is dissected to 4 parts: eyes, nose, mouth and

remaining

Each part will be selected as reference part considering from skull feature.

- Orbital curve for eyes

- Nasal curve for nose

- Dental surface for mouth

- Remaining point cloud for remaining part




Orbital Curve


The best match for orbital curve will be selected as candidate for eyessection.



Nasal Curve


The best match for Nasal curve will be selected as candidate for nosesection.



Dental Surface


The best match for dental surface will be selected as candidatefor mouth section.



Remaining Part


The best match for point cloud of this part will be selected as candidate for remaining section.



Example: reconstruction of Head 5


Distance table

Similarity table(considered from distance

table, less distance is more

similarity)



Result from Rank 1


Integrate 4 sections from the best match (rank 1)

Target face Rank 1 reconstructed face Error surface



Result from Rank 2


Integrate 4 sections from the second best match (rank 2)




Result from Rank 3


Integrate 4 sections from the rank 3




Result from Rank 1 & 2


Integrate 4 sections from the rank 1 and rank 2

Target face Rank 1 and 2 reconstructed face Error surface

Reconstruction face from only rank 1 produces too much reference bias, lead to the idea of reconstruction

from more than one reference.



Result from Rank 1, 2 & 3


Integrate 4 sections from the rank 1 and rank 2

Target face Rank 1,2 and 3 reconstructed face Error surface

Reconstruction face from only rank 1 produces too much reference bias, lead to the idea of reconstruction

from more than one reference.





Integrate 4 sections from the rank 1, rank 2 and rank 3





This result very different from target face


Integrate 4 sections from the rank 1, rank 2 and rank 3


Nose width incorrect, mouth width incorrect and face shape very different while skull shape not much different



Conclusions

The best candidate selection method have to be further research

Absolute error surface is just a guideline for evaluation.

There are no evaluation method better than human visual evaluation.

Face shape, nose shape and mouth shape are play important role for

human face recognition. The next research plan have to focus on these.

Some of facial feature does not indicate directly from skull

(have to more further study)

The manual sculpturing knowledge will be added to future research.

(for example: mouth width can be determined from «, nose width can bedetermined from «)

Cephalometric landmarks (facial landmarks) may be added in the future.




Relation of facial feature and skull


Wilkinson, C. (2004), Forensic Facial Reconstruction, Cambridge University Press.



Discussion


ariya presentation at june 22 2011

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