We propose efficient load balancing methods for two computational problems namely ray tracing and bottom-up binary tree computing in a distributed environment. In the context of ray tracing, we propose a variant of a ...
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We propose efficient load balancing methods for two computational problems namely ray tracing and bottom-up binary tree computing in a distributed environment. In the context of ray tracing, we propose a variant of a static load balancing technique presented in [15] where the sampling is based on partitioning the object space. Our approach partitions the image instead and uses an efficient scheduling technique for load balancing. Computations carried out on a binary tree arise naturally in imageprocessing and network optimization problems. Many of these problems are solved efficiently in parallel by the popular tree contraction technique [1]. In this paper, we explore the tree-contraction technique in a distributed setting using the grain packing method [9]. Implementations of our algorithms on a cluster of workstations using parallel Virtual Machine (PVM) [6] demonstrate near-perfect load balancing.
Improving the computation efficiency is a key issue in imageprocessing, especially in edge detection, because edge detection is very computationally intensive. With the development of real-time application of image p...
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ISBN:
(纸本)0769515126
Improving the computation efficiency is a key issue in imageprocessing, especially in edge detection, because edge detection is very computationally intensive. With the development of real-time application of imageprocessing, fast processing response is becoming more critical. In this paper, a technique for distributedimageprocessing on Spiral Architecture is proposed, which provides a platform for speeding up imageprocessing based on clusters.
In order to reduce the real-time processing gap of distributed algorithms on smart camera networks, we have evaluated a parallelprocessing method which exploits the processing capabilities of free cameras as auxiliar...
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ISBN:
(纸本)9781450347860
In order to reduce the real-time processing gap of distributed algorithms on smart camera networks, we have evaluated a parallelprocessing method which exploits the processing capabilities of free cameras as auxiliary for busy ones. The communication infrastructure or camera processing capabilities are not included in the traditional evaluation methods like datasets or even virtual reality tools, so they are not suitable to analyze the complexity of distributed algorithms. For this purpose, we have developed a modular framework based on OMNET++ simulation environment named CAM-DIST, in which the velocity model of soccer players are emulated. Simulation results show that parallelprocessing improves overall efficiency, but could have side effects on individual camera estimations;so choosing optimal sharing value and destinations will enhance the performance.
Visual media processing is becoming increasingly important because of the wide variety of image and video based applications. Block rotation is an important operation in different image/video processing tasks such as ...
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ISBN:
(纸本)0819425885
Visual media processing is becoming increasingly important because of the wide variety of image and video based applications. Block rotation is an important operation in different image/video processing tasks such as graphics, fractal processing, pattern matching and image registration. Remote sensing, medical imaging, computer vision, computer graphics, and video coding are typical applications of digital image rotation. However, a hardware implementation of the block rotation algorithm has not been realized and software implementation is slow. Hence, they are not suitable for real-time execution. In this paper, we propose a novel method for block rotation, which is fast and suitable for hardware implementation. The algorithm employs area based interpolation. Experimental results have shown the performance enhancement compared to classical interpolation algorithms at a similar level of complexity.
In this article, we present a parallelimageprocessing system based on the concept of reactive agents. This means that, in our system, each agent has a very simple behavior which allows it to take a decision (find ou...
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ISBN:
(纸本)0819429074
In this article, we present a parallelimageprocessing system based on the concept of reactive agents. This means that, in our system, each agent has a very simple behavior which allows it to take a decision (find out an edge, a region,...) according to its position in the image and to the information enclosed in it. Our system lies in the oRis language, which allows to describe very finely and simply the agents' behaviors. In fact, oRis is an interpreted and dynamic multiagent language. First of all, oRis is an object language with the use of classes regrouping attributes and methods. The syntax is close to the CSS language and includes notions of multiple inheritance, oRis is also an agent language: every object with a method 'main()' becomes an agent. This method is cyclically executed by the system scheduler and corresponds to the agent behavior. We also present an application made with oRis. This application allows to detect concentric striae located on different natural "objects" (age-rings of tree, fish otolith growth rings, striae of some minerals,...). The stopping of the multiagent system is implemented through a technique issued from immunology: the apoptosis.
distributed and parallel computing techniques allow fast imageprocessing, namely when these techniques are applied at the low and the medium level of a vision system. In this paper, a collective and distributed metho...
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distributed and parallel computing techniques allow fast imageprocessing, namely when these techniques are applied at the low and the medium level of a vision system. In this paper, a collective and distributed method for image segmentation is introduced and evaluated. The method is modeled as a multi-agent system, where the agents aim to collectively produce a region-based segmentation. Each agent starts searching for an acceptable region seed by randomly jumping within the image. Next, it performs a region growing around its position. Thus, several agents find themselves within the same homogeneous region and are organized in a graph where two agents are connected if they are within the same region. So, a unifying of the labels in a same region is collaboratively performed by the agents themselves. The proposed method was experimented on real range images from the ABW dataset and the Object Segmentation Database (OSD) one, and the obtained results were compared to those of some well-referenced methods from the literature. The evaluation results show that the proposed method provides fast and accurate image segmentation, allowing it to be deployed for real-time vision systems.
The growth of the Web has resulted in the Web-based sharing of distributed geospatial data and computational resources. The Geospatial processing Web (GeoPW) described here is a set of services that provide a wide arr...
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The growth of the Web has resulted in the Web-based sharing of distributed geospatial data and computational resources. The Geospatial processing Web (GeoPW) described here is a set of services that provide a wide array of geo-processing utilities over the Web and make geo-processing functionalities easily accessible to users. High-performance remote sensing imageprocessing is an important component of the GeoPW. The design and implementation of high-performance imageprocessing are, at present, an actively pursued research topic. Researchers have proposed various parallel strategies for single imageprocessing algorithm, based on a computer science approach to parallelprocessing. This article proposes a multi-granularity parallel model for various remote sensing imageprocessing algorithms. This model has four hierarchical interfaces that are labeled the Region of Interest oriented (ROI-oriented), Decompose/Merge, Hierarchical Task Chain and Dynamic Task interfaces or sub-models. In addition, interfaces, definitions, parallel task scheduling and fault-tolerance mechanisms are described in detail. Based on the model and methods, we propose an open-source online platform named OpenRS-Cloud. A number of parallel algorithms were uniformly and efficiently developed, thus certifying the validity of the multi-granularity parallel model for unified remote sensing imageprocessing web services.
image encryption is an efficient technique to protect image content from unauthorized parties. In this paper a parallelimage encryption method based on bitplane decomposition is proposed. The original grayscale image...
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image encryption is an efficient technique to protect image content from unauthorized parties. In this paper a parallelimage encryption method based on bitplane decomposition is proposed. The original grayscale image is converted to a set of binary images by local binary pattern (LBP) technique and bitplane decomposition (BPD) methods. Then, permutation and substitution steps are performed by genetic algorithm (GA) using crossover and mutation operations. Finally, these scrambled bitplanes are combined together to obtain encrypted image. Instead of random population selection in GA, a deterministic method with security keys is utilized to improve security level. The proposed encryption method has parallelprocessing capability for multiple bitplanes encryption. This distributed GA with multiple populations increases encryption speed and makes it suitable for real-time applications. Simulations and security analysis are done to demonstrate efficiency of our algorithm.
Scientific datasets of large volumes generated by next-generation computational sciences need to be transferred and processed for remote visualization and distributed collaboration among a geographically dispersed tea...
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Scientific datasets of large volumes generated by next-generation computational sciences need to be transferred and processed for remote visualization and distributed collaboration among a geographically dispersed team of scientists. parallel visualization using high-performance computing facilities is a typical approach to processing such increasingly large datasets. We propose an optimized image compositing scheme with linear pipeline and adaptive transport to support efficient image delivery to a remote client. The proposed scheme arranges an arbitrary number of parallel processors within a cluster in a linear order and divides the image into a carefully selected number of segments, which flow through the linear incluster pipeline and wide-area networks to the remote client consecutively. We analytically determine the segment size that minimizes the final image display time and derive the conditions where the proposed image compositing and delivery scheme outperforms the traditional schemes including the binary swap algorithm. In order to match the transport throughput for image delivery over wide-area networks to the pipelining rate for image compositing within the cluster, we design a class of transport protocols using stochastic approximation methods that are able to stabilize the data flow at a target rate. The experimental results from remote visualization of large-scale scientific datasets justify the correctness of our theoretical analysis and illustrate the superior performances of the proposed method. (C) 2008 Elsevier Inc. All rights reserved.
Contract-Linda is a novel programming architecture for heterogeneous parallel machines particularly suited to imageprocessing. Previous research has concentrated on static and pre-determined scheduling of computation...
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ISBN:
(纸本)0819425885
Contract-Linda is a novel programming architecture for heterogeneous parallel machines particularly suited to imageprocessing. Previous research has concentrated on static and pre-determined scheduling of computation and on fine grain parallelism. Pre-determined scheduling is satisfactory in cases where the computational process is fully deterministic. However with many image interpretation schemes the flow of control and the nature of the computational procedures can only be determined at run-time. In this paper we describe a programming paradigm for coarse grain and task level parallelism. Task management is based on the Contract Net protocol and utilises the Linda. Coordination Language to provide run-time scheduling. This paradigm accommodates a closely coupled network of heterogeneous processing modules which differ greatly in computational capability;modules based on neural networks, semantic networks, vector and scalar processors are accommodated. Contract;Linda allo-cvs specialised heterogeneous machines to be exploited using a straightforward generic programming model. It does this by providing an internal task management mechanism which ensures that the heterogeneous processing elements are used by the tasks most suited to them and exploits dynamic parallelism within the problem as it is solved. By separating the task of describing the problem from that of describing how the work is carried out on the machine (and providing a solution for this problem) we allow applications to be quickly developed which can effectively utilise specialised machines without the need for specialised programming. We report an experiment to re-implement a cell image interpretation system using Contract-Linda.
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