In iterative solution procedures for problems in science and engineering, AMG methods with inexpensive computation of the hierarchy of coarse-grid operators are a good choice to solve systems of linear equations where...
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ISBN:
(纸本)9783642152900
In iterative solution procedures for problems in science and engineering, AMG methods with inexpensive computation of the hierarchy of coarse-grid operators are a good choice to solve systems of linear equations where accurate solutions of these systems are not needed. In this contribution we demonstrate that the parallel performance of tins kind of algorithm is significantly improved if they are applied in combination with the Smoothed Aggregation approach, since this reduces the number of communication events. The resulting hybrid algorithms are particularly beneficial on systems where the number of messages limits the performance.
As a massively parallel processor, the GPU is well-suited for performing 'per-pixel' operations in imageprocessing and computer vision. New developments in hardware, software, and algorithm mappings now allow...
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ISBN:
(纸本)9780819479365
As a massively parallel processor, the GPU is well-suited for performing 'per-pixel' operations in imageprocessing and computer vision. New developments in hardware, software, and algorithm mappings now allow entire vision algorithms to be performed exclusively on GPU. In this paper we present the GPU mapping of a natural image feature processing pipeline used in an image stitching application. We examine how to utilize hardware features on the GPU for efficient processing to demonstrate how GPU programming now goes beyond per-pixel mappings, and is providing speedups in image feature processing, and matching.
We propose a novel fourth order dual method for the minimization of the non-smooth semi-norm parallel to *** to(1) when in amalgamation with a new staircase reducing texture decomposition model of imageprocessing. Th...
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ISBN:
(纸本)9781424479948
We propose a novel fourth order dual method for the minimization of the non-smooth semi-norm parallel to *** to(1) when in amalgamation with a new staircase reducing texture decomposition model of imageprocessing. The proposed model incorporating this high order energy is a variant of the Chambolle Lions denoising model that additionally utilizes a negative Sobolev norm. We claim that the dual method is faster and more stable than the current gradient descent time marching algorithms often used to minimize such energies. Moreover, a proof of convergence of the proposed method, in conjunction with the new model, will be provided. Lastly, we provide guidelines on how the new energy and proposed framework can be naturally incorporated into many popular texture extraction and restoration models of imageprocessing.
Map Reduce is a key-value based programming model and an associated implementation for processing large data sets. It has been adopted in various scenarios and seems promising. However, when spatial computation is exp...
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Variable-Length Encoding (VLE) is a process of reducing input data size by replacing fixed-length data words with codewords of shorter length. As VLE is one of the main building blocks in systems for multimedia compre...
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ISBN:
(纸本)9783642141218
Variable-Length Encoding (VLE) is a process of reducing input data size by replacing fixed-length data words with codewords of shorter length. As VLE is one of the main building blocks in systems for multimedia compression, its efficient implementation is essential. The massively parallel architecture of modern general purpose graphics processing units (CPGPUs) has been successfully used for acceleration of inherently parallel compression blocks, such as image transforms and motion estimation. On the other hand, VLE is an inherently serial process due to the requirement of writing a variable number of bits for each codeword to the compressed data stream. The introduction of the atomic operations on the latest CPGPUs enables writing to the output memory locations by many threads in parallel. We present a novel data parallel algorithm for variable length encoding using atomic operations, which archives performance speedups of up to 35-50x using a CUDA-enabled GPGPU.
Graph cuts methods are at the core of many state-of-theart algorithms in computer vision due to their efficiency in computing globally optimal solutions. In this paper, we solve the maximum flow/minimum cut problem in...
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ISBN:
(纸本)9781424469840
Graph cuts methods are at the core of many state-of-theart algorithms in computer vision due to their efficiency in computing globally optimal solutions. In this paper, we solve the maximum flow/minimum cut problem in parallel by splitting the graph into multiple parts and hence, further increase the computational efficacy of graph cuts. Optimality of the solution is guaranteed by dual decomposition, or more specifically, the solutions to the subproblems are constrained to be equal on the overlap with dual variables. We demonstrate that our approach both allows (i) faster processing on multi-core computers and (ii) the capability to handle larger problems by splitting the graph across multiple computers on a distributed network. Even though our approach does not give a theoretical guarantee of speedup, an extensive empirical evaluation on several applications with many different data sets consistently shows good performance. An open source implementation of the dual decomposition method is also made publicly available.
The increasing availability of multi-core and multi-processor architectures provides new opportunities for improving the performance of many computer simulations. Markov Chain Monte Carlo (MCMC) simulations are widely...
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Many attempts have been made to optimize the median filter from the software and hardware approach. An architectural design of hardware capable of performing real-time median filtering is presented. The architecture u...
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ISBN:
(纸本)9780889868205
Many attempts have been made to optimize the median filter from the software and hardware approach. An architectural design of hardware capable of performing real-time median filtering is presented. The architecture uses the histogram approach to calculate the median, while optimizing the sliding window method to reuse all its calculations. Data is output row by row and every input pixel is processed only once. The design is independent of window size or image size, and supports adding more processing elements to support wider images. The control unit design is minimized to enable self-adjustment of plug-and-play processing elements. The architecture is implemented in VHDL and synthesized to a Virtex-2 Pro FPGA. The architecture's performance as well as operation is compared to previous work.
The processing of high resolution raster images involves high computing load. Most of the programmers and image specialists are not familiar with parallel programming. Nowadays almost all desktop computers have multip...
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ISBN:
(纸本)9781617820670
The processing of high resolution raster images involves high computing load. Most of the programmers and image specialists are not familiar with parallel programming. Nowadays almost all desktop computers have multiple core processors, so it is straightforward to use parallel programming to make efficient imageprocessing algorithms. We will show a method that is able to automatically parallelize a sequential image filter. Furthermore, we will show another method that decreases the memory consumption of raster image filters. The later one uses a virtual image, so the input image can be safely overwritten with the result image. By using these methods, beginner programmers could even use the benefits of the multicore processor based computers, turning their filters into faster and multithread-safe filters. We have carried out a basic testing of kernel based raster image filters, and we have experienced a linear, n times speed-up factor, where n is the number of CPU cores.
The paper discusses tomography reconstruction of distributed physical fields by means of fiber optical measuring systems (FOMN) [1] for parallel setup of measuring lines with a small number of scanning directions. The...
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