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The evolution of visual communication systems show a dangerous lack of use of new research as well as the enhancement and adaptation of old schemes. So, almost classical time prediction and spatial DC T still survive against new proposals. In parallel, new ideas coming from the images analysis and computer vision areas can increase the speedperformance rate of that schemes, although not modifying...
With the recent growth of networked multimedia systems, techniques are needed to prevent (or at least deter) the illegal copying, forgery and distribution of digital media elements such as audio, images and video. The problem is that a copy of a media element is identical to the original. It is also desirable to determine where and by how much a multimedia element has been changed from the original...
The number of cellular phones sold annually exceeds that of PC's and cars together. The shift to second-generation digital cellular standards has made cellular phones the major application for digital signal processing. In the next few years the 3rd generation cellular standards will be taken in use. This will call for sophisticated DSP algorithms for the radio channel processing implemented in very...
Splines, which were invented by Schoenberg more than fifty years ago [1], constitute an elegant framework for dealing with interpolation and discretization problems. They are widely used in computer-aided design and computer graphics, but have been neglected in signal and image processing applications, mostly as a consequence of what I call the “bad press” phenomenon. Thanks to some recent research...
In the paper we concentrate on a Wavelet-based technique of image refinement. Specifically, we are aimed to obtain the extended version of an original image while preserving its quality. The image to be expanded is given in a non-compressed gray-scale format. According to the method we propose, original image is, heuristically, supposed to be a smoothed version of an unknown sharp image we try to...
DURING the last two decades, the role of digital signal processing (DSP) has changed drastically. Twenty years ago, DSP was mainly a branch of applied mathematics. At that time, the scientists were aware of how to replace continuous-time signal processing algorithms by their discrete-time counterparts providing many attractive properties. These include, among others, a higher accuracy, a higher reliability,...
The design of optimal nonlinear filters for signal processing has involved mostly nonparametric estimation. This paper discusses the elements of parametric design for analog signal processing. It provides details for the class of conjunctive homothetic granulometric bandpass filters. These are nonlinear and their optimization in the signal-union-noise model for random sets can be completely characterized...
This paper develops new algorithms belonging to the class of context modeling methods, with direct application to lossless coding of gray level images. The prediction stage and the context modeling stage are performed using one or more linear predictors based on the regressive analysis.
We have constructed a dynamic face model, which is based on the anatomical structures of a real face. Accurate head geometry was obtained from Magnetic Resonance Images (MRIs). An image segmentation program was used to convert the volumetric MRI data to a polygonal representation of the head. The most detailed models we have used have contained approximately 35000 vertices and 70000 polygons. We have...
Many models based on Hidden Markov Models were developped to modelise errors burst in communication channels. In this paper, we employ the widely used Gilbert model to modelise error bursts and evaluate the effects of interleaving. We derive an expression for the transition matrix in the presence of an interleaver. Starting from an identified error model, it is possible to simulate easily the effects...
In this paper we present our recent work in implementing Serbian spoken dialogue system for the bus information retrieval at the main Belgrade bus station. Dialogue is organized into several levels. At each level, system has to recognize a limited number of keywords in continuous speech of Serbian. The keywords were modeled by HMMs (Hidden Markov Models) in such a way that each syllable is three-state...
In this work, we present a technique designed for improving the subjective quality of still and video images presenting lack of sharpness. The technique employs a wavelet image representation based on edges extracted at different resolution levels by smoothed differential operators [1], and makes use of non-linear processing in the multiresolution edge domain. In this contribution, after a concise...
This paper presents a new context dependent tone recognition method. First we suggest that there be more than five tone modes in Chinese continuous speech. We get all new tone modes by grouping all tone feature vectors to a specific number of categories. Secondly, we recognize a sentence with the new tone modes and get the new tone sequence. Finally, we find out each original tone of the sentence...
Prime factor fast algorithms are computationally efficient for various discrete transforms. However, they generally need an index mapping process to convert one-dimensional input sequence into a two-dimensional array, which results in a substantially computational overhead and an irregular computational structure. This letter attempts to minimize the computation overhead by a simple and general mapping...
A technique is presented to construct a muniscale representation of planar contours based on the multiwavelet transform (MWT). To generate this multiwavelet description, a partial 1-D discrete multiwavelet transform (DMWT) is applied to the vertical and horizontal components of a length-parametrized planar curve. This muniscale representation descomposes the curve into different levels of resolution...
With the diffusion of large video databases and "electronic program guides", the problem of semantic video indexing is of great interest. In literature we can find many video indexing algorithms, based on various types of low-level features, but the problem of semantic video indexing is less studied and surely it is a great challenging one. In this paper we present a particular semantic...
The implementation of analog adaptive median filters for image processing is presented. The adaptive median filter is based on transconductance comparators, which saturation current is adapted to act as a local weight operator. Transistor level simulations, using 1.2mm parameters, have shown excellent results in high removing incidence noise. An image with 249 × 209 corrupted with 35% salt and pepper...
In this work, a cross-disciplinary approach was presented for the solution of a biomedicai pattern recognition problem: cancer diagnosis. Specifically, prostate specimen images were analyzed. Images were acquired by a microscope, video camera and a digitizing board and stored on a computer. The software required to indicate the areas of interest of the tissue image to the pathologist, was developed...
In this paper, we describe a new carrier phase estimator, called TD estimator, suited to transmission schemes based on convolutional turbo-codes. The foreseen application is multimedia telecommunication systems with geostationary satellites at Ka-band. For these systems, the on-board receiver has to operate at low SNR to fulfill up-link link budgets and the critical point is the carrier phase recovery...
A phonetic vocoding system for Finnish is described. This very low bit rate speech coding method is a subclass of segmental vocoding. The proposed system utilizes speech recognition based on a HMM system to phonetically segment and label the input speech. The fundamental frequency is estimated using a robust pitch tracking algorithm. Speech reconstruction is carried out with a conventional LPC speech...
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