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Investigation of Alternative Contactless Optical Surface Reconstruction Methods

Rostedt, Eric LU and Bolin, Rickard (2021) In Master’s Theses in Mathematical Sciences FMSM01 20211
Mathematical Statistics
Abstract
Object and surface reconstruction in 3D is commonly used in production tolerance validation. Depending on the required level of accuracy, a multitude of different methods are available, each with their own advantages and disadvantages.

This thesis aims to investigate alternative surface reconstruction methods which utilise that all possible light paths are known along a given one-dimensional curve on the surface of a material with known refractive index. This makes it possible to calculate the expected light intensity for the curve. By comparing the expected intensity to a reference intensity from when there is no surface to reflect off, it is possible to deduce information about the surface.

Several methods utilising this... (More)
Object and surface reconstruction in 3D is commonly used in production tolerance validation. Depending on the required level of accuracy, a multitude of different methods are available, each with their own advantages and disadvantages.

This thesis aims to investigate alternative surface reconstruction methods which utilise that all possible light paths are known along a given one-dimensional curve on the surface of a material with known refractive index. This makes it possible to calculate the expected light intensity for the curve. By comparing the expected intensity to a reference intensity from when there is no surface to reflect off, it is possible to deduce information about the surface.

Several methods utilising this information to reconstruct the surface of an object are investigated and evaluated. The types of investigated methods range from one-dimensional iterative methods to Convolutional Neural Network based Encoder-Decoder architectures.

The evaluation shows that it is possible to deduce information about the general shape of the surface, but that the non-linear nature of the problem makes it difficult to identify any fine details. The methods showing the most promising results use a combination of principal components and simple geometric relationships in the data to reconstruct the surface. (Less)
Please use this url to cite or link to this publication:
author
Rostedt, Eric LU and Bolin, Rickard
supervisor
organization
course
FMSM01 20211
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Geometric transformation, Principal Component Analysis, Helmholtz equation, CNN based Encoder-Decoder
publication/series
Master’s Theses in Mathematical Sciences
report number
LUTFMS-3407-2021
ISSN
1404-6342
other publication id
2021:E7
language
English
id
9044014
date added to LUP
2021-06-10 08:04:09
date last changed
2021-06-10 08:04:09
@misc{9044014,
  abstract     = {{Object and surface reconstruction in 3D is commonly used in production tolerance validation. Depending on the required level of accuracy, a multitude of different methods are available, each with their own advantages and disadvantages. 

This thesis aims to investigate alternative surface reconstruction methods which utilise that all possible light paths are known along a given one-dimensional curve on the surface of a material with known refractive index. This makes it possible to calculate the expected light intensity for the curve. By comparing the expected intensity to a reference intensity from when there is no surface to reflect off, it is possible to deduce information about the surface.

Several methods utilising this information to reconstruct the surface of an object are investigated and evaluated. The types of investigated methods range from one-dimensional iterative methods to Convolutional Neural Network based Encoder-Decoder architectures. 

The evaluation shows that it is possible to deduce information about the general shape of the surface, but that the non-linear nature of the problem makes it difficult to identify any fine details. The methods showing the most promising results use a combination of principal components and simple geometric relationships in the data to reconstruct the surface.}},
  author       = {{Rostedt, Eric and Bolin, Rickard}},
  issn         = {{1404-6342}},
  language     = {{eng}},
  note         = {{Student Paper}},
  series       = {{Master’s Theses in Mathematical Sciences}},
  title        = {{Investigation of Alternative Contactless Optical Surface Reconstruction Methods}},
  year         = {{2021}},
}