Fourth International Symposium on Signal Processing and Its Applications最新文献

{"title":"Access and Retrieval from Image Databases Using Image Thumbnails","authors":"H. Cohen","doi":"10.1109/ISSPA.1996.615776","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615776","url":null,"abstract":"The emerging role of thumbnail images in the selection of images for display from large image databases and via network access requires that the characteristics of thumbnails be seriously studied. We introduce a measure of effective compression Ceff(p) that is a function of the probability p that thumbnail access will be followed by the display of a full-scale image. For credible values of p, we deduce the need for the development of thumbnail-based image compression schemes, which efficiently and effectively use thumbnail data as part of the code for the fullscale image. We briefly discuss design features of thumbnailbased variants of the block-oriented coding schemes of vector quantization, fractal coding, and JPEG. 1. THUMBNAIL IMAGES Thumbnail images are now commonly used as WYSIWYG directory icons for the selection of images from directories and local databases. Notable systems for managing query of image databases, the QBIC system developed by Niblack and coworkers at IBM San Jose, [2] and the PhotoBook System developed at MIT Media Lab by Pentland et al, [3], feature arrays of small images for displaying the images most similar in content to the users query. A number of researchers, notably Picard[3], have stressed the important emerging role of very large image databases as in collections of compressed images stored on a CD ROM, or the far larger compilations available via the Internet. The needs for a user-friendly interface to these very large image albums and libraries requires the development of image compression schemes suitable and efficient for applications where the image thumbnails are more often required than full images, and full image display is invariably preceded by a data fetch of the thumbnail data. This entails that image compression schemes suitable for very large database applications should be so designed that thumbnail data is separately accessible, and that the information delivered in the thumbnail should be used with other image code for economical image synthesis or reconstruction. In this paper these considerations lead us to introduce a measure of image compression that gives an effective compression for image data accessed via thumbnails. We examine how traditional block-oriented vector quantization (VQ) and fractal coding based on Jacquin's scheme should be modified. Finally we discuss JPEG coding in this regard. 1.1 Gray-scale Thumbnails Although image thumbnails are now commonplace, a literature search failed to locate any previous formal description of thumbnails. The following general definition of a thumbnail image is proposed: An image thumbnail is produced after the partitioning of an image into rectangular (usually square) blocks of pixels, and constructing a thumbnail image comprising blocks, of single pixel-size or larger, of uniform pixel value. The blocks in the thumbnail are uniformly scaled with respect to those of the image. In the simplest case of the uniform partitioning of an image into const","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115262228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polynomial time-frequency distributions and timevarying higher-order spectra: A review of performance for non-stationary signal analysis","authors":"B. Boashash, B. Ristic","doi":"10.1109/ISSPA.1996.615126","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615126","url":null,"abstract":"A class of Polynomial time-frequency distributions has been recently proposed. It achieves the highest possible concentration in the time-frequency plane for nonlinear polynomial FM signals. Further, it allows to define time-varying higher-order spectra for nonstationary random signals. The paper presents a review of recent results and an application to multi-component signal analysis in the presence of additive and/or multiplicative noise.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123267503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On The Relationship Between The Self-similarities Of Fractal Signals And Wavelet Transforms","authors":"Bing-Fei Wu, Yu-lin Su","doi":"10.1109/ISSPA.1996.615149","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615149","url":null,"abstract":"Since many natural phenomena are occasionally defined as stochastic processes and the corresponding fractal characteristics are hidden from their correlation functions or power spectra, the topic would become very interest in signal processing. In this paper, we summarize the fractal dimensions and the relationship of the fractal in probability measure, variance, time series, time-averaging autocorrelation, ensemble-averaging autocorrelation, time-averaging power spectrum, average power spectrum and htribution functions for stationary and nonstationary processes. we also propose that the preservation of the one-dimensional selfsimilarity of a fractal signal is obtained by using the continuous wavelet transform (CWT) and the discrete wavelet transform (DWT) with the perfect reconstruction - quadrature mirror filter structure. Moreover, we extend the results to the two-dimensional case and point out the relationship of the self-similarities between the CWT and DWT of the fractal signals. A fractional Brownian motion process is provided as an example to show the results of this paper.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125579906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Video Processing With Custom Computers","authors":"N. Bergmann","doi":"10.1109/ISSPA.1996.615129","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615129","url":null,"abstract":"Custom computers use SRAM-based Field Programmable Gate Arrays as a co-processor resource in addition to the CPU. This allows algorithm developers to adapt not only the software but also the hardware of the computer on an application-by-application basis. Algorithm speedups of up to hundreds of times compared to standard software have been reported. This paper investigates the applicability of custom computing techniques for video processing applications.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126538136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robot Vision System Using Differential Image Information And Geometrical Relations Of Moving Edges","authors":"N. Harle, Min Xi","doi":"10.1109/ISSPA.1996.615105","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615105","url":null,"abstract":"For robot vision, it is important to extract features from a sequence of image frames rather than from each image individually. The high rate of image frames in a video sequence supplies a high amount of information. Extracting this information makes it necessary to introduce several processing stages which exchange data asynchronously and rhus working at different speed. Algorithms in the early processing stage have to be fast in order to work on each frame whereas algorithms in later stages which extract information on a hight:r level may be slower and more complex. For this paper, it is assumed that the camera can be moved in a controlled way. A structure of a robot vision system is presented which detects the movements of edges in a sequence of images and assigns the third dimension by interpreting the movements. It considers edges due to the static environment and the movement of the camera and edges due to moving: objects. A last stage deals with the object recognition. The whole system is supervised by a \"Vision Manager\" which controls the camera as well as the regions of interest and thus ensures that important tasks are carried out within a limited range of processing power.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130003921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low Data Rate Adaptive Transform Coding For Parametric Representation Of Speech Signals","authors":"Edward Glazebrook, A. B. Bradley","doi":"10.1109/ISSPA.1996.615158","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615158","url":null,"abstract":"This paper investigates the potential for data rate reduction through the use of a phonetic se-gnentation criteria to identify spectral regions exhibiting slowly evolving features. A two dimensional discrete cosine transform (DCT) is then applied to the encoding of the segmented regions represented in this case by line spectral pair (LSP) filter parameters. This adaptive block transform code (ABTC) technique has been integrated into the CELP framework to realise an average worst case reduction of 27% over the standard CELP quantiser for an equivalent average quantisation distortion of 1.3dB. Both objective and subjective performance are compared to the standard CELP quantiser.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129618219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Algorithms For Instantaneous Bandwidth Estimation","authors":"B. Ristic","doi":"10.1109/ISSPA.1996.615146","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615146","url":null,"abstract":"The instantaneous frequency of the observed signal often describes some physical phenomenon of interest. As the instantaneous frequency is interpreted as the mean frequency at a particular instant of time, it is natural to supplement its measure by the estimate of its instantaneous spread or bandwidth. Assuming a polynomial model of log-envelope of an AM-FM signal, the paper first considers the maximum likelihood (ML) estimation and Cramer-Rao bounds for instantaneous bandwidth (IB). Then two simpler algorithms for IB estimation are proposed: the log-envelope difference algorithm and the LS method.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"72 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120982550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of an Electromagnetic Environment for Performance Analysis of Radar Receivers","authors":"P. Boord, N. Martin","doi":"10.1109/ISSPA.1996.615692","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615692","url":null,"abstract":"The following paper discusses the development of target signatures for use in Hardware-in-the-loop simulations. The approach used is to develop a statistical model of the target signature using probability distribution functions of target noise. The model is then implemented in real time using Direct Digital Synthesis technology.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127239236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid Algorithms For Maximum Likelihood And Maximum A Posterior Sequence Estimation","authors":"R. Mahony, G. D. Brushe, J. Moore","doi":"10.1109/ISSPA.1996.614973","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.614973","url":null,"abstract":"This paper presents two methods of processing data generated by a hidden Markov model (HMM) such that the resulting state estimates are related to both the maximum likelihood (ML) estimates (generated by the Viterbi algorithm) and maximum a posreriori (MAP) estimates (generated by the HMM forwardbackward algorithm). Both algorithms contain a tuneable parameter which selects the tendency of the processing to replicate ML or MAP estimates. In the limit the algorithms reproduce the ML and MAP estimates exactly.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124114563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frequency Estimation/Tracking for Short Data Windows","authors":"J. Kitchen, S. Howard","doi":"10.1109/ISSPA.1996.615752","DOIUrl":"https://doi.org/10.1109/ISSPA.1996.615752","url":null,"abstract":"In low signal to noise ratio conditions it becomes difficult to estimate the parameters of a time-varying sinusoidal waveform where only a short data record is available at any one time instant. We show how the Discrete Fourier Transform (DFT) may be exploited to obtain a simple frequency estimator, which has a variance in the range one to three times the Cramer-Rao Bound (CRB) for frequency estimation of a sinusoid, even for small data windows. Computer simulations verify the performance of the new estimator and an example demonstrates its utility in tracking the parameters of a modulated waveform in noise.","PeriodicalId":359344,"journal":{"name":"Fourth International Symposium on Signal Processing and Its Applications","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127727818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}