Signal processingalgorithms and architectures can use dynamic reconfiguration to exploit variations in signal statistics with the objectives of improved performance and reduced power consumption. Parameters provide a...
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ISBN:
(纸本)0780370414
Signal processingalgorithms and architectures can use dynamic reconfiguration to exploit variations in signal statistics with the objectives of improved performance and reduced power consumption. Parameters provide a simple and formal way to characterize incremental changes to a computation and its computing mechanism. This paper examines five parameterized computations which are typically implemented in hardware for a wireless multimedia terminal: 1) motion estimation, 2) discrete cosine transform, 3) Lempel-Ziv lossless compression, 4) 3D graphics light rendering and 5) viterbi decoding, Each computation is examined for the capability of dynamically adapting the algorithm and architecture parameters to variations in their respective input signals. Dynamically reconfigurable low-power implementations of each computation are currently underway.
We present a new multimodal system that combines stereoscopic and audio-based source localization to track the position of a flying bat. Also presented are novel algorithms for audio source localization. The bat was a...
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ISBN:
(纸本)0780370414
We present a new multimodal system that combines stereoscopic and audio-based source localization to track the position of a flying bat. Also presented are novel algorithms for audio source localization. The bat was allowed to fly in an anechoic room and monitored by two high-speed video cameras. The vocalizations of the bat were simultaneously recorded from six microphones. The data was then processed offline to localize the source and reconstruct the trajectory of the bat. We compare the performance of the localization algorithm with the position data obtained from stereoscopic pictures of the bat. The results confirm that the stereoscopic analysis and the audio localization are in good agreement. This system opens up new possibilities for performing multimodal research and developing more tightly integrated algorithms.
We present wavelet based video compression algorithms. The motion estimation and compensation, which is an essential part in the compression, is based on segment movements. The proposed based codec sequentially employ...
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ISBN:
(纸本)0780370414
We present wavelet based video compression algorithms. The motion estimation and compensation, which is an essential part in the compression, is based on segment movements. The proposed based codec sequentially employs the following steps: We first divide each frame in the sequence into blocks resulted from the block matching algorithm. The, we appply Hough transform, in order to group it into segments the blocks that have similar motion parameters. We estimate the motion parameters for each segment using several motion models and least-squares algorithm and apply motion compensation upon the frames in each group. In the wavelet domain an optimal vector bit allocation is being used to distribute the bit budget among consecutive frames. The manipulated frames in each group are quantized and coded using techniques from still image compression. The residual error of the compression is reduced by applying error correction in the wavelet domain to enhance the quality of the reconstructed sequence.
Arizona State University (ASU) has developed an On-line DSP laboratory that is based on an object-oriented Java tool called Java Digital Signal processing (J-DSP). J-DSP is currently being used in a senior-level DSP c...
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ISBN:
(纸本)0780370414
Arizona State University (ASU) has developed an On-line DSP laboratory that is based on an object-oriented Java tool called Java Digital Signal processing (J-DSP). J-DSP is currently being used in a senior-level DSP course at ASU. J-DSP has a rich suite of signal processing functions that facilitate interactive on-line simulations of modern statistical signal and spectral analysis algorithms, filter design tools, QMF banks, and speech analysis. In this paper, we present a series of significant functionality extensions of J-DSP enabling on-line laboratories in the systems-related areas of Communications, imageprocessing, and Controls. The extensions in communications are presented in some detail. In addition to these important functionality extensions, we present enhancements in the infrastructure of J-DSP that provide embedded scripting capabilities. Scripts enable easy creation and seamless integration of interactive animations in DSP web content. The latter is very important for instructors creating their own DSP-related web courses as it provides for user-friendly development of interactive visualization modules through the J-DSP applets.
We propose finite-length multi-input multi-output adaptive equalization methods for "smart" antenna arrays using the statistical theory of canonical correlations. We show that the proposed methods are relate...
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ISBN:
(纸本)0780370414
We propose finite-length multi-input multi-output adaptive equalization methods for "smart" antenna arrays using the statistical theory of canonical correlations. We show that the proposed methods are related to maximum likelihood reduced-rank channel and noise estimation algorithms in unknown spatially correlated noise, and to several recently proposed adaptive equalization schemes.
Recent works have shown that GenLOT coding is a very effective technique for compressing seismic data. The role of a transform in a coder is to concentrate information and reduce statistical redundancy. When used with...
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ISBN:
(纸本)0780370414
Recent works have shown that GenLOT coding is a very effective technique for compressing seismic data. The role of a transform in a coder is to concentrate information and reduce statistical redundancy. When used with embedded zerotree coding, GenLOTs often provide superior performance to traditional block oriented algorithms or to wavelets. In this work we investigate the use of Generalized Unequal Length Lapped Orthogonal Transforms (GULLOT). Their shorter bases for high-frequency components are suitable for reducing ringing artifacts in images. While GULLOTs yield comparable performance to GenLOTs on smooth seismic signals like stacked sections, they achieve improved performance on less smooth signals such as shot gathers.
The paper proposes a performance evaluation and comparison of recent ITU-T and ETSI voice activity detection algorithms. The comparison was made using both objective and psychoacoustic parameters, so as to have reliab...
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ISBN:
(纸本)0780370414
The paper proposes a performance evaluation and comparison of recent ITU-T and ETSI voice activity detection algorithms. The comparison was made using both objective and psychoacoustic parameters, so as to have reliable judgements that were close to subjective ones. A highly varied speech database was also set up to evaluate the extent to which VADs depend on language, the signal to noise ratio, or the power level.
The traditional imageprocessing techniques require a lot of computational effort due to data on each pixel are computed in a sequential way and the path of information is an A/D converter. The delay accumulation crea...
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ISBN:
(纸本)0819439835
The traditional imageprocessing techniques require a lot of computational effort due to data on each pixel are computed in a sequential way and the path of information is an A/D converter. The delay accumulation create in this process is unacceptable in real time imageprocessing because of the high information flow managed in the usual vision tasks (e.g. automatic industrial inspection, vision problems in robotics, pattern analysis, etc.). Thus, the use of a massive parallel architecture working with analog signals avoids the previous problems. This is just the basis idea of Cellular Neural Network (CNN's): an array of analogic dynamic processors which cells interact directly within a finite local neighborhood. The local CNN connectivity allow its realization as VLSI chips that can operate at a very high speed and complexity. Nowadays CNN architectures implemented as VLSI chips shows the aptitude of extremely high speed compared with traditional digital imageprocessing tools. The proliferation of more and more sophisticated CNN architectures, and the increasing effort to implant practical system based in CNN chips, make important the development of analog algorithm to perform complex imageprocessing tasks dedicated to many different fields, i.e. industrial applications, robotic systems and pattern recognition. The objective of this work is to generate a learning machine capable of find solutions for complex imageprocessing task by CNN's. First a general machine for automatic analog algorithm design independent of the problem to solve is created, this is accomplished through an evolutionary strategy that is an extension of genetic programming. Second, this work introduces a suite of sub-mechanisms that increase the power of genetic programming and contribute to reduce the enormous space search for producing a plentiful search. Some concepts in this section are related with AI theory, in such a way that in this work we are in the intersection field of AI and Imag
In this paper a scheme for efficient system partitioning of computation in wireless sensor networks is presented. Local computation of the sensor data in wireless networks can be highly energy-efficient, because redun...
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ISBN:
(纸本)0780370414
In this paper a scheme for efficient system partitioning of computation in wireless sensor networks is presented. Local computation of the sensor data in wireless networks can be highly energy-efficient, because redundant communication costs can be reduced. It is important to develop energy-efficient signal processingalgorithms to be run at the sensor nodes. This paper presents a technique to optimize system energy by parallelizing computation through the network and by exploiting underlying hooks for power management. By parallelizing computation, the voltage supply level and clock frequency of the nodes can be lowered, which reduces energy dissipation. A 60% energy reduction for a sensor application of source localization is demonstrated. The results are generalized for finding optimal voltage and frequency operating points that lead to minimum system energy dissipation.
DSPs with dual memory banks offer high memory bandwidth, which is required for high-performance applications. However, such DSP architectures pose problems for C compilers, which are mostly not capable of partitioning...
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ISBN:
(纸本)0780370414
DSPs with dual memory banks offer high memory bandwidth, which is required for high-performance applications. However, such DSP architectures pose problems for C compilers, which are mostly not capable of partitioning program variables between memory banks. As a consequence, time-consuming assembly programming is required for an efficient coding of time-critical algorithms. This paper presents a new technique for automatic variable partitioning between memory banks in compilers, which leads to a higher utilization of available memory bandwidth in the generated machine code. We present experimental results obtained by integrating the proposed technique into an existing C compiler for the AMS Gepard, an industrial DSP core.
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