#### Non-iterative exact diffuse optical tomography using simultaneous sparse representation = 동시 산재 표현을 이용한 비반복적이고 정확한 산란광 단층 촬영법

Diffuse optical tomography (DOT) is a sensitive and relatively low cost imaging modality. However, the inverse problem of reconstructing optical parameters from scattered light measurements is highly nonlinear due to the nonlinear coupling between the optical coefficients and the photon flux in the diffusion equation. Even though nonlinear iterative methods have been commonly used, such iterative processes are computationally expensive especially for the three dimensional imaging scenario with massive detector arrays such as CCD. The main contribution of this paper is a novel $\it{non-iterative}$ and $\it{exact}$ inversion algorithm when the optical inhomogeneities are $\it{sparsely}$ distributed. We show that the problem can be converted into simultaneous sparse representation problem with multiple measurement vectors (MMV) from compressed sensing framework. Fundamental $l_0$ performance bounds for the recoverable targets shows that the sparse recovery approach outperforms the conventional time-reversal MUSIC, another non-iterative method. New results on $l_1$ minimization also demonstrate that the number of recoverable targets increases as the number of source configuration grows, which coincides with theoretical prediction of $l_0$ minimization. The performance of several practical simultaneous sparse recovery algorithms such S-OMP, and $\it{p}$ -thresholding have been analyzed. Due to the ill-posedness of the DOT problem, preconditioning is found essential. The optimal preconditioning is derived, which shows that $\it{p}$ -thresholding with the optimal preconditioning is equivalent to applying thresholding after the pseudo-inverse calculation. Simulation results also confirm that our algorithms outperform the conventional time-reversal MUSIC.
Park, Hyun-Wookresearcher박현욱researcherYe, Jong-Chulresearcher예종철researcher
Publisher
한국과학기술원
Issue Date
2009
Identifier
308841/325007  / 020073403
Language
eng
Description

학위논문(석사) - 한국과학기술원 : 전기및전자공학전공, 2009.2, [ vi, 44 p. ]

Keywords

diffuse optical tomography; simultaneous sparse representation; multiple measurement vector; preconditioning; 산란광 단층 촬영법; 동시 산재 표현; 다수 측정 벡터; 사전처리; diffuse optical tomography; simultaneous sparse representation; multiple measurement vector; preconditioning; 산란광 단층 촬영법; 동시 산재 표현; 다수 측정 벡터; 사전처리

URI
http://hdl.handle.net/10203/38721
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=308841&flag=t
Appears in Collection
EE-Theses_Master(석사논문)
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