Hybrid Filter Banks (HFB) are the suitable candidate for implementing wide-band, high-frequency A/D parallel converters. This paper proposes a modified HFB configuration called two-stage structure to overcome the alia...
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ISBN:
(纸本)0780393333
Hybrid Filter Banks (HFB) are the suitable candidate for implementing wide-band, high-frequency A/D parallel converters. This paper proposes a modified HFB configuration called two-stage structure to overcome the aliasing constraints. This structure yields much better performance in terms of aliasing, or equally a higher possible resolution than the original one. Moreover, this two-stage structure can provide the performance of the original one with approximately only half the number of coefficients in the FIR Synthesis filters. Results will be shown in the realistic case when the analog analysis filters are easy-to-implement RLC (or RC) circuits.
This paper presents the design of a new wavelet-based encoder suitable for fast and low-power image and video compression. The proposed circuit is based on a modified version of the No List SPIHT algorithm. When reali...
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ISBN:
(纸本)0780393333
This paper presents the design of a new wavelet-based encoder suitable for fast and low-power image and video compression. The proposed circuit is based on a modified version of the No List SPIHT algorithm. When realized using a XILINX Virtex XC2V1000 device, the new encoder requires only 3.4ms to perform lossless image compression on a 128x128 16-bit discrete wavelet transformed image. It uses 392 slices, similar to 15KB of RAM memory and dissipates just 8.2mW/MHz.
Although a number of diverse edge detection techniques can be found in many image processing publications, there is no single detection method that performs well in every possible image context. Information that could...
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ISBN:
(纸本)0780393333
Although a number of diverse edge detection techniques can be found in many image processing publications, there is no single detection method that performs well in every possible image context. Information that could be missed by one detector may be captured by another. The purpose of this paper is to describe a new framework which allows us to quantitatively combine the methods of different edge detection operators in order to yield improved results for edge detection in an image. The so called Receiver Operating Characteristics (ROC) analysis is employed in a novel fashion to form an optimum edge map that matches the outcomes of a preselected set of edge detectors. The results of applying the above ROC analysis technique are demonstrated and compared with individual edge detection methods.
Future terminals for CDMA will have to employ multiuser detection to implement high data rate modes such as HSDPA in the UTRA/3GPP standard. Therefore efficient and flexible detection algorithms are needed. In [1] we ...
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ISBN:
(纸本)0780393333
Future terminals for CDMA will have to employ multiuser detection to implement high data rate modes such as HSDPA in the UTRA/3GPP standard. Therefore efficient and flexible detection algorithms are needed. In [1] we have already shown an approach of such an equalizer for single user detection. The principle algorithm of this equalizer has now been extended to a multiuser detector, which can make use of the same Cordic based platform as the original equalizer. The paper shows that our approach has got a significant performance increase in comparison to a standard Rake based equalizer, whereas the computational complexity remains roughly the same.
The problem of source separation of instantaneous mixtures has been addressed thoroughly in literature in the past. The assumption of statistical independence between the source signals, led to the introduction of Ind...
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ISBN:
(纸本)0780393333
The problem of source separation of instantaneous mixtures has been addressed thoroughly in literature in the past. The assumption of statistical independence between the source signals, led to the introduction of Independent Component Analysis (ICA). A number of methods, based on the ICA framework, can identify nonGaussian sources in instantaneous mixtures with robust convergence and performance. However, in several biomedical applications, there is a need to identify and separate signals that, apart from being nonGaussian, are not symmetric. In this article, the authors present a method for blind identification and separation of skewed (non-symmetric) signals in a linear instantaneous mixture.
In this paper, a cost-effective implementation of a programmable filterbank front-end for speech recognition is presented. The objective has been to design a real-time bandpass filtering system with a filterbank of 16...
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ISBN:
(纸本)0780393333
In this paper, a cost-effective implementation of a programmable filterbank front-end for speech recognition is presented. The objective has been to design a real-time bandpass filtering system with a filterbank of 16 filters, with analog audio input and analog output. The output consists of 16 analog signals, which are the envelopes of the filter outputs of the audio signal. These analog signals are then led to an analog neural computer, which performs the feature-based recognition task. One of the main objectives has been to allow the user to easily change the filter specifications without affecting the remaining system, thus a software implementation of the filterbank was preferred. In addition, the neural computer requires analog input. Therefore, we implemented the filterbank on a PC, with the input A/D and the output D/A performed by the PC stereo soundcard. Since multiple analog outputs are necessary for the neural computer (one for each filter), it then follows that the soundcard output should contain the multiplexed 16 filter outputs, while a hardware module is needed for demultiplexing the soundcard output into the final 16 analog signals.
In this paper we present a novel method for gesture video decomposition based on the depicted content. From the initial content the key-frames are extracted and the neighboring frames are assigned to key-frames of sim...
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ISBN:
(纸本)0780393333
In this paper we present a novel method for gesture video decomposition based on the depicted content. From the initial content the key-frames are extracted and the neighboring frames are assigned to key-frames of similar content. The resulting frame groups are decomposed to binary trees, based on the energy of the depicted gestures. In case of reduced bandwidth we keep the original timeline but we send only a dynamically adapted video summary. The respective frames are obtained by moving appropriately across the hierarchy layers of the constructed tree. The hierarchically structured video can be used for purposes such as efficient video browsing and transmission of dynamically generated summaries over low bandwidth networks, for communication or human-computer interface applications.
The improving resolutions of new video appliances continuously increase the throughput requirements of video codecs and complicate the challenges encountered during their cost-efficient design. The energy limitations ...
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ISBN:
(纸本)0780393333
The improving resolutions of new video appliances continuously increase the throughput requirements of video codecs and complicate the challenges encountered during their cost-efficient design. The energy limitations of mobile appliances create the demand for low-power implementations. We propose a custom high-performance MPEG-4 video encoder. The fully dedicated video pipeline is realized using a systematic design approach and exploits the inherent functional parallelism of the compression algorithm. Memory optimizations and algorithmic optimizations combined at the high-level and their effect on the power-efficiency is demonstrated. The resulting MPEG-4 video encoder contains a tailored memory hierarchy;uses burst oriented accesses to external memory and supports real-time processing of 30 4CIF frames per second while only consuming 71 mW in a 180 mn, 1.62V UMC technology.
As the increasing size of private or online electronic text collections reaches several terabytes, finding relevant information has become a real challenge for modern computerized systems. The low classification or th...
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ISBN:
(纸本)0780393333
As the increasing size of private or online electronic text collections reaches several terabytes, finding relevant information has become a real challenge for modern computerized systems. The low classification or the data stored in repositories exempted from quality control justifies the need for approximate matching methods maintaining the efficiency or the retrieval and accuracy of the results. Moreover, because the average bandwidth or the main memory is crucial for system performance, development of digital VLSI (Very Large Scale Integration) architectures for low-level and very high throughput data processing has been a main issue in this work. Thus this paper presents the hardware realization of a text search engine using bit-parallelism and a fast serial processing of the database information. It describes the internal architecture of an associative processor which was efficiently implemented and tested on an FPGA (Field Programmable Gate Array) platform, acting yet as an external hardware accelerator for standard PC solutions.
In this paper we present the hardware and software system architecture for a personal digital video player and recorder using a media processor and an MPEG-2 video codec.
ISBN:
(纸本)0780364880
In this paper we present the hardware and software system architecture for a personal digital video player and recorder using a media processor and an MPEG-2 video codec.
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