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High performance computing for parallel rendering in surgical autostereoscopic display and navigation

International Congress Series 2003年 1256卷 403-407页

作者： Nobuyuki Sakai Nobuhiko Hata Hongen Liao Takeyoshi Dohi Graduate School of Information Science and Technology The University of Tokyo 7-3-1 Hongo Bunkyo Tokyo 113-8656 Japan

The three-dimensional medical information obtained from Magnetic Resonance image (MRI), X-ray Computed Tomography (CT), etc. is used for an operation-supporting image, and operations under image guidance have also been conducted. One of the stereoscopic methods is Integral Videography (iv), which is an animated extension of Integral Photography, reproducing a computer-generated graphical object. Though the advantage of iv has been proven in both feasibility studies and clinical applications, one of the issues still unsolved is the notable quantity of calculation that causes significant delay in rendering. Then using parallel processing method integrating Message Passing Interface (MPI) on High Performance Computer (HPC), we shortened the calculating time of iv picture by the shortest at about 0.2 s. Furthermore, by using socket communication, it transmitted to another portable note PC, which is for a display. Then, we achieved the fast presentation of autostereoscopic images seen from an arbitrary direction that was specified with the mouse from the note PC side at anywhere we can access to the network.

关键词： parallel rendering Integral videography High performance computing

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High performance missing data detection and interpolation for video compression and restoration applications

High performance missing data detection and interpolation fo...

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International Symposium on parallel and distributed processing (IPDPS)

作者： M. Ceccarelli G. Laccetti A. Petrosino University of Sannio Benevento Italy DMA Naples Italy ICAR-CNR Naples Italy

In this paper, we explore the use of motion estimation methods to restore noisy motion pictures coming from degraded film within the framework of high-performance computing environments. Specifically, we investigate how the use of block-matching methods can outperform gradient-based methods (which are more sensible to little movements) also in the case of blotch detection in degraded film. Also, we show how a proposed method characterized by the use of a set of features together with multiresolution can be at the same time robust to noise and effective in motion compensated filtering, mainly concerning films that contain both large amounts of noise and fast/large motion objects in their frames. The peculiarities of the method are discussed and the model performance is assessed and compared with examples.

关键词： Interpolation Video compression image restoration Motion pictures Degradation Forward error correction Signal restoration Motion detection Motion estimation Working environment noise

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A general framework for searching in distributed data repositories

A general framework for searching in distributed data reposi...

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International Symposium on parallel and distributed processing (IPDPS)

作者： S. Bakiras P. Kalnis T. Loukopoulos Wee Siong Ng Department of Electrical & Electronic Engineering University of Hong Kong Hong Kong China School of Computing National University of Singapore Singapore Department of Computer Science Hong Kong University of Science and Technology Hong Kong China

This paper proposes a general framework for searching large distributed repositories. Examples of such repositories include sites with music/video content, distributed digital libraries, distributed caching systems, etc. The framework is based on the concept of neighborhood; each client keeps a list of the most beneficial sites according to past experience, which are visited first when the client searches for some particular content. Exploration methods continuously update the neighborhoods in order to follow changes in access patterns. Depending on the application, several variations of search and exploration processes are proposed. Experimental evaluation demonstrates the benefits of the framework in different scenarios.

关键词： Peer to peer computing Network servers distributed computing Drives Computer science Software libraries Internet Publishing image databases Video sharing

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parallel algorithm based on a frequential decomposition for dynamic 3D computed tomography

Parallel algorithm based on a frequential decomposition for ...

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International Symposium on parallel and distributed processing (IPDPS)

作者： T. Rodet L. Desbat P. Grangeat IAB Faculté de médecine UJF TIMC-IMAG UMR CNRS 5525 La Tronche France LETI-DSIS-DRT-CEA Grenoble France

We present a tomographic reconstruction algorithm based on a frequential decomposition of the data. We show that the frequential components of the attenuation function to be identified can be reconstructed from the frequential decomposition of the data. Moreover, downsampling techniques added to the identification of null components and coupled to compression techniques, speed up the reconstruction time up to six compared to the classical FBP. We identify the optimal number of frequential components. We show reconstructions from real data. A parallel implementation of our new algorithm is then proposed and evaluated on two small PC clusters.

关键词： parallel algorithms Computed tomography Fourier transforms image reconstruction Surgery Reconstruction algorithms Attenuation Content addressable storage Filters Sampling methods

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MedIGrid: a medical imaging application for computational Grids

MedIGrid: a medical imaging application for computational Gr...

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International Symposium on parallel and distributed processing (IPDPS)

作者： M. Bertero P. Bonetto L. Carracciuolo L. D'Amore A. Formiconi M.R. Guarracino G. Laccetti A. Murli G. Oliva Department of Computer and Information Science University of Genoa Italy Institute for High Performance Computing and Networking CNR Naples Italy Department of Mathematics and Applications University of Napoli Federico II Italy Department of Clinical Phisiopatology University of Florence Italy

In the last decades, diagnosing medical images has heavily relied on digital imaging. As a consequence, huge amounts of data produced by modern medical instruments need to be processed, organized, and visualized in a suitable response time. Many efforts have been devoted to the development of digital Picture Archiving and Communications Systems (PACS) which archive and distribute image information across a hospital and provide Web access to avoid the expensive deployment of a large number of such systems. On the other hand, this approach does not solve problems related to the increasing demand of high performance computing and storage facilities, which cannot be placed within a hospital. In this work we describe MedIGrid, an application that enables nuclear doctors to transparently use high performance computers and storage systems for the PET/SPECT (Positron Emission Tomography/Single Photon Emission Computed Tomography) image processing, management, visualization and analysis. MedIGrid is the result of the joint efforts of a group of researchers committed to the development of a distributed application to test and deploy new reconstruction methods in clinical environments. The outcomes of this work include a set of platform independent software tools to read medical images, control the execution of computing intensive tomographic algorithms, and explore the reconstructed tomographic volumes. In the paper we describe how the collaboration among different research groups has contributed to the integration of the application into a single framework. The results of our work are discussed.

关键词： Biomedical imaging Computer applications Grid computing Medical diagnostic imaging Application software Picture archiving and communication systems Hospitals High performance computing image storage Positron emission tomography

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Transform-based image compression by noise reduction and spatial modification using Boolean minimization

Transform-based image compression by noise reduction and spa...

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IEEE/SP Workshop on Statistical Signal processing (SSP)

作者： S.S. Agauan T.A. Baran K.A. Panetta Dept. of Electr. Eng. Texas Univ. San Antonio TX USA Tufts University Electrical and Computer Engineering Medford MA USA

A method for the lossy compression of multivalued images using transform-based Boolean minimization is described. Blocks in bit-planes of an image are minimized, and the results of these minimizations are used to detect and reduce noise (sandy regions) and spatial complexity in the blocks. Specifically, the techniques of "minterm uniformalization" and "minterm quantization and thresholding" are presented as methods of discarding perceptually insignificant information from a minimized representation of an image and use data readily available from minimization without the calculation of complicated measures. Experimentally, results comparable to JPEG and better than existing binary techniques can be expected. Fast algorithms may be used, no multiplications are required, and decompression is performed without an inverse transform. Therefore, an emphasis is placed on the use of these algorithms for low-complexity or very high-speed hardware implementations for communications, for distributed and parallel sensor and computing applications, as well as for database storage.

关键词： image coding Noise reduction Minimization methods Educational institutions image databases image storage Transform coding Boolean functions Quantization Hardware

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Iso-splatting: a point-based alternative to isosurface visualization

Iso-splatting: a point-based alternative to isosurface visua...

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Pacific Conference on Computer Graphics and Applications

作者： C.S. Co B. Hamann K.I. Joy Center for Image Processing and Integrated Computing (CIPIC) Department of Computer Science University of California USA

We present a new approach to isosurface visualization that we call "iso-splatting." We use point primitives for representing and rendering isosurfaces. The method consists of two steps. In the first step, point samples are generated throughout the volumetric domain of a scalar function. In the second step, these points are projected onto the isosurface of interest. We render the resulting point set using a surface splatting algorithm. The method can be extended to out-of-core or parallel environments. Our results show that this method can offer much greater time and space efficiency when compared with standard triangle-based methods, thereby supporting higher levels of interactivity. Parts of the algorithm can be accelerated using graphics hardware. One key advantage of this approach is that, since extraction computations are divided into two smaller phases, work can be distributed to exploit all available resources.

关键词： Isosurfaces Visualization Rendering (computer graphics) Computational geometry Fuels image processing Computer science Acceleration Graphics Hardware

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AVHRR rectification using orbital navigation and image matching

AVHRR rectification using orbital navigation and image match...

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image and Signal processing for Remote Sensing VII

作者： Marçal, André R.S. Borges, Janete Faculdade de Ciências Universidade do Porto Departamento de Matematica Aplicada Rua do Campo Alegre 687 4169-007 Porto Portugal

Polar orbital satellites with low spatial resolution sensors, such as the AVHRR, provide global coverage with a short repetition period. The data is directly transmitted to ground stations, and can be distributed immediately after data acquisition. Near real time applications can be implemented if the adequate processing tools are available. One task usually needed is the geometric correction of image data. Automatic methods, based on satellite orbital parameters, can in some cases provide satisfactory results. However, the identification of Ground Control Points (GCPs) is generally required in order to achieve registration errors below the pixel size. A fully automatic method for the geometric registration of AVHRR data is proposed here. The method comprises four stages: (i) an initial image transformation based on orbital parameters, (ii) image segmentation of this image into 3 main classes (land, water, cloud) and 9 additional classes of mixed water and land at various levels, (iii) automatic GCP collection by image matching, (iv) final image production combining both orbital and GCP information. The method was tested on ten images of the Iberian Peninsula, and proved effective in accurately geo-referencing sub-sections of an AVHRR scene of medium dimension in a few minutes.

关键词： Radiometers

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Efficient tiling for an ODE discrete integration program: redundant tasks instead of trapezoidal shaped-tiles

Efficient tiling for an ODE discrete integration program: re...

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International Symposium on parallel and distributed processing (IPDPS)

作者： F. Rastello T. Dauxois STMicroelectronics Grenoble France Ecole Normale Superieur de Lyon Laboratoire de physique Italie France

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Efficient second-order adaptation for large vocabulary distributed speech recognition

Efficient second-order adaptation for large vocabulary distr...

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International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： Robert W. Morris Michael E. Deisher Center for Signal & Image Processing Georgia Institute of Technology Atlanta GA USA Intel Corporation Hillsboro OR USA

This paper describes practical implementation details for a second-order approximation to the parallel model combination (PMC) algorithm with application to large vocabulary distributed speech recognition. The proposed method is capable of simultaneously adapting to noise and channel changes. A more accurate method for computing the derivatives based on numeric integration PMC is introduced. The proposed second-order adaptation algorithm requires only twice the memory and computation of standard Jacobian Adaptation (JA). This represents a 382-fold reduction in memory and a 29-fold reduction in computation. Moreover, the proposed algorithm produces models that are much closer to the PMC-derived models than standard JA.

关键词： Production facilities Hidden Markov models Approximation methods Servers Noise Adaptation model Lead

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