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Non-Linear Signal and Image Processing (Ref. No. 1998/284), IEE Colloquium on

Date 22 May 1998

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Displaying Results 1 - 15 of 15
  • A nonlinear processing technique for removing coherent interference artefacts

    Publication Year: 1998, Page(s):1/1 - 1/5
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (568 KB)

    Ultrasound pulses propagating through human tissue appear to retain most of their initial coherence, and are coherently scattered from the many inhomogeneities within a tissue. A complex echo field is generated which exhibits many interference effects, the most familiar of these manifests itself as the ubiquitous speckle artefact. Speckle pervades almost all medical ultrasound pulse-echo signals a... View full abstract»

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  • IEE Colloquium on Non-Linear Signal and Image Processing (Ref. No.1998/284)

    Publication Year: 1998
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (72 KB)

    The following topics were dealt with: non-linear processing technique for coherent interference artefacts removal; rank ordering filters morphological properties; video and film restoration; condition monitoring; Volterra nonlinear systems identification using circular inputs; advanced PRNN based non-linear prediction/system identification; hybrid non-linear filters for locating speckled contamina... View full abstract»

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  • Fast implementation of non-linear filters using FPGAs

    Publication Year: 1998, Page(s):13/1 - 13/5
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (396 KB)

    Most adaptive image and signal processing tasks are performed on specialist digital signal processing chips. These devices are highly optimised for efficient computation of the core multiply and accumulate operations required by current algorithms. Attempts to synthesise these types of algorithms on FPGAs have resulted in few competitive implementations. FPGAs generally fail to realise efficient a... View full abstract»

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  • The Bayesian approach to signal modelling

    Publication Year: 1998, Page(s):9/1 - 9/5
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (336 KB)

    In this paper, an introduction to Bayesian methods in signal processing is given. The paper starts by considering the important issues of model selection and parameter estimation and derives analytic expressions for the model probabilities of two simple models. The idea of marginal estimation of certain model parameters is then introduced and expressions are derived for the marginal probability de... View full abstract»

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  • Video and film restoration using mathematical morphology

    Publication Year: 1998, Page(s):3/1 - 3/5
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (780 KB)

    All those who have visited the cinema will be familiar with the problem of film dirt, i.e. dark artefacts corrupting the images viewed. It is obviously desirable to remove this corruption, especially if one wishes to sell digital versions of the film. This type of film dirt is only present in the luminance fields of the sequence. So, in order to remove this corruption, a suitable filter is applied... View full abstract»

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  • Reducing chromatic grain noise in film sequences

    Publication Year: 1998, Page(s):5/1 - 5/5
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (304 KB)

    Grain noise is one of the most common distortions in cinematographic film sequences and is caused by the crystal structure of the chemical coating of the film material. The colour sensitive crystals can be considered as three separate populations. Thus noise in the three channels is uncorrelated and similarly noise between frames is uncorrelated. Conversely, the signal (i.e. the projected view vol... View full abstract»

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  • Hybrid non-linear filters for locating speckled contaminants in grain

    Publication Year: 1998, Page(s):12/1 - 12/5
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (464 KB)

    This paper discusses the possible application of morphological operators to the inspection of grain. The particular task that is involved is that of locating contaminants such as rodent droppings. In the following section we describe the background to the problem and show the result of applying morphological operators and nonlinear filters to grain images in order to locate contaminants. We analys... View full abstract»

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  • Measuring noise in colour images

    Publication Year: 1998, Page(s):8/1 - 8/4
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (196 KB)

    Algorithms exist for removing unwanted noise from colour images; however little has been said about how to actually quantify the effect of these algorithms or generally how to quantify the amount of noise in a colour image. The standard methods include calculating the normalised mean square error (NMSE) between the original and the filtered image, calculating the mean chromaticity error (MCRE) bet... View full abstract»

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  • Morphological properties of rank ordering filters

    Publication Year: 1998, Page(s):2/1 - 210
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1320 KB)

    When performing tasks such as image segmentation and region coding, it is important to preserve the shape of the regions as closely as possible to those of the original object shapes. For the purposes of data compression it may then be prudent to allow some simplification of the region boundaries in a controlled manner (Beaumont 1996). To improve the segmentation of the image it is usual to filter... View full abstract»

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  • Nonlinear and nonstationary signal processing

    Publication Year: 1998
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (80 KB)

    Presents a brief discussion of the need for and evolution to nonlinear and nonstationary signal processing. Applications where these are useful are mentioned View full abstract»

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  • Identification of Volterra nonlinear systems using circular inputs

    Publication Year: 1998, Page(s):10/1 - 10/6
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (284 KB)

    It is shown that the minimum-mean square estimate of the parameters of a Volterra model can be obtained in closed form when the input is circularly symmetric. The proposed method is applicable to systems with arbitrary orders and memory. Theoretical results are illustrated via Monte-Carlo simulations View full abstract»

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  • Condition monitoring with non-linear signal processing

    Publication Year: 1998, Page(s):4/1 - 4/5
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (352 KB)

    Condition monitoring plays a vital and indispensable role in the operation of any type of plant or machinery. In general, condition monitoring is achieved by processing and interpreting some characteristic signal from the plant under consideration. Traditionally, only linear second order statistical analysis has been used to process the characteristic signals from plant, however, a new approach to... View full abstract»

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  • Image distortions produced by mean, median and mode filters

    Publication Year: 1998, Page(s):6/1 - 6/5
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (360 KB)

    Median filters are probably the most widely used of the noise suppression filters that are commonly applied to digital images. They are vastly superior to mean filters since the latter are well known to blur images as well as removing noise. Median filters do not suffer from this disadvantage. Although median filters do not blur images, it has been found that they can cause a certain amount of ima... View full abstract»

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  • Advanced PRNN based nonlinear prediction/system identification

    Publication Year: 1998, Page(s):11/1 - 11/6
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (328 KB)

    Insight into the core of the pipelined recurrent neural network (PRNN) in prediction applications is provided. It is shown that modules of the PRNN contribute to the final predicted value at the output of the PRNN in two ways, namely through the process of nesting, and through the process of learning. A measure of the influence of the output of a distant module to the amplitude at the output of th... View full abstract»

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  • Two applications of simple non-linear signal processing

    Publication Year: 1998, Page(s):7/1 - 7/6
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (380 KB)

    This paper describes two different applications of nonlinear signal processing. In both cases, computational simplicity was a major goal and a nonlinear approach significantly increased performance. The two applications (PSK demodulation of a noisy signal from sign-only data, and frequency estimation of a single complex tone) are both of practical importance. It is also hoped that these two exampl... View full abstract»

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