論文 / 著書情報
Article / Book Information
題目(和文)
Title(English)

A Practical One-Shot Multispectral Imaging System Using a Single
Image Sensor

著者(和文)

紋野雄介

Author(English)

Yusuke Monno

出典(和文)

学位:博士（工学）,学位授与機関:東京工業大学,
報告番号:甲第9624号,
授与年月日:2014年9月25日,
学位の種別:課程博士,
審査員:田中 正行,奥富 正敏,蜂屋弘之,大山真司,小酒Citation(English)

Degree:,Conferring organization: Tokyo Institute of Technology,
Report number:甲第9624号,
Conferred date:2014/9/25,
Degree Type:Course doctor,
Examiner:,,,,

学位種別(和文)

博士論文

Category(English)

Doctoral Thesis

種別(和文)

論文要旨

Type(English)

Summary

Powered by T2R2 (Tokyo Institute Research Repository)

英範

（博士課程）Doctoral Program論 文 要 旨ＴＨＥＳＩＳ ＳＵＭＭＡＲＹ

専攻：
Department of

機械制御システム

学生氏名：

専攻

Academic Degree Requested

指導教員（主）：紋野 雄介

Student’s Name

申請学位（専攻分野）： 博士

Academic Advisor(main)

指導教員（副）：Academic Advisor(sub)Doctor of（工学田中 正行

准教授

奥富 正敏

教授

要旨（英文 800 語程度）
Thesis Summary （approx.800 English Words ）The energy of light emitted from a light source and reflected by an object
continuously spans a wide range of wavelengths. A conventional color
imaging system observes only three spectral bands, typically called RGB
bands, among the continuous wavelengths. This is because theconventional color imaging system imitates the human visual system.
However, a considerable amount of potentially available spectral
information is lost. In contrast, a multispectral imaging system with morethan three spectral bands can offer reliable spectral information that isvery useful for many computer vision and image processing applications
including digital archive, high-fidelity color reproduction, relighting,segmentation, and tracking. However, existing multispectral imaging
systems still have limitations in terms of size, cost, and real-timeprocessing.
In contrast to existing multispectral imaging systems, single-sensor
imagingwithacolor

filterarray(CFA)

anddemosaicking

iswell-established for current compact and low-cost color digital cameras.
The extension from the CFA to a multispectral filter array (MSFA) enables
us to capture a multispectral image in one shot without increase in sizeand cost. However, the extension from the CFA to the MSFA is notstraightforward and there are several challenges to do this including thedesign of the MSFA, the development of the multispectral demosaicking
algorithm, and the design of spectral sensitivity functions (SSFs) of thesensor.

）

In this dissertation, we address the above challenges and propose apractical one-shot multispectral imaging system using a single image
sensor with a MSFA. The outline of the dissertation is as follows.
Chapter 1, Introduction. In this chapter, we explain motivations of thisresearch with a brief review of existing multispectral imaging systems
and their problems.
Chapter 2, A One-Shot Multispectral Camera Prototype. In this chapter,we develop a practical one-shot multispectral camera prototype. We first
propose a novel high-performance demosaicking algorithm and a novel
five-band MSFA pattern suitable for the proposed demosaicking algorithm
at the same time. This joint design of the demosaicking algorithm and theMSFA pattern significantly improves the quality of acquired multispectral
images. Then, based on the proposed demosaicking algorithm andfive-band MSFA pattern, we develop a real one-shot multispectral camera
prototype, which can capture a five-band full-HD multispectral video at30fps. To the best of our knowledge, it is first attempt to develop ahigh-quality one-shot multispectral camera prototype in a compact digital
camera fashion.
Chapter 3, Toward a More Accurate System. In this chapter, we discuss
some improvements of the developed multispectral camera prototype
toward a more accurate system. Specifically, we discuss the following
three aspects.
(i) Further improvements of the demosaicking algorithm. Although our
proposed demosaicking algorithm in the chapter 1 can give a reasonably
high performance, there is still room for improvements. Here, we improve
the algorithm by proposing a novel residual interpolation (RI) andincorporating the RI into the demosaicking algorithm.
(ii) Study on an optimal number of spectral bands. Here, we discuss anoptimal number of spectral bands for our proposed one-shot multispectral
imaging system. We first generalize our proposed MSFA and demosaicking
algorithm to evaluate a different number of spectral bands. Then, we
experimentally investigate the optimal number of spectral bands in thescope of our proposed MSFA and demosaicking algorithm.
(iii) Optimization of SSFs. Here, we discuss optimize SSFs for theproposed MSFA and demosaicking algorithm. We first propose a simple
optimization framework to find optimal SSFs considering our proposed
MSFA and demosaicking algorithm. Then, we find the optimal SSFs interms of the estimation accuracy of the spectral reflectance.
Chapter 4, Direct Spectral Reflectance Estimation. In this chapter, we
propose a novel spectral reflectance estimation method. The acquired
multispectral image by our proposed system can be used directly ortransformed to some different domains, representatively, the spectralreflectance, the sRGB, or the Adobe RGB domain. Although this depends
on applications, one of the most important tasks in multispectral imaging
is the accurate estimation of the spectral reflectance. In contrast to atypical approach, which estimates the spectral reflectance after
demosaicking, our proposed method accurately estimates the spectralreflectance directly from raw MSFA data acquired by our proposed
one-shot multispectral imaging system.
For each chapter, we conduct experiments to demonstrate the advantagesof our proposed system over existing one-shot multispectral imaging
systems and a conventional color imaging system.
Chapter 5, Conclusion and Future Works. In this chapter, we conclude thedissertation and briefly discuss future works.
備考 : 論文要旨は、和文 2000 字と英文 300 語を 1 部ずつ提出するか、もしくは英文 800 語を 1 部提出してください。
Note : Thesis Summary should be submitted in either a copy of 2000 Japanese Characters and 300 Words (Engｌish) or 1copy of 800
Words (English).
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Attention: Thesis Summary will be published on Tokyo Tech Research Repository Website (T2R2).