Language：English   Publisher：Institute of Industrial Applications engineers (IIAE)  

We propose an iterative raster scan algorithm for superpixel segmentation, which is based on the K-means clustering algorithm. The proposed algorithm updates the class label of each pixel only at the boundaries of superpixels in a raster scan order, and refers to only two neighboring pixels per pixel for updating the variables. Therefore, the proposed algorithm is computationally efficient compared with existing methods. Experimental results show that the proposed algorithm generates compact and adherent superpixels in a finite number of iterations of the raster scan process.

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ICIC Express Letters  

The purpose of this study is to introduce a novel prior, and demonstrate its effectiveness in underwater image enhancement. In this paper, we propose a prior that the minimum and maximum values of each of RGB color channels in a scene under a white light source are almost the same as the minimum and maximum values of possible pixel values, and call it color channel prior (CCP). We also combine the proposed CCP with gray world assumption (GWA), and use it for color correction of underwater images. Experimental results demonstrate that the proposed method can enhance the contrast of underwater images by using CCP, and reduce bluish color deviation by using GWA.

DOI： 10.24507/icicel.17.08.849

Scopus

Language：English   Publisher：Institute of Industrial Applications engineers( IIAE )  

We propose a visual cryptography method based on error diffusion for generating share images of the same size as a given secret image. Two share images printed on separate transparencies are stacked to decrypt a secret image, where opaque and transparent pixels correspond to black (0) and white (1), respectively. An opaque pixel on the stacked image can be given by three combinations of pixel values in two share images: `00', `01' and `10'. This arbitrariness in opaque pixels in a secret image is effectively used in the proposed method. Experimental results show that the proposed method conceals a secret image in share images acceptably, and the quality of the reconstructed secret image given by stacking transparencies onto which the share images by the proposed method are printed is better than that of the conventional methods in terms of visual comparison and quantitative evaluation with the peak signal-to-noise ratio (PSNR).

CiNii Research

Language：English   Publisher：MDPI (Multidisciplinary Digital Publishing Institute)  

Mathematical morphology is a fundamental tool based on order statistics for image processing, such as noise reduction, image enhancement and feature extraction, and is well-established for binary and grayscale images, whose pixels can be sorted by their pixel values, i.e., each pixel has a single number. On the other hand, each pixel in a color image has three numbers corresponding to three color channels, e.g., red (R), green (G) and blue (B) channels in an RGB color image. Therefore, it is difficult to sort color pixels uniquely. In this paper, we propose a method for unifying the orders of pixels sorted in each color channel separately, where we consider that a pixel exists in a three-dimensional space called order space, and derive a single order by a monotonically nondecreasing function defined on the order space. We also fuzzify the proposed order space-based morphological operations, and demonstrate the effectiveness of the proposed method by comparing with a state-of-the-art method based on hypergraph theory. The proposed method treats three orders of pixels sorted in respective color channels equally. Therefore, the proposed method is consistent with the conventional morphological operations for binary and grayscale images.

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/jimaging8090247

Language：English   Publisher：Journal of Imaging  

Mathematical morphology is a fundamental tool based on order statistics for image processing, such as noise reduction, image enhancement and feature extraction, and is well-established for binary and grayscale images, whose pixels can be sorted by their pixel values, i.e., each pixel has a single number. On the other hand, each pixel in a color image has three numbers corresponding to three color channels, e.g., red (R), green (G) and blue (B) channels in an RGB color image. Therefore, it is difficult to sort color pixels uniquely. In this paper, we propose a method for unifying the orders of pixels sorted in each color channel separately, where we consider that a pixel exists in a three-dimensional space called order space, and derive a single order by a monotonically nondecreasing function defined on the order space. We also fuzzify the proposed order space-based morphological operations, and demonstrate the effectiveness of the proposed method by comparing with a state-of-the-art method based on hypergraph theory. The proposed method treats three orders of pixels sorted in respective color channels equally. Therefore, the proposed method is consistent with the conventional morphological operations for binary and grayscale images.

DOI： 10.3390/jimaging9070139

Scopus

PubMed

Language：Japanese   Publisher：電子情報通信学会  

ハーフトーニングの歴史は古いが、現代でも新たな方法が研究、開発されている。本稿では、ハーフトー ニングの過程をボックスフィルタリングの逆問題として定式化し、その近似解としてハーフトーン画像を求める反復解法を提案する。提案手法により、迷路のようなパターンをもつハーフトーン画像が得られることを実例で示す。

CiNii Research

Publisher：Proceedings of SPIE - The International Society for Optical Engineering  

For effective super-resolution processing of video images, video images should not be processed as frame-by-frame two-dimensional information, but as spatio-temporal information, including information in the time axis direction. Most of the proposed video super-resolution processing based on deep learning uses 2D convolutional neural networks (CNNs). Therefore, the system is based on the 2D CNNs with the additional processing related to change from frame to frame. Instead of processing video images separately in space and time, comprehensive processing as spatio-temporal information can be expected to be more flexible and effective. In this research, we propose a video super-resolution process that processes spatio-temporal information by 3D-CNNs and GAN (Generative adversarial networks). By using 3D-CNNs, the configuration does not require motion alignment as preprocessing. Since the essential purpose of the super-resolution process is to predict missing high-frequency components, we added a process that directly predicts the difference between the high-resolution image and the corresponding bicubic interpolated low-resolution image.

DOI： 10.1117/12.2666980

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ICIC Express Letters  

We propose a method for generating variable-size pixel art from a given image. The variable-size pixel art is a relaxed version of conventional pixel art composed of regular square patterns. By performing row/column clustering, we generate rectangles of various sizes on an image. Then, applying a post processing with an emboss filter, we add a relief effect to the generated rectangle pattern. Experimental results show an artistic effect generated by the proposed method which imitates an impression of a contemporary pixel art.

DOI： 10.24507/icicel.16.09.965

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/jimaging8090247

Language：Japanese   Publisher：電子情報通信学会  

カラー画像に含まれる色をパステルカラーに変更する方法を提案する。限定色画像の生成では、各色に近い色をカラーパレットから選択する方法が基本的であるが、カラー画像とカラーパレットの色分布が大きく異なると、同系色の色ばかりが選ばれてコントラストが低下する場合がある。そこで本論文では、色の選択を輸送問題として定式化し、１つの色を使用できる頻度に制限を設けることによって多様な色を選択する方法を提案し、実際の画像をパステルカラー化した実験例を示す。

CiNii Research

Language：English   Publisher：Institute of Industrial Applications Engineers  

We propose a method for detecting a facial symmetry axis from a frontal face image. The proposed method adopts a voting procedure like Hough transform that transforms a set of edge points into perpendicular bisectors of two different edge points selected from the set. The initial guess of a symmetry axis is adjusted accurately by the following fine tuning procedure. Experimental results show that the proposed method correctly detects facial symmetry axes from real face images visually and quantitatively.

DOI： 10.12792/jiiae.10.53

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Language：English  

researchmap

Language：Japanese   Publisher：電子情報通信学会  

D-11-30

CiNii Research

Language：English   Publisher：IIAE  

Golden ratio is considered as an index of beauty in both natural and artificial objects. In this paper, we propose a method for generating face images based on the golden ratios discovered so far for facial beauty. For example, we focus on some existing golden ratios for facial beauty, where we solve underdetermined systems by introducing additional and reasonable equations. Experimental results showed that the proposed method generates natural face images based on user inputs. We also evaluated the beauty of the generated face images objectively and subjectively, and observed that the proposed method improved the evaluation scores on average for both objective and subjective evaluations.

DOI： 10.12792/jiiae.10.11

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Language：English  

researchmap

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DOI： 10.1587/nolta.11.446

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.3169/itej.74.597

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/jimaging6040023

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.12792/jiiae.8.56

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DOI： 10.1587/transfun.E102.A.486

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

This study proposes a method to improve the saturation of colors during hue-preserving color image enhancement without the gamut problem. First, the color of each pixel in an input image is projected onto one of three bisecting planes or bisectors of an RGB color cube to increase saturation. Then, that projected color is transformed into a target color with a designated luminance and the same hue as the original color. Experimental results show that the proposed method can enhance color images better than can recent hue-preserving color image enhancement methods.

DOI： 10.1016/j.icte.2017.07.003

Language：Japanese   Publishing type：Research paper (scientific journal)  

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DOI： 10.3169/itej.72.J105

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3169/itej.72.J86

Language：English   Publishing type：Research paper (scientific journal)  

Given a filtering operation for images, we consider a problem for inverting it. If the algorithm of the original,i.e. forward filter is explicitly expressed, its inversion is tractable. However, if its algorithm is unknown exactly, it is hard to be reversed. We present, in this paper, a simple solution for this problem only by iterating the forward filter. This method can be used for a wide class of image filters including ones built in photo-retouch softwares. Examples are shown for smoothing, sharpening, halftoning and resizing filters.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.3169/itej.71.J214

Language：English   Publishing type：Research paper (scientific journal)  

A large number of color image enhancementmethods are based on themethods for grayscale image enhancement in which the main interest is contrast enhancement. However, since colors usually have three attributes, including hue, saturation and intensity of more than only one attribute of grayscale values, the naive application of themethods for grayscale images to color images often results in unsatisfactory consequences. Conventional hue-preserving color image enhancement methods utilize histogram equalization (HE) for enhancing the contrast. However, they cannot always enhance the saturation simultaneously. In this paper, we propose a histogram specification (HS) method for enhancing the saturation in hue-preserving color image enhancement. The proposed method computes the target histogram for HS on the basis of the geometry of RGB (rad, green and blue) color space, whose shape is a cube with a unit side length. Therefore, the proposed method includes no parameters to be set by users. Experimental results show that the proposed method achieves higher color saturation than recent parameter-free methods for hue-preserving color image enhancement. As a result, the proposed method can be used for an alternative method of HE in hue-preserving color image enhancement.

DOI： 10.3390/jimaging3030024

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/jimaging3030024

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DOI： 10.3169/itej.71.J155

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DOI： 10.25046/aj0203121

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

In this paper, we propose a method for color error diffusion based on the Neugebauer model for color halftone printing. The Neugebauer model expresses an arbitrary color as a trilinear interpolation of basic colors. The proposed method quantizes the color of each pixel to a basic color which minimizes an accumulated quantization error, and the quantization error is diffused to the ratios of basic colors in subsequent pixels. Experimental results show that the proposed method outperforms conventional color error diffusion methods including separable method in terms of eye model-based mean squared error.

DOI： 10.1587/transfun.E99.A.1758

Language：Japanese   Publishing type：Research paper (scientific journal)  

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DOI： 10.3169/itej.70.J185

Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

Recently, hue-preserving color image enhancement methods have been proposed by several researchers. However, the theoretical comparison of the performance of their methods has not been conducted yet. In this paper, we propose a hue-preserving saturation maximization method, and show a relationship of the saturation of enhanced colors by related methods. We also demonstrate the correctness of the relationship experimentally.

DOI： 10.1587/transfun.E98.A.927

Language：English   Publishing type：Research paper (scientific journal)  

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DOI： 10.1109/LSP.2014.2314647

Language：Japanese   Publishing type：Research paper (scientific journal)  

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DOI： 10.3169/itej.68.J108

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Size-Adaptive Hepatocellular Carcinoma Detection from 3-D CT Images Based on the Level Set Method

Language：English   Publishing type：Research paper (scientific journal)  

Conventional centroidal Voronoi tessellation (CVT) in an image plane divides the plane into several Voronoi regions. Generally, the boundaries of Voronoi regions do not coincide with the edges of the image. Therefore, image segmentation based on CVT often disturbs the edges. We developed an edge-preserving CVT technique that reduces the disturbance around the edges of an image and the Voronoi boundaries and applied it to non-photorealistic halftoning.

DOI： 10.3169/itej.67.J410

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

We propose a method for generating halftone images from grayscale images based on their integral images. The pixel values of a halftone image are determined so that the errors between the integral image of the halftone image and that of the grayscale image are minimized.

DOI： 10.3169/itej.67.J303

Language：English   Publishing type：Research paper (scientific journal)  

We propose a method for enhancing the contrast of grayscale images by equalizing their weighted histograms on the basis of the gradient norm, and we quantitatively evaluate the effectiveness of the proposed method.

DOI： 10.3169/itej.67.J296

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LSP.2013.2265274

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

We propose an image resizing method using row/column removal and addition based on the clustering of rows and columns in an image. To shrink an image, we first separately cluster a set of rows and a set of columns in the original image and then replace each cluster with a representative row or column to reduce the numbers of rows and columns. To enlarge an image, we add linearly interpolated rows and columns between adjacent clusters. Experimental results show that the proposed method can shrink or enlarge given images while preserving the aspect ratios of the main objects in the images.

DOI： 10.3169/itej.67.J45

Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

We propose edge-preserving smoothing (EPS) filters based on minimum spanning trees (MSTs) on image planes. The shape of the filter window is adaptively determined for each pixel by the MST, which avoids stepping over edges in images. Experimental results showed that the proposed MST filters can remove impulse noise better than conventional EPS filters.

DOI： 10.3169/itej.66.J287

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

We propose a method for enhancing the contrast of color images by transforming the original colors into the colors on the boundary of RGB color space. Experimental results show that the proposed method generates colorful and contrast-enhanced images.

DOI： 10.3169/itej.66.J227

Language：English   Publishing type：Research paper (scientific journal)  

We address the problem of permutation ambiguity in blind separation of multiple mixtures of multiple images (resulting, for instance, from multiple reflections through a thick grass plate or through two overlapping glass plates) with unknown mixing coefficients. In this paper, first we devise a generalized multiple correlation measure between one gray image and a set of multiple gray images and derive a decorrelation-based blind image separation algorithm. However, many blind image separation methods, including this algorithm, suffer from a permutation ambiguity problem that the success of the separation depends upon the selection of permutations corresponding to the orders of the update operations. To solve the problem, we improve the first algorithm above by decorrelating the mixtures while searching for the appropriate update permutation using a pruning technique. We show its effectiveness through experiments with artificially mixed images and real images.

DOI： 10.1016/j.patrec.2011.11.011

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

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We have proposed a method for clipping a rectangular region from an image by minimizing a weighted intersection of two color histograms that are constructed with pixels inside and outside the rectangular region. We propose a method for detecting salient regions which is based on two color histograms obtained by the clipping. We experimentally compared our method with the latest method by Achanta et al., and the results show that salient regions can be detected more clearly with our method.

DOI： 10.3169/itej.65.996

Language：English   Publishing type：Research paper (scientific journal)  

We describe a method for reducing an image by seam carving using a color saliency map in which higher values are assigned to the pixels with the object's colors. Our experimental results show that the proposed method can preserve the salient regions in the reduced images better than the conventional methods.

DOI： 10.3169/itej.65.1003

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)  

Linear discriminant analysis (LDA) is one of the wellknown schemes for feature extraction and dimensionality reduction of labeled data. Recently, two-dimensional LDA (2DLDA) for matrices such as images has been reformulated into symmetric 2DLDA (S2DLDA), which is solved by an iterative algorithm. In this paper, we propose a non-iterative S2DLDA and experimentally show that the proposed method achieves comparable classification accuracy with the conventional S2DLDA, while the proposed method is computationally more efficient than the conventional S2DLDA.

DOI： 10.1587/transinf.E94.D.926

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

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Real-Time Nonlinear FEM-Based Simulator for Deforming Volume Model of Soft Organ by Neural Network

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

One of the necessary techniques for constructing a virtual museum is to estimate the surface normal and the albedo of the artwork which has high specularity. In this paper, we propose a novel photometric stereo method which is robust to the specular reflection of the object surface. Our method can also digitize the artwork arranged inside a glass or acrylic display case without bringing the artwork out of the display case. Our method treats the specular reflection at the object surface or at the display case as an outlier, and finds a good surface normal evading the influence of the outliers. We judiciously design the cost function so that the outlier will be automatically removed under the assumption that the object's shape and color are smooth. At the end of this paper, we also show some archived 3D data of Segonko Tumulus and objects in the University Museum at The University of Tokyo that were generated by applying the proposed method.

DOI： 10.1007/s11263-009-0262-9

Language：Japanese   Publishing type：Research paper (scientific journal)  

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We have proposed a method for reducing the width of panoramic images with high aspect ratios on the basis of the entropy in local color histograms computed for each column in the images. In this paper, we propose a method for enhancing the entropy in the conventional method to further widen and narrow the regions of high and low entropies, respectively. Experimental results show that the proposed method can reduce the width of panoramic images more effectively than the conventional method.

DOI： 10.3169/itej.63.1622

Language：Japanese   Publishing type：Research paper (scientific journal)  

Trachea and Esophagus Classification by AdaBoost

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

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We present a graph-based image processing algorithm using fast iterative bilateral filters. The computation of bilateral filters is accelerated with fixation of the coefficients during iterations and their approximate decomposition further speeds up the computation. We show that this fixed-coefficient iterative bilateral filter is an alternative solver for optimization problems in graph-based data analyses and apply its fast algorithm to graph-based image processing tasks. Performance of the present algorithm is demonstrated with experiments of contrast enhancement and smoothing of images using cross bilateral filters, in addition to semi-supervised image segmentation and colorization of monochromatic images.

DOI： 10.1007/978-3-540-92957-4_41

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

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2D/3D Registration by Back Projection and Geometrical Constraints

Language：English   Publishing type：Research paper (scientific journal)  

This paper presents a new method for simulating the deformation of organ models by using a neural network. The proposed method is based on the idea proposed by Chen et al. that a deformed model can be estimated from the superposition of basic deformation modes. The neural network finds a relationship between external forces and the models deformed by the forces. The experimental results show that the trained network can achieve a real-time simulation while keeping the acceptable accuracy compared with the nonlinear FEM computation.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

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Fast 3D Shape Reconstruction of Moving Object by Parallel Fast Level Set Method

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

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We describe a non-photorealistic rendering method for generating paper mosaic images that takes into account and compensates for the effects of the thickness and texture of the paper onto which the image is projected. We modulate the brightness of the paper mosaic image on the basis of the emboss-filtered image of the overlapped pieces of paper. We also modulate the brightness of the paper mosaic image on the basis of the paper's texture. That is, we incorporate the effects of the paper's thickness and texture into the resultant paper mosaic image. We experimentally showed that our method increases the three-dimensional sense of depth in paper mosaic images.

DOI： 10.3169/itej.60.2038

Language：English   Publishing type：Research paper (scientific journal)  

A method for increasing the speed of surface shape evolution called the fast narrow band method and a topology-adaptive geometrical modeling method that uses the fast narrow band method are proposed. Although there have been many reports of the use of the level set method as an effective method for topology-adaptive geometrical modeling, the methods suffers from the problem that the computational cost is very large. The narrow band method has been widely used as the most general method for increasing the speed of the level set method, but it has not been found to sufficiently reduce the computational cost. The proposed fast narrow band method retains the precision of the narrow band method while reducing the computational cost by using distance information to increase the efficiency of the search process. Experiments are performed on scenes containing objects with holes and scenes containing multiple objects, and a five-fold increase in speed is achieved over the Hermes algorithm, which was previously the fastest implementation of the level set method.

DOI： 10.1002/scj.20130

Language：English   Publishing type：Research paper (scientific journal)  

We developed a two-scan algorithm for discrete Voronoi tessellations of digital images. The computation time of our method is independent of the number of Voronoi sites. In addition to the previous additively, multiplicatively, compoundly weighted Voronoi diagrams and the additively weighted power Voronoi diagram, we proposed a new weighted Voronoi diagram, namely the compoundly weighted power Voronoi diagram. These five weighted Voronoi diagrams were efficiently computed with our two-scan algorithm.

DOI： 10.3169/itej.60.1072

Language：Japanese   Publishing type：Research paper (scientific journal)  

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DOI： 10.3169/itej.60.1072

Language：English   Publishing type：Research paper (international conference proceedings)  

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3D Tracking of Multiple Moving Objects using Fast Level Set Method

DOI： 10.7210/jrsj.23.813

Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Fast Level Set Method and Realtime Tracking of Moving Objects in a Sequence of Images

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

K. Hara, K. Nishino, K. Ikeuchi,
"Determining Reflectance Parameters from a Single Image under Perspective Projection",
IPSJ Trans. on Computer Vision and Image Media, vol.43, no.SIG 11 (CVIM 5), pp121-129, 2002.

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Level set methods were proposed mainly by mathematicians for constructing a model of a 3D object of arbitrary topology. However, those methods are computationally inefficient due to repeated distance transformations and increased dimensions. In the paper, we propose a new method of modeling fast objects of arbitrary topology by using a surface evolution approach based on mathematical morphology. Given sensor data covering the whole object surface, the method begins with an initial approximation of the object by evolving a closed surface into a model topologically equivalent to the real object. The refined approximation is then performed using energy minimization. The method has been applied in several experiments using range data, and the results are reported in the paper.

DOI： 10.1002/scj.1152

Language：English   Publishing type：Research paper (scientific journal)  

We present a new fast method of modeling 3-D objects of arbitrary topology. The Level Set Methods have been used by many researchers to recover 3-D shapes of arbitrary topology. However, those methods are computationally inefficient. To reduce the computational cost, a new method named FNB (Fast Narrow Band Method) is proposed. FNB is based on the Narrow Band Method (NB) which is the well-known fast method of the Level Set Method. The main idea is to exploit the combinative use of the narrow band and the approximate distance from the front. The method has been applied in several experiments using range data and we find that our method is over 50 times faster than NB.

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Abstract - We have proposed a circular shape of induction type two-dimensional motion motor called the surface induction motor in which the winding is controlled at each coil. For a simpler drive using conventional three-phase inverters, a surface Induction motor with divided windings is proposed, in which one inverter is used for supplying power to one group of windings. Continuously change of thrust direction is verified by using a test machine. The experimental and theoretical results give that the six-division type with three three-phase inverters or eight-division type surface motor supplied by four threephase inverters is best.

DOI： 10.1109/20.800738

Language：English   Publishing type：Research paper (scientific journal)  

The surface induction motor with plural divided windings is proposed to simplify the basic drive method. The characteristics of this type motor are demonstrated both experimentally and theoretically.

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

In the paper, we address the problem of 3-D object modeling that is suitable for graphic display by deriving an optimal approximation to the true object surfaces. A new model generation method is proposed, which obtains a mesh representation of the surfaces by integrating multiple range images with an optimization algorithm based on closeness to the original image data. The method is a relaxation algorithm that achieves accurate shape descriptions gradually by modifying and propagating mesh arrangements iteratively. The paper first presents the formulation within the framework of regularization by redefining the minimization energy function in which both the data closeness and surface smoothness are considered. Next, we give the detailed procedure of the method repeating the surface reconstruction using the chosen regularization parameter at each stage. The search vector field corresponding to range data is generated alternately. The method has been applied to real range images to verify the applicability, and results are reported in the paper.

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Reconstruction of Contour Features and 3-D Surfaces by Using a Statistical Model

Language：English   Publishing type：Research paper (scientific journal)  

The statistical approach using the coupled Markov random field (MRF) and the maximum a posteriori (MAP) estimate has been proposed in order to satisfy both the preservation of local discontinuities and the smoothing of continuous regions for reconstruction of derivative feature measurements and range data. However, this data reconstruction method has some very difficult problems that it is hard to obtain proper results by finding the global optimal solution correctly. Especially, if the ordinary iteration solutions are used for the noisy and rugged data, is it likely that the convergence happens to be at a local optimal solution depending upon the initial value, and the noise smoothing is insufficient or the edge parts are overslurred. To cope with the difficulties, we propose a recovery method that regards the MAP estimation itself as the basic process and do the computation iteratively while controlling smoothing by changing values of the MRF parameters according to some scheduling. The presented algorithm reduces failures because of the local optimization, and is respected to give better results of reconstruction. The applicability of the method has been verified by several reconstruction experiments.

Language：English   Publishing type：Research paper (scientific journal)  

Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.12

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.7

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Event date： 2022.3

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Event date： 2022.3

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Event date： 2022.3

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Event date： 2021.12

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Event date： 2021.11

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Event date： 2021.3

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Event date： 2020.12

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Event date： 2020.9

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Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2019.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kuala Lumpur   Country：Malaysia  

Event date： 2019.8 - 2019.9

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Country：Japan  

Event date： 2019.7 - 2020.8

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Event date： 2019.7 - 2019.8

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Event date： 2019.3

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Event date： 2018.12

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Event date： 2018.11

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Event date： 2018.11

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Event date： 2018.9

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Event date： 2018.9

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Country：Japan  

Event date： 2018.8 - 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2018.8 - 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2018.8 - 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2018.8

Language：English  

Venue：Beijing   Country：China  

Event date： 2018.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Thailand  

Event date： 2018.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Thailand  

Event date： 2018.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Thailand  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.12

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Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.10 - 2017.11

Language：English  

Venue：Beijing   Country：China  

We propose a framework to extend corner feature detection in standard rectangular images with less distortion to distorted circular images captured with fisheye lenses. To solve two problems of nonuniformity of spatial resolution and spherical polar coordinates singularity, our approach makes use of a modification in the Yin-Yang grid, which is an overset grid consisting of two latitude/longitude coordinate systems. The main contribution is to keep the use of existing corner detection programs. Experimental results on synthetic and real images demonstrate the effectiveness of our method.

Event date： 2017.10 - 2017.11

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：China  

Event date： 2017.10 - 2017.11

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：China  

Event date： 2017.10

Language：English  

Venue：Nagoya   Country：Japan  

We propose a reversible data hiding method for embedding secret data in a scaled-up image of a cover image, where the scaled-up image is computed using maximum and minimum filters to achieve higher payload than that of conventional methods based on neighbor mean interpolation. Experimental results show that the proposed method outperforms conventional methods in both data-hiding capacity and image quality.

Event date： 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.8 - 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.8 - 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.8 - 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学   Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学   Country：Japan  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学   Country：Japan  

Event date： 2017.3

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Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.1

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Malaysia  

Event date： 2016.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.12

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.10

Language：English  

Venue：Phuket   Country：Thailand  

We propose two methods for recovering the reflectance spectra of given colorimetric data by using the nonnegative constraints in reflectance spectra. We formulate the problem of reflectance spectra recovery as a non-negative least squares problem and solve it with two iterative methods. Experimental results demonstrate that the two methods give similar recovery results, where Macbeth ColorChecker data are used for recovering the reflectance spectra of Neugebauer primary colors. We also transform the recovered reflectance spectra into tristimulus values to visualize them, where an ad hoc scaling operation is introduced for brightening the recovered colors.

Event date： 2016.9

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2016.9

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Country：Japan  

Event date： 2016.8

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Country：Japan  

Event date： 2016.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学   Country：Japan  

Event date： 2016.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学   Country：Japan  

Event date： 2016.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学   Country：Japan  

Event date： 2016.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学   Country：Japan  

Event date： 2016.1 - 2015.1

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Korea, Republic of  

Event date： 2015.11 - 2014.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2015.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2015.9

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Country：Japan  

Event date： 2015.7

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Event date： 2015.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：姫路市市民会館   Country：Japan  

Event date： 2015.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：姫路市市民会館   Country：Japan  

Event date： 2015.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：姫路市市民会館   Country：Japan  

Event date： 2015.6

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2015.3

Presentation type：Oral presentation (general)  

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Event date： 2015.3

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Event date： 2015.2

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Event date： 2015.1

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Taiwan, Province of China  

Event date： 2014.12

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Country：Japan  

Event date： 2014.12

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Event date： 2014.12

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Event date： 2014.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.8 - 2016.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.8 - 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.8 - 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学国際会議場   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学国際会議場   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学国際会議場   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学国際会議場   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学国際会議場   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学国際会議場   Country：Japan  

Event date： 2014.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学国際会議場   Country：Japan  

Event date： 2014.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.2

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.2

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.12

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.12

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：United States  

Event date： 2013.12

Language：English  

Venue：San Jose, CA   Country：United States  

We propose a new error diffusion method based on integral images. The proposed method has only 3 error diffusion coefficients, and therefore is computationally efficient compared to the conventional error diffusion methods. Experimental results show that the proposed method is fast while keeping the halftone quality.

Event date： 2013.12

Language：English  

Venue：Kyoto   Country：Japan  

Recently, two methods for removing high density salt-and-pepper noise in images have been proposed by Esakkirajan et al. and Hong et al. However, their methods have not been yet compared experimentally. In this paper, we compare them and show some experimental results. Additionally, we propose a hybrid method which is derived by combining the two methods, and experimentally show that the proposed method achieves higher values of both peak signal-to-noise ratio (PSNR) and image enhancement factor (IEF) than the two methods.

Event date： 2013.12

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2013.11

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.11

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2013.11

Language：English  

Venue：Naha, Okinawa   Country：Japan  

We propose a memory-efficient method for computing high-dimensional integral images. The proposed method generates exactly the same integral images as that generated by the conventional method, while using less memory. Experimental results show the effectiveness of the proposed method.

Event date： 2013.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.7

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.1

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2013.1

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.12

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2012.11

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.11

Language：English  

Venue：Hiroshima   Country：Japan  

Recently, two-dimensional principal component analysis (2D-PCA) and its variants have been proposed by several researchers. In this paper, we summarize their 2DPCA variants, show some equivalence among them, and present a unified view in which the non-iterative 2DPCA variants are interpreted as the non-iterative approximate algorithms for the iterative 2DPCA variants, i.e., the non-iterative 2DPCA variants are derived as the first iterations of the iterative algorithm started from different initial settings. Then we classify the non-iterative 2DPCA variants on the basis of their algorithmic patterns and propose a new non-iterative 2DPCA algorithm based on the classification. The effectiveness of the proposed algorithm is experimentally demonstrated on three publicly accessible face image databases.

Event date： 2012.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2012.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2012.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.8

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.7

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2012.3

Language：English  

Venue：Kyoto   Country：Japan  

Recently, the generalized low rank approximations of matrices (GLRAM) have been proposed for dimensionality reduction of matrices such as images. However, in GLRAM, it is necessary for users to specify the numbers of rows and columns in low rank matrices. In this paper, we propose a method for determining them semiautomatically by symmetrizing GLRAM. Experimental results show that the proposed method can determine the optimal ranks of matrices while achieving competitive approximation performance.

Event date： 2011.7

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2011.7

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2011.7

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2011.7

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2011.7

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2011.7

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

物体の幾何形状と光源状況の両方またはいずれか一方を既知として物体の画像から物体表面の反射特性を推定する手法がこれまでに提案されてきたが，これらの手法の多くでは，異なる視線・光源方向や偏光状況下で物体を撮影した複数枚の画像を入力する必要があった．本論文では，一枚の画像から物体表面の反射特性とテクスチャを同時推定する手法を提案している．提案される手法では，反射特性の空間的均一性を仮定したうえで，反射パラメータの値を連続的に変化させて得られる拡散反射拡散反射テクスチャの集合の中から，ヒストグラムの頻度をべき乗変換した擬似ヒストグラムのエントロピーが最小の拡散反射拡散反射テクスチャを探索する．合成画像と実画像に対して本手法の有効性を示している．

Event date： 2010.11

Language：English  

Venue：Fukuoka   Country：Japan  

We propose a method for clipping a rectangular region from an image by minimizing a weighted intersection of two color histograms which are constructed with pixels included in the inside and the outside of the rectangular region. Furthermore, we extend the clipping method for images to that for videos. Experimental results show that the proposed method can clip the regions of objects from images and remove the regions of backgrounds.

Event date： 2010.11

Language：English  

Venue：Fukuoka   Country：Japan  

We propose a method for removing rows and columns in an image by clustering the sets of rows and columns separately. We also propose a method for adding rows and columns to an image on the basis of the proposed row/column removal method. Experimental results show that the proposed methods can reduce or enlarge the sizes of given images, while the aspect ratios of the main objects in the images are preserved.

Event date： 2009.9 - 2009.10

Language：English  

Venue：Kyoto   Country：Japan  

We propose two methods for robustifying multilinear principal component analysis (MPCA) which is an extension of the conventional PCA for reducing the dimensions of vectors to higher-order tensors. For two kinds of outliers, i.e., sample outliers and intra-sample outliers, we derive iterative algorithms on the basis of the Lagrange multipliers. We also demonstrate that the proposed methods outperform the original MPCA when datasets contain such outliers experimentally.

Event date： 2009.6

Language：English  

Venue：Miami, FL   Country：United States  

Estimating the illumination and the reflectance properties of an object surface from a sparse set of images is an important but inherently ill-posed problem. The problem becomes even harder if we wish to account for the spatial variation of material properties on the surface. In this paper, we derive a novel method for estimating the spatially varying specular reflectance properties, of a surface of known geometry, as well as the illumination distribution from a specular-only image, for instance, captured using polarization to separate reflection components. Unlike previous work, we do not assume the illumination to be a single point light source. We model specular reflection with a spherical statistical distribution and encode the spatial variation with radial basis functions of its parameters. This allows us to formulate the simultaneous estimation of spatially varying specular reflectance and illumination as a sound probabilistic inference problem, in particular, using Csisźar's I-divergence measure. To solve it, we derive an iterative algorithm similar to expectation maximization. We demonstrate the effectiveness of the method on synthetic and real-world scenes.

Event date： 2009.4

Language：English  

Venue：Taipei   Country：Taiwan, Province of China  

In the paper, we propose a new method for blind separation of an arbitrary number of images from a set of their linear mixtures with unknown coefficients. This approach is as follows. We first introduce a novel multiple correlation between one image and a set of multiple images. Then this multiple correlation leads us to provide a set of simultaneous linear equations for updating each mixture of images. Finally, source images are recovered by iterating between solving the sets of equations and cyclically permuting the mixtures of images. The technique can be applied for extracting multiple layers from images containing multiple reflections and transparency.

Event date： 2009.1

Language：English  

Venue：Tokyo   Country：Japan  

We propose simultaneous low rank approximation of tensors (SLRAT) for the dimensionality reduction of tensors and modify it to the robust one, i.e., the robust SLRAT. For both the SLRAT and the robust SLRAT, we propose iterative algorithms for solving them. It is experimentally shown that the robust SLRAT achieves lower reconstruction error than the SLRAT when a dataset contains noise data. We also propose a method for classifying sets of tensors and call it the subspace matching, where both training data and testing data are represented by their subspaces, and each testing datum is classified on the basis of the similarity between subspaces. It is experimentally verified that the robust SLRAT achieves higher recognition rate than the SLRAT when the testing data contain noise data.

Event date： 2008.9

Language：English  

Venue：New York, NY   Country：United States  

This paper presents a new method for simulating the deformation of organ models by using a neural network. The proposed method is based on the idea proposed by Chen et al. [2] that a deformed model can be estimated from the superposition of basic deformation modes. The neural network finds a relationship between external forces and the models deformed by the forces. The experimental results show that the trained network can achieve a real-time simulation while keeping the acceptable accuracy compared with the nonlinear FEM computation.

Event date： 2008.5

Language：English  

Venue：Pasadena, CA   Country：United States  

This paper presents a parallel algorithm of the Level Set Method named the Parallel Fast Level Set Method, and its application for real-time 3D reconstruction of human shape and motion. The Fast Level Set Method is an efficient implementation algorithm of the Level Set Method and has been applied to several applications such as object tracking in video images and 3D shape reconstruction using multiple stereo cameras. In this paper, we implement the Fast Level Set Method on a PC cluster and develop a real-time motion capture system for arbitrary viewpoint image synthesis. To obtain high performance on a PC cluster, efficient load-balancing and resource allocation algorithms are crucial problems. We develop a novel optimization technique of load distribution based on the estimation of moving direction of object boundaries. In this technique, the boundary motion is estimated in the framework of the Fast Level Set Method, and the optimum load distribution is predicted and performed according to the estimated boundary motion and the current load balance. Experiments of human shape reconstruction and arbitrary viewpoint image synthesis using the proposed system are successfully carried out.

Event date： 2007.9

Language：English  

Venue：San Antonio, TX   Country：United States  

The Chan-Vese level set algorithm has been successfully applied to segmentation of images on Cartesian coordinate meshes, including ordinary planar images. In this paper we present a Chan-Vese model for segmentation of images on polar coordinate meshes, such as topography and remote sensing images. The image segmentation is accomplished by formulating the associated evolution equation in the polar coordinate system and then numerically solving the partial differential equation on an overset grid system called the Yin-Yang grid, which is free from the problem of singularity at the poles. We include examples of segmentations of real earth data that demonstrate the performance of our method.

Event date： 2007.8

Language：English  

Venue：Montreal, QC   Country：Canada  

This paper presents a new registration algorithm of a 2D image and a 3D geometrical model, which is robust for initial registration errors, for reconstructing a realistic 3D model of indoor scene settings. One of the typical techniques of pose estimation of a 3D model in a 2D image is the method based on the correspondences between 2D photometrical edges and 3D geometrical edges projected on the 2D image. However, for indoor settings, features extracted on the 2D image and jump edges of the geometrical model, which can be extracted robustly, are limited. Therefore, it is difficult to find corresponding edges between the 2D image and the 3D model correctly. For this reason, in most cases, the relative position has to be manually set close to correct position beforehand. To overcome this problem, in the proposed method, firstly the relative pose is roughly estimated by utilizing geometrical consistencies of back-projected 2D photometrical edges on a 3D model. Next, the edge-based method is applied for the precise pose estimation after the above estimation procedure is converged. The performance of the proposed method is successfully demonstrated with some experiments using simulated models of indoor scene settings and actual environments measured by range and image sensors.

Event date： 2007.8

Language：Japanese  

Venue：Montreal, QC   Country：Canada  

Event date： 2007.3

Language：English  

Venue：Barcelona   Country：Spain  

Looking through a window, the object behind the window is often disturbed by a reflection of another object. In the paper, we present a new method for separating reflections from a single image. Most existing techniques require the programmer to create an image database or require the user to manually provide the position and layer information of feature points in the input image, and thus suffer from being extremely laborious. Our method is realized by classifying edges in the input image based on the belonging layer and formalizing the problem of decomposing the single image into two layer images as an optimization problem easier to solve based on this classification, and then solving this optimization with a pyramid structure and deterministic annealing. As a result, we are able to accomplish almost fully automated separation of reflections from a single image.

Event date： 2006.5

Language：English  

Venue：Orlando, FL   Country：United States  

This paper introduces a new motion capture system for recovering 3D models of multiple persons separately and robustly against occlusion in real-time. Various markerless motion capture systems using video cameras have been proposed so far. However, in case that there are multiple persons in the scene at the same time, it is quite difficult to reconstruct a precise 3D model of each person separately due to the occlusion between them. To deal with this problem, the Fast Level Set Method is utilized in the proposed system for integrating stereo range data which is captured by multiple stereo cameras located around the target people. To reconstruct precise 3D models in real-time, the proposed system is implemented on a PC cluster with seven PCs and four stereo cameras. Tracking experiment of multiple persons and real-time reconstruction of 3D human models using the proposed system are successfully carried out.

Event date： 2005.10

Language：English  

Venue：Beijing   Country：China  

In this paper, we propose a new method for simultaneously estimating the illumination of the scene and the reflectance property of the object from a single image. We assume that the illumination consists of multiple point sources and the shape of the object is known. Unlike previous methods, we will recover not only the direction and intensity of the light sources, but also the number of light sources and the specular reflection parameter of the object. First, we represent the illumination on the surface of a unit sphere as a finite mixture of von Mises-Fisher distributions by deriving a spherical specular reflection model. Next, we estimate this mixture and the number of distributions. Finally, using this result as initial estimates, we refine the estimates using the original specular reflection model. We can use the results to render the object under novel lighting conditions.

Event date： 2005.5

Language：English  

Venue：Tsukuba Science City   Country：Japan  

In the paper, we present a new method of converting a photo image to a synthesized painting image following the painting style of an example painting image.The proposed method uses a hierarchical and adaptive patch-based approach to both the synthesis of painting styles and preservation of scene details.This approach can be summarized as follows. The input photo image is represented as a set of patches divided adaptively using a distance transform technique. Then the mapping between the input photo and example painting images is efficiently inferred using Bayesian belief propagation recursively.

Event date： 2005.5

Language：Japanese  

Venue：Tsukuba Science City   Country：Japan  

Event date： 2005.5

Language：English  

Venue：Tsukuba Science City   Country：Japan  

Event date： 2004.10

Language：Japanese  

Venue：The Hague   Country：Netherlands  

Event date： 2004.10

Language：Japanese  

Venue：The Hague   Country：Netherlands  

Event date： 2004.10

Language：English  

Venue：The Hague   Country：Netherlands  

The level set method (LSM) has been widely used for various applications such as motion tracking and 3D geometrical modeling. However, the calculation cost of reinitialization and updating of an implicit function is considerably expensive as compared with conventional active contour models such as "Snakes". To tackle this problem, we propose an ef cient algorithm of the LSM named the Fast Level Set Method(FLSM). This paper introduces some experiments based on the FLSM, including 2D real-time tracking of moving objects in video images, and 3D simultaneous motion capture system of multiple targets using stereo range images.

Event date： 2004.10

Language：Japanese  

Venue：The Hague   Country：Netherlands  

Event date： 2003.10

Language：Japanese  

Venue：Nice   Country：France  

Event date： 2003.10

Language：Japanese  

Venue：Nice   Country：France  

Event date： 2003.10

Language：English  

Venue：Nice   Country：France  

Event date： 2003.10

Language：Japanese  

Venue：Nice   Country：France  

Event date： 2003.10

Language：English  

Venue：Nice   Country：France  

Several techniques have been developed for recovering reflectance properties of real surfaces under unknown illumination conditions. However, in most cases, those techniques assume that the light sources are located at infinity, which cannot be applied to, for example, photometric modeling of indoor environments. In this paper, we propose two methods to estimate the surface reflectance property of an object, as well as the position of a light source from a single image without the distant illumination assumption. Given a color image of an object with specular reflection as an input, the first method estimates the light source position by fitting to the Lambertian diffuse component, while separating the specular and diffuse components by using an iterative relaxation scheme. Moreover, we extend the above method by using a single specular image as an input, thus removing its constraints on the diffuse reflectance property and the number of light sources. This method simultaneously recovers the reflectance properties and the light source positions by optimizing the linearity of a log-transformed Torrance-Sparrow model. By estimating the object's reflectance property and the light source position, we can freely generate synthetic images of the target object under arbitrary source directions and source-surface distances.

Event date： 2003.10

Language：English  

Venue：Nice   Country：France  

This paper presents a method to estimate geometrical, photometrical, and environmental information of a singleviewed object in one integrated framework under fixed viewing position and fixed illumination direction. These three types of information are important to render a photorealistic image of a real object. Photometrical information represents the texture and the surface roughness of an object, while geometrical and environmental information represent the 3D sliape of an object and the illumination distribution, respectively. The proposed method estimates the 3D shape by computing the surface normal from polarization data, calculates the texture of the object from the diffuse only reflection component, determines the illumination directions from the position of the brightest intensity in the specular reflection component, and finally computes the surface roughness of the object by using the estimated illumination distribution.

Event date： 2003.10

Language：Japanese  

Venue：Nice   Country：France  

Event date： 2003.10

Language：English  

Venue：Nice   Country：France  

Event date： 1999.10

Language：English  

Venue：Kobe, Jpn   Country：Other  

Level set methods were proposed mainly by mathematicians for extracting bounding contours of multiple regions or shapes with holes. In the paper, we propose a new method of constructing a surface/solid model of a 3-D object of arbitrary topology on the basis of the approach. Given sensor data covering the whole object surface, the method begins with an initial approximation of the object by evolving a closed-surface into a model topologically equivalent to the real object. The refined approximation is then performed by deforming it at an optimally tuned speed. By numerically solving the level set equations for tracking the evolving surfaces, it becomes possible to handle 3-D objects of arbitrary topology while maintaining high accuracy in the shape fitting.

Event date： 1999.10

Language：English  

Venue：Kobe, Jpn   Country：Other  

Language：English  

Country：Other  

An impedance model following force control, using a position/orientation compensator based on joystick taught data, is proposed for an industrial robot with an open architecture controller. The method is characterized by two requirements: 1) to polish an object with the desired contact force and orientation; and 2) no conventional complicated teaching process is required. The effectiveness and potential of the proposed method are demonstrated through some experiments concerning with a polishing task using the JS-10 industrial robot.

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Japan