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A new region-based algorithm is proposed for the compression of multispectral images. The image is segmented in homogeneous regions, each of which is subject to spectral KLT, spatial shape-adaptive DWT, and SPIHT encoding. We propose to use a dedicated KLT for each region or for each class rather than a single global KLT. Experiments show that the classified KLT guarantees a significant increase in...
The aim of this study is to present a method that predicts unexplained syncope or presyncope occurrences induced by a head-upright tilt-test (HUTT). The HUTT is based on the reproduction of symptoms in combination with hypotension and bradycardia induced by a tilt at 70° during 45 minutes. The main drawback is the duration of this test because, by adding the supine position of 10 minutes, the test...
In the last years, the development of novel video coding technologies has spurred the interest in developing digital video communications. The definition of evaluation mechanisms to assess the quality of video will play a major role in the overall design of video communication systems. It is well-known that simple energy based metrics such as the Peak Signal Noise Ratio (PSNR) are not suitable to...
This paper presents a novel tool, based on Simulink™, for model-based high-level HW/SW codesign of high-performance digital signal processing systems. The tool has been tailored to support HW/SW configurable platforms, in particular those from Sundance Microprocessor Technology [1].
This paper proposes a blind image separation method using wavelet transform and an entropy-maximization algorithm. Our blind separation algorithm is an improved version of the entropy-maximization algorithms presented by Bell-Sejnowsky and Amari. These algorithms work well for signals having a supergaussian distribution, such as speech and audio. The proposed method is to apply the improved algorithm...
A robust space-time-frequency signal extraction algorithm has been developed with an application to brain computer interface (BCI). The algorithm is based on extending time-frequency masking methods to accommodate the spatial domain. The space-time-frequency masks are then clustered in order to extract the desired source. Then the motion of the extracted source it tracked over the scalp. Finally,...
This paper deals with the possibility of improving the concealment effectiveness of an H.264 decoder, by means of the integration of a scene change detector. This way, the selected recovering strategy is driven by the detection of a change in the scene, rather than by the coding features of each frame. The scene detection algorithm under evaluation has been chosen from the technical literature, but...
In this paper, we present a specific algorithm for the blind identification of a two input two output system. A closed form solution for the blind identification of the system is derived by exploiting the temporal coherence properties of the input sources. By exploiting the inherent indeterminacies of the blind processing, a simplified version is derived making the algorithm computationally cheaper...
Sharpness enhancement is one of the post-processing stages in the consumer electronics video chain that operates in an open-loop mode. Although adaptive behavior is possible, in general there is no feedback system aimed at maximizing perceived quality. In this paper we introduce a control system and metric for sharpness enhancement algorithms. We also discuss the options of implementing an internal...
This paper proposes a novel method to detect smoke in video. It is assumed the camera monitoring the scene is stationary. The smoke is semi-transparent at the early stages of a fire. Therefore edges present in image frames start loosing their sharpness and this leads to a decrease in the high frequency content of the image. The background of the scene is estimated and decrease of high frequency energy...
In this paper, a human face detection algorithm in images and video is presented. After determining possible face candidate regions using colour information, each region is filtered by a high-pass filter of a wavelet transform. In this way, edges of the region are highlighted, and a caricature-like representation of candidate regions is obtained. Horizontal, vertical, filter-like and circular projections...
In this paper an objective No Reference metric for assessing the quality degradations introduced by transmission over a heterogeneous IP network is presented. The proposed approach is based on the analysis of the interframe correlation measured at the output of the rendering application. It does not require information about the kind of errors, delays and latencies that affected the link and countermeasures...
Scalable 3D video codecs based on wavelet lifting structures have attracted recently a lot of attention, due to their compression performance comparable with that of state-of-art hybrid codecs. In this work, we propose a set of linear and nonlinear predictors for the temporal prediction step in lifting implementation. The predictor uses pixels on the motion trajectories of the frames in a window around...
Reconstruction of an image from a set of projections has been adapted to generate multidimensional nuclear magnetic resonance (NMR) spectra, which have discrete features that are relatively sparsely distributed in space. For this reason, a reliable reconstruction can be made from a small number of projections. This new concept is called Projection Reconstruction NMR (PR-NMR). In this paper, multidimensional...
In this paper we propose an asymmetric cryptography as subset of digital hologram watermarking, which is able to detect malicious tampering while tolerating some incidental distortions. It is a fragile watermark; in fact the mark is readily altered or destroyed when the host image is modified through a linear or nonlinear transformation. The proposed technique could be applied to Color Images as well...
Automatic discrimination of speech and music is an important tool in many multimedia applications. This paper presents an evolutionary fuzzy rules-based speech/music discrimination approach for intelligent audio coding. A low complexity but effective feature, called Warped LPC-based Spectral Centroid (WLPC-SC), is defined for the analysis stage of the discrimination system. The final decision is made...
The aim of this paper is to combine the strengths of two recently proposed Blind Source Separation (BSS) algorithms. The first algorithm, abbreviated as EFICA, is a sophisticated variant of the well-known Independent Component Analysis (ICA) algorithm FastICA. EFICA is based on minimizing the statistical dependencies between the instantaneous (marginal) distributions of the estimated source signals...
Mouth segmentation is an important issue which applies in many multimedia applications as speech reading, face synthesis, recognition or audiovisual communication. Our goal is to have a robust and efficient detection of lips contour in order to restore as faithfully as possible the speech movement. We present a methodology which focused on the detection of the inner and outer mouth contours which...
The paper describes a prospective multimodal system ICanDo (Intellectual Computer AssistaNt for Disabled Operators) developed in SPIIRAS and intended for assistance to persons without hands or with disabilities of their hands or arms in human-computer interaction. This system combines the modules for automatic speech recognition and head tracking in one multimodal system. The architecture of the system,...
The identifiability problem of the cubic phase function (CPF) for multicomponent quadratic FM (QFM) signals is verified both in theory and in simulations. A computationally efficient technique based on the one dimensional (1-D) Radon-CPF transform (RCT) is proposed for this problem. The RCT first reassigns the time-frequency rate distribution (TFRD) with the information of the second-order coefficient,...
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