岡部 孝弘(Takahiro OKABE)

大学院情報工学研究院 知能情報工学研究系

住所: 〒820-8502 福岡県飯塚市川津680-4
オフィス: 研究棟E714
電話: 0948-29-7629


D2 北原 雅啓     M2 大矢 慎之介     M1* 王 超     B4 大屋 瑠璃
小田 武蔵     M1 相島 初花 鎌田 春
小屋松 孝治 黒木 武 田中 奈津美
鳥居 杜朗 中島 拓人
中嶋 倫太郎 日高 大地


[2017年度] [過去の担当]




    Light Transport:
We propose a method for acquiring the multispectral LT (Light Transport) by using a single off-the-shelf multi-primary DLP projector; it does not require any self-built equipment, geometric registration, and temporal synchronization. Specifically, based on the rapid color switch due to a rotating color wheel in the projector, we present a method for estimating the spectral properties of the projector in a non-destructive manner, and a method for acquiring the images of a scene illuminated only by one of the primary colors.

    Diffuse-Specular Separation:
We propose a robust method for separating reflection components in a set of images of an object taken under multispectral and multidirectional light sources. We consider the set of images as the 3D data whose axes are the pixel, the light source color, and the light source direction, and then show the inherent structures of the 3D data. Based on those structures, our proposed method separates diffuse and specular reflection components by combining sparse NMF and SVD with missing data. We show that our method works better than some of the state-of-the-art techniques.

    Light Field Acquisition:
We propose an approach to measuring the 4D light field of a self-luminous extended light source by using an LC panel, i.e. a programmable filter and a diffuse-reflection board. Our proposed approach recovers the 4D light field from the images of the board illuminated by the light radiated from an extended light source and passing through the LC panel. We make use of the feature that the transmittance of the LC panel can be controlled both spatially and temporally, and recover 4D light fields efficiently and densely on the basis of multiplexed sensing and adaptive sensing.

    Image-Based Lighting:
We acquire the omnidirectional lighting environment of a real scene by using a hyperspectral camera, which has several tens of bands in visible spectrum, and then use the acquired spectral lighting environment for image synthesis. In particular, we compare the images synthesized by using the spectral lighting environment with those using the RGB lighting environment, and evaluate the difference between them. We demonstrate that the spectral lighting environment is highly important for rendering fluorescent materials.

We propose a MAP-based multiframe super-resolution method for flickering objects such as LED electronic message boards. Since they often flicker at low refresh rates, missing areas where LEDs are off during the exposure time of a camera by chance are observed. To suppress unexpected artifacts due to those missing areas, our proposed method detects outlier pixels on the basis of the spatio-temporal analysis of pixel values, and removes them from the MAP estimation by incorporating the weights of pixels into the likelihood term.

    Inverse Lighting:
We extend inverse lighting by taking an unknown and nonlinear radiometric response function of a camera into consideration, and propose a method for simultaneously recovering the lighting environment of a scene and the response function from a single image of an object. Through a number of experiments, we demonstrate that the performance of our proposed method depends on the lighting distribution, response function, and surface albedo, and address the conditions under which the simultaneous recovery works well.

    Shape and Reflectance Recovery:
We propose a method for simultaneously estimating the spectral reflectance and normal per pixel from a small number of images taken under multispectral and multidirectional light sources by integrating multispectral imaging and photometric stereo. In addition, taking attached shadows observed on curved surfaces into consideration, we derive the minimum number of images required for the simultaneous estimation and propose a method for selecting the optimal light sources in terms of noise.



2017年03月 -九州工業大学 大学院情報工学研究院 知能情報工学研究系 教授
2013年04月 - 2017年02月 九州工業大学 大学院情報工学研究院 知能情報工学研究系 准教授
2012年11月 - 2013年03月 東京大学 生産技術研究所(佐藤研究室) 特任准教授
2007年04月 - 2012年10月 東京大学 生産技術研究所(佐藤研究室) 助教
2007年01月 - 2007年03月 東京大学 生産技術研究所(佐藤研究室) 助手
2001年01月 - 2006年12月 東京大学 生産技術研究所(佐藤研究室) 技官・技術職員
2000年12月東京大学大学院 理学系研究科 物理学専攻(宇宙理論研究室) 博士課程中途退学
1999年03月東京大学大学院 理学系研究科 物理学専攻(宇宙理論研究室) 修士課程修了
1997年03月東京大学 理学部 物理学科 卒業
1993年03月愛媛県立西条高等学校 理数科 卒業
2017年04月 - 国立情報学研究所 客員教授
2013年04月 - 東京大学 生産技術研究所 協力研究員
2014年04月 - 2017年03月国立情報学研究所 客員准教授
2011年10月 - 2012年09月 テュービンゲン大学(コンピュータグラフィックス研究室:ヘンドリック・レンシュ教授) 客員研究員
2011年09月ウルム大学(コンピュータグラフィックス研究室:ヘンドリック・レンシュ教授) 客員研究員
2011年03月東京大学 博士(情報理工学)


[論文誌・会議等] [指導学生の受賞] [その他]


[論文誌] [会議等] [その他]


[科研費: 代表者] [民間]

最終更新日: 2017年8月22日