image analysis problems, posed mathematically as variational principles or as partial differential equations, are amenable to numerical solution by relaxation algorithms that are local, iterative, and often parallel. ...
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image analysis problems, posed mathematically as variational principles or as partial differential equations, are amenable to numerical solution by relaxation algorithms that are local, iterative, and often parallel. Although they are well suited structurally for implementation on massively parallel, locally interconnected computational architectures, such distributed algorithms are seriously handi capped by an inherent inefficiency at propagating constraints between widely separated processing elements. Hence, they converge extremely slowly when confronted by the large representations of early vision. Application of multigrid methods can overcome this drawback, as we showed in previous work on 3-D surface reconstruction. In this paper, we develop multiresolution iterative algorithms for computing lightness, shape-from-shading, and optical flow, and we examine the efficiency of these algorithms using synthetic image inputs. The multigrid methodology that we describe is broadly applicable in early vision. Notably, it is an appealing strategy to use in conjunction with regularization analysis for the efficient solution of a wide range of ill-posed image analysis problems.
An image generation system by ray tracing was implemented on a distributedparallelprocessing system composed of loosely coupled multimicrocomputers. An improvement was made by extending the architecture from the sta...
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An image generation system by ray tracing was implemented on a distributedparallelprocessing system composed of loosely coupled multimicrocomputers. An improvement was made by extending the architecture from the star structure to the hierarchical tree structure. This improvement makes it possible for an animated image to be generated at high speed with shading which can represent the shape and texture of three-dimensional objects with high quality. This paper outlines the hierarchical tree-structured image generation system, discussing the parallelprocessing mechanisms of the system, such as data transfer and hierarchical load distribution schemes. Experiments were made to evaluate the performance. Problems in the tree-structured system are pointed out, and remedies are proposed (area redistribution, and area subdivision). Experiments are made to evaluate the effectiveness of these methods. Thus, it is demonstrated that the tree-structured system is useful in the image generation using ray tracing.
Theorists in Edinburgh University Physics Department are currently using two ICL distributed Array Processors (DAPs), programmed in a matrix and vector extension of FORTRAN called DAP FORTRAN, to perform a variety of ...
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Theorists in Edinburgh University Physics Department are currently using two ICL distributed Array Processors (DAPs), programmed in a matrix and vector extension of FORTRAN called DAP FORTRAN, to perform a variety of numerical simulations. However, many of the next generation of array processors, in particular the GEC Rectangular image and Data processor (GRID), will be programmed in parallel extensions of C, like GRID-extended C. In this paper software is described which translates DAP FORTRAN into GRID-extended C, as well as FORTRAN 77 into C, enabling DAP FORTRAN programs to be run on the GRID.
The distributed Array Processor is a two dimensional interconnected array of 4096 processors, each with its own associated memory. Programming techniques on the DAP are often radically different from their serial coun...
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The distributed Array Processor is a two dimensional interconnected array of 4096 processors, each with its own associated memory. Programming techniques on the DAP are often radically different from their serial counterparts and two techniques that fit well on the DAP architecture are logical manipulation and recursive doubling. Both of these techniques are used in graphics and imageprocessing applications in areas as far apart as basic line drawing, and fourier transforms. Examples will be given of the type of performance and results available from these methods.
Theorists in Edinburgh University Physics Department are currently using two ICL distributed Array Processors (DAPs), programmed in a matrix and vector extension of FORTRAN called DAP FORTRAN, to perform a variety of ...
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Theorists in Edinburgh University Physics Department are currently using two ICL distributed Array Processors (DAPs), programmed in a matrix and vector extension of FORTRAN called DAP FORTRAN, to perform a variety of numerical simulations. However, many of the next generation of array processors, in particular the GEC Rectangular image and Data processor (GRID), will be programmed in parallel extensions of C, like GRID-extended C. In this paper software is described which translates DAP FORTRAN into GRID-extended C, as well as FORTRAN 77 into C, enabling DAP FORTRAN programs to be run on the GRID.
In this paper we describe some aspects of specifying, designing and evaluating a specialized machine, Romuald, for the capture, coding, and processing of video and scanning electron microscope (SEM) pictures. First we...
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The authors have presented nine different ways to propagate a seed value into a region of a binary image. They summarize the time complexities of these methods. An additional method recursive data-dependent scan has b...
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ISBN:
(纸本)0892524707
The authors have presented nine different ways to propagate a seed value into a region of a binary image. They summarize the time complexities of these methods. An additional method recursive data-dependent scan has been added because it is commonly used in practice;there a pushdown stack is used to implement a kind of backtracking search to perform a polygon-fill propagation. For convex, thick objects the fastest approach is parallel pyramidal using (4n**2/3) processors and the best algorithm for a distributedparallel system is distributed pyramidal.
This paper presents efficient methods of parallel-pipeline Walsh-Hadamard transformation for fast coding of decomposed pictures. The decomposition of the pictures is realized by the known regular decomposition methodo...
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This paper presents efficient methods of parallel-pipeline Walsh-Hadamard transformation for fast coding of decomposed pictures. The decomposition of the pictures is realized by the known regular decomposition methodology. The regular decomposition procedure converts the picture into a tree presentation and compresses the original amount of picture-data by rejecting non-informative areas of the picture. The Walsh-Hadamard transformation is performed on the regularly-decomposed picture as an averaging or smearing process to allow transmission which is more immune to channel errors. It also makes bandwidth reduction possible because, since the image energy which is usually uniformaly distributed in spatial domain now tends to be concentrated near the origin of the transform domain, some of the low-magnitude samples may be discarded.
In recent years ″software engineering″ has emerged as a discipline of programming. It includes the conceptualization, design, implementation, testing and modification of software systems. Related issues are language...
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In recent years ″software engineering″ has emerged as a discipline of programming. It includes the conceptualization, design, implementation, testing and modification of software systems. Related issues are languages, standards, distributed and parallelprocessing, and total programming environments. The fact that more than 80 percent of system development costs were in software rather than hardware helps one appreciate the importance of any effort to understand and enhance the software production process. Many pattern recognition projects involve fairly large software efforts. It makes sense not only for researchers to make use of the latest software tools and methodologies but also to anticipate future changes.
In recent years ″software engineering″ has emerged as a discipline of programming. It includes the conceptualization, design, implementation, testing and modification of software systems. Related issues are language...
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In recent years ″software engineering″ has emerged as a discipline of programming. It includes the conceptualization, design, implementation, testing and modification of software systems. Related issues are languages, standards, distributed and parallelprocessing, and total programming environments. The fact that more than 80 percent of system development costs were in software rather than hardware helps one appreciate the importance of any effort to understand and enhance the software production process. Many pattern recognition projects involve fairly large software efforts. It makes sense not only for researchers to make use of the latest software tools and methodologies but also to anticipate future changes.
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