Search results for " Enhancement"

Security Enhancement of Peer-to-Peer Session Initiation

2012

Today, Peer-to-Peer SIP based communication systems have attracted much attention from both the academia and industry. The decentralized nature of P2P might provide the distributed peer-to-peer communication system without help of the traditional SIP server. However, the decentralization features come to the cost of the reduced manageability and create new concerns. Until now, the main focus of research was on the availability of the network and systems, while few attempts are put on protecting privacy. In this chapter, we investigate on P2PSIP security issues and introduce two enhancement solutions: central based security and distributed trust security, both of which have their own advanta…

A Sub-Symbolic Approach to Word Modelling for Domain Specific Speech Recognition

2006

In this work a sub-symbolic technique for automatic, data driven language models construction is presented. Such a technique can be used to arrange a language-modelling module, which can be easily integrated in existing speech recognition architectures, such as the well-found HTK architecture. The proposed technique takes advantages from both the traditional LSA approach and from a novel application of a probability space metric known as "Hellinger's distance". Experimental trials are also presented, in order to validate the proposed approach.

Restoration and Enhancement of Historical Stereo Photos Through Optical Flow

2021

Restoration of digital visual media acquired from repositories of historical photographic and cinematographic material is of key importance for the preservation, study and transmission of the legacy of past cultures to the coming generations. In this paper, a fully automatic approach to the digital restoration of historical stereo photographs is proposed. The approach exploits the content redundancy in stereo pairs for detecting and fixing scratches, dust, dirt spots and many other defects in the original images, as well as improving contrast and illumination. This is done by estimating the optical flow between the images, and using it to register one view onto the other both geometrically …

Artificial mosaics

2005

Art often provides valuable insight that can be applied to technological innovations, especially in the fields of image processing and computer graphics. In this paper we present a method to transform a raster input image into a good-quality mosaic: an “artificial mosaic.” The creation of mosaics of artistic quality is challenging because the tiles that compose a mosaic, typically small polygons, must be packed tightly and yet must follow and emphasize orientations chosen by the artist. The proposed method can reproduce the colors of the original image and emphasize relevant boundaries by placing tiles along edge directions. No user intervention is needed to detect the boundaries: they are …

Morse Description and Geometric Encoding of Digital Elevation Maps

2004

Two complementary geometric structures for the topographic representation of an image are developed in this work. The first one computes a description of the Morse-topological structure of the image, while the second one computes a simplified version of its drainage structure. The topographic significance of the Morse and drainage structures of digital elevation maps (DEMs) suggests that they can been used as the basis of an efficient encoding scheme. As an application, we combine this geometric representation with an interpolation algorithm and lossless data compression schemes to develop a compression scheme for DEMs. This algorithm achieves high compression while controlling the maximum …

Effects of predator and shelter conditioning on hatchery-reared white seabream Diplodus sargus (L., 1758) released at sea

2012

Abstract The behavioural deficit of hatchery reared (HR) fish used for stock enhancement is the main cause of their low survival in the wild. In this study the effects of predator and shelter conditioning on survival and dispersal of HR white seabream ( Diplodus sargus ) released at sea were investigated. The hypotheses were that conditioned white seabream would avoid predators more efficiently and would be more capable to shelter, showing higher survival and smaller dispersal than naive fish. Six thousand HR white seabream (6.32 ± 0.93 cm total length) were allocated in twelve plastic tanks and divided in four experimental groups: three groups were conditioned with a predator, a refuge or …

Towards a Non-Intrusive Context-Aware Speech Quality Model

2020

Understanding how humans judge perceived speech quality while interacting through Voice over Internet Protocol (VoIP) applications in real-time is essential to build a robust and accurate speech quality prediction model. Speech quality is degraded in the presence of background noise reducing the Quality of Experience (QoE). Speech Enhancement (SE) algorithms can improve speech quality in noisy environments. The publicly available NOIZEUS speech corpus contains speech in environmental background noise babble, car, street, and train at two Signal-to-noise ratio (SNRs) 5dB and 10dB. Objective Speech Quality Metrics (OSQM) are used to monitor and measure speech quality for VoIP applications. Th…

2020

One crucial parameter to evaluate the state of the heart after myocardial infarction (MI) is the viability of the myocardial segment, i.e., if the segment recovers its functionality upon revascularization. MRI performed several minutes after the injection of a contrast agent (delayed enhancement-MRI or DE-MRI) is a method of choice to evaluate the extent of MI, and by extension, to assess viable tissues after an injury. The Emidec dataset is composed of a series of exams with DE-MR images in short axis orientation covering the left ventricle from normal cases or patients with myocardial infarction, with the contouring of the myocardium and diseased areas (if present) from experts in the dom…

Automatic Processing Scheme for Low Laser Invasiveness Electro Optical Frequency Mapping mode

2016

International audience; Electro optical techniques are efficient backside contactless techniques usually used for design debug and defect location in modern VLSI. Unfortunately, the signal to noise ratio is quite low and depends on laser power with potential device stress due to long acquisition time or high laser power, especially in up to date technologies. Under these conditions, to maintain a good signal or image quality, specific signal or image processing techniques can be implemented. In this paper, we proposed a new spatial filtering by stationary wavelets and contrast enhancement which allows the use of low laser power and short acquisition time in image mode.

Janus Micelles Induced by Olefin Metathesis

2008

A facile one-step procedure for hydrophobic modification and simultaneous TEM contrast enhancement via a regioselective olefin metathesis reaction using Grubbs' catalyst is presented. Polyether diblock copolymers were investigated, and both the chain ends of the hydrophilic and the hydrophobic block were hydrophobically modified. Modification of the hydrophilic block results in nonsymmetric supramolecular structures (Janus micelles) which self-assemble into larger hierarchically organized super-micelles.