Recently, it becomes popular to synthesize new viewpoint images based on some sampled viewpoint images of real scene using technique of computer vision. 3D shape reconstruction in Euclidean space is not necessarily required, but information of dense matching points is basically enough to synthesize new viewpoint images. In this paper, we propose a new method for 3D reconstruction from three cameras based on projective geometry. In the proposed method, three input camera images are rectified based on projective geometry, so that the vertical and horizontal directions can be completely aligned with the epipolar planes between the cameras. This rectification provides Projective Voxel Space (PVS), in which the three axes are aligned with the directions of camera projection. Such alignment simplifies the procedure for projection between the 3D space and the image planes in PVS. Taking this advantage of PVS, silhouettes of the objects are projected into PVS, so that the searching area of matching points can be reduced. The consistency of color value between the images is also evaluated for final determination of the matching point. The finally acquired matching points in the proposed method are described as the surface of the objects in PVS. The acquired surface of the objects in PVS also includes knowledge about occlusion. Finally, images from new viewpoints can be synthesized from the matching points and occlusions. Although the proposed method requires only weak calibration, plausible occlusions are also synthesized in the images. In the experiments, images of virtual viewpoints, which were set among three cameras, are synthesized from three real images.
Shinji FUKUI Yuji IWAHORI Robert J. WOODHAM Kenji FUNAHASHI Akira IWATA
This paper proposes a new method to recover the sign of local Gaussian curvature from multiple (more than three) shading images. The information required to recover the sign of Gaussian curvature is obtained by applying Principal Components Analysis (PCA) to the normalized irradiance measurements. The sign of the Gaussian curvature is recovered based on the relative orientation of measurements obtained on a local five point test pattern to those in the 2-D subspace called the eigen plane. Using multiple shading images gives a more accurate and robust result and minimizes the effect of shadows by allowing a larger area of the visible surface to be analyzed compared to methods using only three shading images. Furthermore, it allows the method to be applied to specular surfaces. Since PCA removes linear correlation among images, the method can produce results of high quality even when the light source directions are not widely dispersed.
Wavelet based image compression is getting popular due to its promising compaction properties at low bitrate. Zerotree wavelet image coding scheme efficiently exploits multi-level redundancy present in transformed data to minimize coding bits. In this paper, a new technique is proposed to achieve high compression by adding new zerotree and significant symbols to original EZW coder. Contrary to four symbols present in basic EZW scheme, the modified algorithm uses eight symbols to generate fewer bits for a given data. Subordinate pass of EZW is eliminated and replaced with fixed residual value transmission for easy implementation. This modification simplifies the coding technique as well and speeds up the process, retaining the property of embeddedness.
It has been over a decade since the "Eigenfaces" approach to automatic face recognition, and other appearance-based methods, made an impression on the computer vision research community and helped spur interest in vision systems being used to support biometrics and human-computer interface. In this paper I give a personal view of the original motivation for the work, some of the strengths and limitation of the approach, and progress in the years since. Appearance-based approaches to recognition complement feature- or shape-based approaches, and a practical face recognition system should have elements of both. Eigenfaces is not a general approach to recognition, but rather one tool out of many to be applied and evaluated in the appropriate context.
Yoshitaka TAKASAKI Katsuyoshi ITO
Transmission and distribution systems are investigated for application in future fiber optic super-broadband and super-multi-channel subscriber loops. Gradual upgrading is considered so that future systems can keep compatibility with existing systems. First, time frame and strategies for subscriber loop upgrade are overviewed and assumptions for evolution of broadband multimedia distribution systems are discussed. It is suggested that upgrading to super-high definition (SHD) quality multimedia is desirable. Next, some examples of extra-auxiliary picture (EAP) formats are discussed to show the possibility of improving upgradability and compatibility by using extra-channels. Then multiplexing and channel selecting systems are investigated for economical realization of super-multi-channel distribution and flexible channel selection, and hybrid multiplexing (HMUX) and a trans-selector (T-SEL) are proposed. Finally, the efficiencies of HMUX and T-SEL are discussed by using numerical examples. Although broadband down streams are mainly considered, other streams such as IP traffics can be accommodated in the distribution systems investigated in this paper.
Takashi OKUMA Takeshi KURATA Katsuhiko SAKAUE
In this paper, we describe a method for estimating external camera parameters in real time. We investigated the effectiveness of this method for annotating real scenes with 3-D virtual objects on a wearable computer. The proposed method enables determining known natural feature points of objects through multiplied color histogram matching and template matching. This external-camera-parameter calculation method consists of three algorithms for PnP problems, and it uses each algorithm selectively. We implemented an experimental system based on our method on a wearable vision system. This experimental system can annotate real objects with 3D virtual objects by using the proposed method. The system was implemented in order to enable effective annotation in a mixed-reality environment on a wearable computing system. The system consists of an ultra small CCD camera set at the user's eye, an ultra small display, and a computer. This computer uses the proposed method to determine the camera parameters. It then renders virtual objects based on the camera parameters and synthesizes images on a display. The system works at 10 frames per second.
Kazuhiro HANE Minoru SASAKI JongHyeong SONG Yohei TAGUCHI Kosuke MIURA
Fiber-optic MEMS which is fabricated by combining direct photo-lithography of optical fiber and silicon micro-machining is proposed. Preliminary results of micro-machining of optical fiber and variable telecommunication devices are presented.
Koichi SATO Hiroyoshi YAMADA Yoshio YAMAGUCHI
In this paper, we examine the polarimetric characteristics and the potential of the coherent decomposition in polarimetric synthetic aperture radar (SAR) interferometry. Coherent scattering decomposition based on the coherence optimization can separate effective phase center of different scattering mechanisms and can be used to generate canopy digital elevation model (DEM). This decomposition is applied to a simplified stochastic scattering model such as forest canopy. However, since the polarimetric characteristics are not well understood when the decomposition is carried out, we investigate its characteristics and potential using polarimetric entropy-alpha and three-component scattering matrix decomposition. The results show that the first and third components correspond to the lower and upper layer, respectively, in ideal case. In this investigation, SIR-C/X-SAR data of the Tien Shan flight-pass are used.
Kazuhiko USHIO Hideaki FUJIMOTO
Let t and n be positive integers. We show that the necessary and sufficient condition for the existence of a balanced t-foil decomposition of the complete graph Kn is n 1 (mod 6t). Decomposition algorithms are also given.
Complex-valued region-based-coupling image clustering (continuous soft segmentation) neural networks are proposed for interferometric radar image processing. They deal with the amplitude and phase information of radar data as a combined complex-amplitude image. Thereby, not only the reflectance but also the distance (optical length) are consistently taken into account for the clustering process. A continuous complex-valued label is employed whose structure is the same as that of input raw data and estimation image. Experiments demonstrate successfully the clustering operations for interferometric synthetic aperture radar (InSAR) images. The method is applicable also to future radar systems for image acquisition in, e.g., invisible fire smoke places and intelligent transportation systems by generating a processed image more recognizable by human and automatic recognition machine.
A digital noncoherent demodulation scheme is presented for reception of Gaussian frequency shift keying (GFSK) signals with small modulation index. The proposed differential demodulator utilizes oversampled signals to estimate the symbol timing and to compensate the frequency offset. The performance of the proposed receiver is evaluated in terms of the bit-error rate (BER). Numerical results show that the proposed demodulator provides performance comparable to that of conventional baseband differential demodulator, while significantly reducing the implementation complexity suitable for single chip integration with direct conversion radio frequency module. Finally the performance of the proposed receiver is improved by adding a simple decision feedback module.
Shiao-Li TSAO Meng Chang CHEN Yeali Sunny SUN
Disk-zoning technique has been widely adopted to increase disks capacities. As a result of disparity of capacities of inner and outer zones, the data transfer rates of the outer zones of a zoned-disk are higher than the inner zones that post a great challenge for zoned-disk based multimedia playback. In this paper, we study the data placement problem of VBR (variable bit rate) videos on zoned-disks. Our objective is to minimize video server buffer size and simultaneously to maximize disk utilization subject to the zone constraints of disk. We introduce the CRT (constant read time) method that allocates each user a constant time period in every service round to retrieve a variable-sized disk block. The CRT method can be formulated as constrained combinatorial problems that its optimum solution can be obtained by employing dynamic programming. Two heuristics are also explored to reduce time and space complexities. According to experiment results, the heuristic algorithms obtain near optimum solutions with shorter computation time.
Techniques for human-motion recovery are applicable to a variety of areas, such as sports, dancing, virtual reality, and video-game production. The people who work in this area focus their attention on recovering information on the motion of individuals rather than groups of people. It is important to demonstrate the possibility of recovering descriptions of the 3-D motion in team sports, since such information is able to provide us with a variety of information on the relations among players. This paper presents a new experimental result on 3-D motion recovery from a team sport. The result was obtained by a non-rigid shape recovery technique based on images from uncalibrated cameras. The technique was applied to recovering the 3-D motion of the players in a mini-basketball game which was played in a gymnasium. Some attention is focused on the analysis of the players' motion. Satisfactory results were obtained.
Albert Peter BLICHER Sbastien ROY
We describe a method for object recognition with 2D image queries to be identified from among a set of 3D models. The pose is known from a previous step. The main target application is face recognition. The 3D models consist of both shape and color texture information, and the 2D queries are color camera images. The kernel of the method consists of a lookup table that associates 3D surface normals with expected image brightness, modulo albedo, for a given query. This lookup table is fast to compute, and is used to render images from the models for a sum of square difference error measure. Using a data set of 42 face models and 1764 (high quality) query images under 7 poses and 6 lighting conditions, we achieve average recognition accuracy of about 83%, with more than 90% in several pose/lighting conditions, using semi-automatically computed poses. The method is extremely fast compared to those that involve finding eigenvectors or solving constrained equation systems.
Kiyotaka FUJISAKI Shizu TATSUMOTO Mitsuo TATEIBA
This paper presents methods for estimating the ocean wavelength in satellite altimetry and discusses the possibility of detecting the ocean wavelength. Numerical analyses show that there exists a relation between the significant wavelength and the pulse-to-pulse correlation coefficient. Presented methods are based on processing the data of existing satellite altimeters. Accordingly, we will be able to propose a method for measuring the wavelength without a large change in existing altimetry system.
Takashi HISAKADO Kohshi OKUMURA
This paper describes how the symmetry of a three-phase circuit prevents the symmetric modes of several subharmonic oscillations. First, we make mathematically it clear that the generation of symmetrical 1/3l-subharmonic oscillations (l=1,2,) are impossible in the three-phase circuit. As far as 1/(3l+1)-subharmonic oscillations (l=1,2,) and 1/(3l+2)-subharmonic oscillations (l=0,1,) are concerned, the former in negative-phase sequence and the latter in positive-phase sequence are shown to be impossible. Further, in order to confirm the above results, we apply the method of interval analysis to the circuit equations and obtain all steady state solutions with unsymmetric modes.
Hiroaki SUZUKI Hiroyuki KAWAI Hiroshi MAKINO Yoshio MATSUDA
A VLIW (Very Long Instruction Word) architecture with a new code compaction method has been proposed. For a 3D-geometry processor, we consider two types of 2-issue VLIW architectures, the floating-point execution accelerating VLIW (FP-VLIW) and the data-move enhancing VLIW (MV-VLIW) architectures, as expansions of a Single-Streaming Single Instruction, Multiple Data (SS-SIMD) architecture. To solve the code bloat problem which is common to VLIW architectures, the proposed method makes it possible to compact original codes into the VLIW codes by software tools and decompact the VLIW codes by a simple hardware decompactor composed of an instruction swap circuit on a chip. Speeds and code densities of the two VLIWs with the code compaction are compared to the SS-SIMD with the same instruction set and the same building blocks. The FP-VLIW shows the fastest speed performance in the evaluation results of the viewperf CDRS-03 benchmark programs. It is 36% faster than the SS-SIMD used as reference. The proposed compaction method keeps the 95% code density of the SS-SIMD. One test program shows that the code density of the MV-VLIW is higher than that of the SS-SIMD. This result demonstrates that the merit of compacting nops can be greater than the VLIW penalty. The FP-VLIW architecture with the code compaction achieves 1.36 times the speed performance without significant code-density deterioration.
There exist some results showing that quantum communications are more powerful than classical communications. Moreover, although quantum entangled states do not give extra information, by using prior entanglement the quantum communication complexity of some functions is less than the classical communication complexity. The communications with prior entanglement can be regarded as a type of public coin models. In this paper, we investigate quantum communications for multi-party with prior entanglement, and show that there exists a generalized inner product function for k-party such that the quantum communication complexity is at most k bits, but the classical communication complexity needs at least 3k/2 bits. Moreover, we also provide a generalized form of prior entanglements that is effective in order to compute some type of Boolean functions.
Distributed domino effect-free checkpointing techniques can be divided into two categories: coordinated and communication-induced checkpointing. The former is inappropriate for mobile computing systems because it either forces every mobile host to take a new checkpoint or blocks the underlying computation during the checkpointing process. The latter makes every mobile host take the checkpoint independently. However, each mobile host may need to store multiple local checkpoints in stable storage. This investigation presents a novel three level synchronous checkpointing algorithm that combines the advantages of above two methods for mobile computing systems. The algorithm utilizes pre-synchronization, quasi-synchronization, and post-synchronization techniques and has the following merits: (1) Consistent global checkpoints can be ensured. (2) No mobile host is blocked during checkpointing. (3) Only twice the checkpoint size is required. (4) Power consumption is low. (5) The disconnection problem of mobile hosts can be resolved. (6) Very few mobile hosts in doze mode are disturbed. (7) It is simple and easy to implement. The proposed algorithm's numerical results are also provided in this work for comparison. The comparison reveals that our algorithm outperforms other algorithms in terms of checkpoint overhead, maintained checkpoints, power consumption, and disturbed mobile hosts.
Shigeru YAMASHITA Hiroshi SAWADA Akira NAGOYA
This paper presents a new framework for synthesizing look-up table (LUT) networks. Some of the existing LUT network synthesis methods are based on one or two functional (Boolean) decompositions. Our method also uses functional decompositions, but we try to use various decomposition methods, which include algebraic decompositions. Therefore, this method can be thought of as a general framework for synthesizing LUT networks by integrating various decomposition methods. We use a cost database file which is a unique characteristic in our method. We also present comparisons between our method and some well-known LUT network synthesis methods, and evaluate the final results after placement and routing. Although our method is rather heuristic in nature, the experimental results are encouraging.