344 research outputs found

    Mapping Images with the Coherence Length Diagrams

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    Statistical pattern recognition methods based on the Coherence Length Diagram (CLD) have been proposed for medical image analyses, such as quantitative characterisation of human skin textures, and for polarized light microscopy of liquid crystal textures. Further investigations are made on image maps originated from such diagram and some examples related to irregularity of microstructures are shown

    Non-photorealistic image rendering with a labyrinthine tiling

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    The paper describes a new image processing for a non-photorealistic rendering. The algorithm is based on a random generation of gray tones and competing statistical requirements. The gray tone value of each pixel in the starting image is replaced selecting among randomly generated tone values, according to the statistics of nearest-neighbor and next-nearest-neighbor pixels. Two competing conditions for replacing the tone values - one position on the local mean value the other on the local variance - produce a peculiar pattern on the image. This pattern has a labyrinthine tiling aspect. For certain subjects, the pattern enhances the look of the image.Comment: 9 pages, 5 figure

    Effects of GIMP Retinex Filtering Evaluated by the Image Entropy

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    A GIMP Retinex filtering can be used for enhancing images, with good results on foggy images, as recently discussed. Since this filter has some parameters that can be adjusted to optimize the output image, several approaches can be decided according to desired results. Here, as a criterion for optimizing the filtering parameters, we consider the maximization of the image entropy. We use, besides the Shannon entropy, also a generalized entropy.Comment: Keywords: Image Processing, Foggy Images, Retinex, Shannon Entropy, Generalized Entropies, Kaniadakis Entrop

    A tour about Isaac Newton's life

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    Here we propose a tour about the life of Isaac Newton, using a georeferenced method, based on the free satellite maps. Our tour is modelled on the time-line of the great scientist's life, as an ancient "itinerarium" was modelled on the Roman roads, providing a listing of places and intervening distances, sometimes with short description or symbols concerning the places. KML language and Google Earth, with its Street View and 3D images are powerful tools to create this virtual tour.Comment: Georeferencing, Satellite Maps, KML, XML, Acme Mapper, History of Physic

    Self frequency-locking of a chain of oscillators

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    The paper studies the vibrational modes of a slightly damped uniform chain, with n masses coupled by elastic forces. It will be shown that, for certain lengths of the chain, that is for certain values of n, the damping of one of the masses at a specific position in the chain is able to constrain the vibration of the system to oscillate at a specific frequency. The damped mass turns out to be a node of the chain, subdividing it in two parts. This node can be considered as the synchronization element of the two subchains. As a consequence the oscillating system of n-masses is self-locking to the synchronized frequency of its subchains

    Undulation textures at the phase transitions of some alkyloxybenzoic acids

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    We observed undulated smectic textures for some compounds of the 4,n-alkyloxybenzoic (nOBAC) acid series, at transitions between the smectic and the isotropic phase and between the smectic and nematic phase. Studied compounds were 12OBAC, 16OBAC and a binary mixture of 12- and 16OBAC. The undulations are dressing a usual Schlieren texture. In the case of the binary mixture, an interesting fingerprint pattern is observed too

    Texture transitions in binary mixtures of 6OBAC with compounds of its homologous series

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    Recently we have observed in compounds of the 4,n-alkyloxybenzoic acid series, with the homologous index n ranging from 6 to 9, a texture transition in the nematic range which subdivides the nematic phase in two sub-phases displaying different textures in polarised light analysis. To investigate a persistence of texture transitions in nematic phases, we prepared binary mixtures of 4,6-alkyloxybenzoic acid (6OBAC) with other members (7-,8-,9-,12-, 16OBAC) of its homologous series. Binary mixtures exhibit a broadening in the temperature ranges of both smectic and nematic phases. A nematic temperature range of 75 C is observed. In the nematic phase, in spite of the microscopic disorder introduced by mixing two components, the polarised light optics analysis of the liquid crystal cells reveals a texture transition. In the case of the binary mixture of 6OBAC with 12OBAC and with 16OBAC, that is of compounds with monomers of rather different lengths, the texture transition temperature is not homogeneous in the cell, probably due to a local variation in the relative concentrations of compounds.Comment: 13 pages, 9 figure

    Composition law of κ\kappa-entropy for statistically independent systems

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    The intriguing and still open question concerning the composition law of κ\kappa-entropy Sκ(f)=12κ∑i(fi1−κ−fi1+κ)S_{\kappa}(f)=\frac{1}{2\kappa}\sum_i (f_i^{1-\kappa}-f_i^{1+\kappa}) with 0<κ<10<\kappa<1 and ∑ifi=1\sum_i f_i =1 is here reconsidered and solved. It is shown that, for a statistical system described by the probability distribution f={fij}f=\{ f_{ij}\}, made up of two statistically independent subsystems, described through the probability distributions p={pi}p=\{ p_i\} and q={qj}q=\{ q_j\}, respectively, with fij=piqjf_{ij}=p_iq_j, the joint entropy Sκ(p q)S_{\kappa}(p\,q) can be obtained starting from the Sκ(p)S_{\kappa}(p) and Sκ(q)S_{\kappa}(q) entropies, and additionally from the entropic functionals Sκ(p/eκ)S_{\kappa}(p/e_{\kappa}) and Sκ(q/eκ)S_{\kappa}(q/e_{\kappa}), eκe_{\kappa} being the κ\kappa-Napier number. The composition law of the κ\kappa-entropy is given in closed form, and emerges as a one-parameter generalization of the ordinary additivity law of Boltzmann-Shannon entropy recovered in the κ→0\kappa \rightarrow 0 limit.Comment: 14 page
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