Reprogramming is an essential service for wireless sensor networks. Authenticating reprogramming process is important as sensors need to verify that the code image is truly from a trusted source. There are two ways to...
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In message-passing parallel applications, messages are not delivered in a strict order. In most applications, the computation results and the set of messages produced during the execution should be the same for all di...
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This paper describes several system-level interconnection strategies for a coarse-grained reconfigurable fabric designed for low-energy hardware acceleration. A small, representative sub-graph for signal and image pro...
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In the past a few years, wavelet transforms have become a hot topic of research. Discrete and continuous wavelet transforms have been widely used in signal and multimedia processing. Due to the high performance and fl...
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Bicubic interpolation is one of the standard approaches for image magnification since it can be easily computed and does not require a priori knowledge nor a complicated model. In spite of such convenience, the images...
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Bicubic interpolation is one of the standard approaches for image magnification since it can be easily computed and does not require a priori knowledge nor a complicated model. In spite of such convenience, the images enlarged by bicubic interpolation are blurry, in particular for large magnification factors. This may be explained by four constraints of bicubic interpolation. Hence, by relaxing or replacing the constraints, we propose a new magnification method, which performs better than bicubic interpolation, but retains its compactness. One of the constraints is about criterion, which we replace by a criterion requiring that all pixel values are reproduced and preferential components in input images are perfectly reconstructed. We show that, by choosing the low frequency components or edge enhancement components in the DCT basis as the preferential components, the proposed method performs better than bicubic interpolation, with the same, or even less amount of computation.
Quadtree-based terrain visualization methods have been used in a lot of applications. However, because most procedures are performed on the CPU, the rendering speed is slow. In this paper, we present a quadtree-based ...
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ISBN:
(纸本)3540472428
Quadtree-based terrain visualization methods have been used in a lot of applications. However, because most procedures are performed on the CPU, the rendering speed is slow. In this paper, we present a quadtree-based terrain visualization method working on the GPU with specially designed data structure, the error-buffer and flag-buffer named ef-buffers. In pre-processingstep, error metrics are computed in world space and the error metrics are transferred to the error-buffer. In rendering time, LOD selection and view-frustum culling are processed by evaluating the error metrics. The result is stored into the flag-buffer. To remove cracks or T-junction, the flag-buffer is refined. Then triangulation is performed using the flag-buffer. This method reduces CPU load and performs time consuming jobs such as LOD selection and view-frustum culling on the GPU. We can conclude that our method much faster than CPU-based rendering method without loss of image quality.
In this paper, we present a new technique to find the optimal neighborhood decomposition for convex structuring elements used in morphological imageprocessing on hexagonal grid. In neighborhood decomposition, a struc...
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ISBN:
(纸本)3540472428
In this paper, we present a new technique to find the optimal neighborhood decomposition for convex structuring elements used in morphological imageprocessing on hexagonal grid. In neighborhood decomposition, a structuring element is decomposed into a set of neighborhood structuring elements, each of which consists of the combination of the origin pixel and its six neighbor pixels. Generally, neighborhood decomposition reduces the amount of computation required to perform morphological operations such as dilation and erosion. Firstly, we define a convex structuring element on a hexagonal grid and formulate the necessary and sufficient condition to decompose a convex structuring element into the set of basis convex structuring elements. Secondly, decomposability of a convex structuring element into the set of primal bases is also proved. Furthermore, cost function is used to represent the amount of computation or execution time required for performing dilations on different computing environments and by different implementation methods. The decomposition condition and the cost function are applied to find the optimal neighborhood decomposition of a convex structuring element, which guarantees the minimal amount of computation for morphological operations. Example decompositions show that the decomposition results in great reduction in the amount of computation for morphological operations.
imageprocessing systems are increasingly used in safety-critical applications, and their hardening against soft errors becomes an issue. The authors propose a methodology to identify soft errors as uncritical based o...
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ISBN:
(纸本)9780769527062;076952706X
imageprocessing systems are increasingly used in safety-critical applications, and their hardening against soft errors becomes an issue. The authors propose a methodology to identify soft errors as uncritical based on their impact on the system's functionality. The authors call a soft error uncritical if its impact is provably limited to image perturbations during a very short period of time (number of cycles) and the system is guaranteed to recover thereafter. Uncritical errors do not require hardening as their effects are unperceivable for the human user of the system. The authors focus on soft errors in the motion estimation subsystem of MPEG-2 and introduce different definitions of uncritical soft errors in that subsystem. A method is proposed to automatically determine uncritical errors and provide experimental results for various parameters. The concept can be adapted to further systems and enhance existing methods
We investigate the performance improvement of a multithreaded MPEG-4 video encoder executing on a configurable, extensible, SoC multiprocessor. Architecture-level results indicate a significant reduction in the dynami...
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ISBN:
(纸本)076952365X
We investigate the performance improvement of a multithreaded MPEG-4 video encoder executing on a configurable, extensible, SoC multiprocessor. Architecture-level results indicate a significant reduction in the dynamic instruction count of the order of 83% for 16 processor contexts compared to the original single-thread implementation. We extended an open-source 32-bit RISC CPU to include hardware-based multi-processing primitives and associated support state and implemented a parametric, bus-based SoC multiprocessor as the target platform for the threaded video encoder.
This paper aims at proposing an elastically deformable surface with use of differential geometric structures. On the basis of the Theory of a Cosserat Surface, a computationally processable equation that relates the a...
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ISBN:
(纸本)0769522270
This paper aims at proposing an elastically deformable surface with use of differential geometric structures. On the basis of the Theory of a Cosserat Surface, a computationally processable equation that relates the accumulated elastic energy and the variations in the differential geometry variables (metric and curvature tensors) of the deformable surface is presented On the basis of our analysis, we propose a novel algorithm to compute more precisely, without compromising the interface's simplicity, the potential deformation energy in terms of the derivatives of the surface. With our proposal, we may maintain the finite difference scheme for computing deformations iteratively. Some simulation results are included.
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