The Discrete wavelet Transform (DWT) is a signalprocessing technique popularised by its results in data compression. Considerable work has been done in designing novel architectures to perform the DWT, including a sy...
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The Discrete wavelet Transform (DWT) is a signalprocessing technique popularised by its results in data compression. Considerable work has been done in designing novel architectures to perform the DWT, including a systolic architecture designed by the authors, but little attention has been given to the inverse DWT which is needed in applications such as data compression for signal reconstruction. Despite the fact that the inverse DWT is computationally the reverse of the DWT, the hardware design for the architecture is not simply mirrored. Existing designs expect the architecture for the inverse DWT to be a simple follow-on step from the DWT design, however this is not the case. We present one such problem here, showing the FIFO buffering required on the input of the inverse architecture. We show how the size of this buffer can be calculated and compare it to a fixed data array implementation. This work is based on our systolic array design and is an integral part of the inverse DWT design we are working on for image and video compression.
The variety of signal sources and the wide range of analytical techniques pose a serious problem in the integrated setup development for biomedical signalprocessing. In this paper we present an integrated, personal c...
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The variety of signal sources and the wide range of analytical techniques pose a serious problem in the integrated setup development for biomedical signalprocessing. In this paper we present an integrated, personal computer based setup useful in a variety of biomedical signalprocessingapplications. We also present interesting case studies from VEP, IVS analysis. At the heart of the setup is a PC-AT486 with analog-to-digital converter (12 bits, 100 KSPS), serial modem and powerful, interactive digital signalprocessing (DSP) software FFT Lysis. The configuration is interfaced with the NICOLET COMPACT FOUR VEP recorder, and spike-train pre-amplifier. The DSP software on the PC-AT consists of biomedical signalprocessing modules for digital filtering, template matching FFT analysis, wavelet analysis, basic imageprocessing and pattern synthesis. In addition to these the software consists of powerful statistical classification programs for principal component analysis (PCA).
The paper presents new approaches in the field of motion-compensated spatio-temporal filters applied to digital image sequences. In time-varying imagery, the temporal correlation information of pixel intensities is fo...
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The paper presents new approaches in the field of motion-compensated spatio-temporal filters applied to digital image sequences. In time-varying imagery, the temporal correlation information of pixel intensities is folded by motions which may originate from both camera and object displacements. Motion-compensated filters are defined as temporal filters applied along assumed motion trajectories. As a matter of fact, the paper deals with three-dimensional spatio-temporal filters and aims at generalizing the motion-compensated temporal filtering process as the product of two distinct operators. The first operator depends only on the estimated motion parameters derived from both motion-based image segmentations and parametric affine modelings of regions in motion. The second operator analyzes only the correlations of image-by-image intensities measured along the assumed motion trajectories. Multiresolution filters or wavelets may be consequently applied along the motion trajectories to produce optimum and adaptive resulting procedures for purposes like spatio-temporal prediction, interpolation and smoothing. In the paper, applications are provided to cover the field of image sequence coding and interpolation.
California Polytechnic State University, USA, completed an assessment of the potential of using a video imageprocessing (VIP) system for traffic surveillance and detection on California freeways. The first phase of t...
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California Polytechnic State University, USA, completed an assessment of the potential of using a video imageprocessing (VIP) system for traffic surveillance and detection on California freeways. The first phase of the project, sponsored by the California Department of Transportation, was completed in 1991. Eight turnkey and prototype systems were identified and tested under laboratory conditions. The results showed, that while no system tested was ready for deployment at that time, several systems warranted further testing under more realistic conditions. The second phase of the project began in June 1992 and was completed recently. Four VIP systems were chosen for extended field testing to measure accuracy in traffic counts and speeds, classification, reliability, cost, ease of set-up and operation, image quality, failure rate, and ease of recovery. These variables were assessed quantitatively and qualitatively under specific conditions that included variations of lighting, approaching and departing traffic, camera angle, weather, vibration, and presence of signal noise. This paper presents the Phase ii field test results and recommendations for standardizing imageprocessing systems with a view toward eventual statewide implementation for traffic detection.
The topics included are mathematical developments;transient detection in biological systems;frames and overcomplete representations;image coding;wavelet design and construction;receiver design and demodulation;Gabor t...
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ISBN:
(纸本)0819416274
The topics included are mathematical developments;transient detection in biological systems;frames and overcomplete representations;image coding;wavelet design and construction;receiver design and demodulation;Gabor transforms;high speed processing;detecting chaotic signals and denoising;image compression;multiscale representations;medical imaging;segmentation and classification;signal filtering;feature extraction;and motion estimation.
wavelet analysis is currently being investigated as an image enhancement tool for use in mammography. Although this approach to imageprocessing appears to have great promise, there remain major uncertainties regardin...
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ISBN:
(纸本)0819416274;9780819416278
wavelet analysis is currently being investigated as an image enhancement tool for use in mammography. Although this approach to imageprocessing appears to have great promise, there remain major uncertainties regarding an optimal form of wavelet based algorithms. It is, therefore, desirable to have a quantitative method for evaluating a wavelet based imageprocessing algorithm. Optimization of algorithms prior to evaluation using standard Receiver Operating Characteristic method is made possible. A mathematical method has been developed where the input signal is a gaussian with added random noise. An enhancement factor (EF) is obtained from input and output signal-to-noise ratios, SNRi and SNRo, (EF = SNRo/SNRi). The development and testing of this method is described, and a practical application in given showing the major features of a wavelet based imageprocessing algorithm based on the Frazier-Jawerth transform.
In this paper, the performance of filters implied in the discrete wavelet transform approach is compared with a set of filters of common application in imageprocessing. A multidimensional multirate codec is designed ...
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ISBN:
(纸本)0819416274;9780819416278
In this paper, the performance of filters implied in the discrete wavelet transform approach is compared with a set of filters of common application in imageprocessing. A multidimensional multirate codec is designed in which the best subband decomposition and coding is jointly obtained by minimization of a rate-distortion criterion. We also introduce the idea of directional sensitivity based on the initial sampling lattice. This allows the codec to adapt better to the spectral content of the signal. Finally, taking as a starting point the continuous wavelet transform, we propose a discrete multiresolution analysis that would lead to new discrete transforms of special interest when analyzing discrete scalings and shiftings: the completely discrete wavelet transform.
We consider the effect of the quantization noise introduced by coding at subbands. We demonstrate that significant noise reduction is achieved by using wavelet frames and their associated filter banks in a subband sig...
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ISBN:
(纸本)0819416274;9780819416278
We consider the effect of the quantization noise introduced by coding at subbands. We demonstrate that significant noise reduction is achieved by using wavelet frames and their associated filter banks in a subband signalprocessing system.
This paper presents two multiresolution algorithms for detection and separation of mixed signals using the wavelet transform. The first algorithm allows one to design a mother wavelet and its associated wavelet grid t...
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ISBN:
(纸本)0819416274;9780819416278
This paper presents two multiresolution algorithms for detection and separation of mixed signals using the wavelet transform. The first algorithm allows one to design a mother wavelet and its associated wavelet grid that guarantees the separation of signal components if information about the expected minimum signal time and frequency separation of the individual components is known. The second algorithm expands this idea to design two mother wavelets which are then combined to achieve the required separation otherwise impossible with a single wavelet. Potential applications include many biological signals such as ECG, EKG, and retinal signals.
We have successfully compressed audio signals using wavelet packets based on a recently developed fast wavelet transform (FWT) scheme using circular convolution with an adaptive hybrid filter/basis system. This algori...
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ISBN:
(纸本)0819416274;9780819416278
We have successfully compressed audio signals using wavelet packets based on a recently developed fast wavelet transform (FWT) scheme using circular convolution with an adaptive hybrid filter/basis system. This algorithm gives perfect reconstruction of the data; edge effects are removed entirely. As a result, the quality of audio signal compression is much improved. To illustrate this, we present results from our comparison study where we compressed a test signal using these `circular wavelet packets' and wavelet packets based on the standard FWT.
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