Blind image quality assessment through anisotropy

We describe an innovative methodology for determining the quality of digital images. The method is based on measuring the variance of the expected entropy of a given image upon a set of predefined directions. Entropy can be calculated on a local basis by using a spatial/ spatial-frequency distribution as an approximation for a probability density function. The generalized Rényi entropy and the normalized pseudo-Wigner distribution (PWD) have been selected for this purpose. As a consequence, a pixel-by-pixel entropy value can be calculated, and therefore entropy histograms can be generated as well. The variance of the expected entropy is measured as a function of the directionality, and it has been taken as an anisotropy indicator. For this purpose, directional selectivity can be attained by using an oriented 1-D PWD implementation, Our main purpose is to show how such an anisotropy measure can be used as a metric to assess both the fidelity and quality of images. Experimental results show that an index such as this presents some desirable features that resemble those from an ideal image quality function, constituting a suitable quality index for natural images. Namely, in-focus, noise-free natural images have shown a maximum of this metric in comparison with other degraded, blurred, or noisy versions. This result provides a way of identifying in-focus, noise-free images from other degraded versions, allowing an automatic and nonreference classification of images according to their relative quality. It is also shown that the new measure is well correlated with classical reference metrics such as the peak signal-to-noise ratio. © 2007 Optical Society of America.This research has been supported by the following projects: TEC2004-00834, TEC2005-24739-E, TEC2005- 24046-E, and 20045OE184 from the Spanish Ministry of Education and Science and PI040765 from the Spanish Ministry of Health.Peer Reviewe

Texture classification using discrete Tchebichef moments

In this paper, a method to characterize texture images based on discrete Tchebichef moments is presented. A global signature vector is derived from the moment matrix by taking into account both the magnitudes of the moments and their order. The performance of our method in several texture classification problems was compared with that achieved through other standard approaches. These include Haralick's gray-level co-occurrence matrices, Gabor filters, and local binary patterns. An extensive texture classification study was carried out by selecting images with different contents from the Brodatz, Outex, and VisTex databases. The results show that the proposed method is able to capture the essential information about texture, showing comparable or even higher performance than conventional procedures. Thus, it can be considered as an effective and competitive technique for texture characterization. © 2013 Optical Society of America.J. Víctor Marcos is a Juan de la Cierva research fellow funded by the Spanish Ministry of Economy and Competitiveness.Peer Reviewe

Método automático de análisis de señales acústicas no-estacionarias

Método automático de análisis de señales acústicas noestacionarias. Esta patente de invención presenta un método de análisis de la señal acústica temporal generada durante determinados eventos o sucesos de cambio de estado o transformaciones en todo tipo de sistemas físicos caracterizada por presentar una distribución tiempo-frecuencia cualesquiera. Un método basado en un algoritmo matemático permite, después de varias etapas intermedias, la determinación univoca de la cantidad de información (entropía) a partir de un espectro sonoro. Este procedimiento es aplicable a todo sistema de cálculo automático y es de especial interés en ciencias biomédicas, es válido en la determinación de fracturas en estructuras metálicas así como en la prevención de movimientos sísmicos. La presente invención constituye una mejora en los métodos actualmente operativos.Consejo Superior de Investigaciones Científicas (España)B1 Patente con informe sobre el estado de la ténic

Microscopio simple basado en láser y una gota de agua

7 págs.; 7 figs.; 1 tab.© Sociedad Española de Óptica. An educational project based on a laser source and a water drop that acts a single lens is presented allowing to project on a screen the shadows of the objects suspended in the drop.Este trabajo ha sido financiado en parte por el proyecto CTM2014-51907 y por la FECYT. J.L. G-P. agradece al Fondo Social Europeo por financiar parcialmente el programa JAE-Doc y a los proyectos TEC2012-37958-C02-02 del Ministerio de Economía y Competitividad y el proyecto S2013/MIT-2790 (SINFOTON) de la Comunidad Autónoma de MadridPeer Reviewe

Sobre la autonomía constitucional del Servicio Electoral y el control judicial del Tribunal Calificador de Elecciones

Este comentario analiza el alcance de la sentencia del Tribunal Calificador de Elecciones sobre el recurso de queja interpuesto por el pacto electoral “Nueva Mayoría” en contra de la resolución de la Directora (s) del SERVEL ante la negativa de esta de inscribir dicho pacto para las elecciones primarias de Alcalde 2016. La sentencia además de concluir que el Servicio Electoral actuó erradamente al requerir la comparecencia personal de todos los presidentes y secretarios de los partidos políticos, se pronunció sobre la procedencia del recurso de queja ante las actuaciones de dicho Servicio y la sujeción del mismo, como parte de la Administración, al control judicial. El comentario también analiza la forma en que el Tribunal Calificador de Elecciones apreció la prueba en el caso

Primeiro estudo parasitológico em rã com garras Africano (Xenopus laevis, Anfibia) no Chile

Introduced species can arrive into new territories with parasites; however, these species are expected to face lower parasite richness than in their original regions. Both introduced hosts and parasites can affect native fauna. Since their release into the wild in Chile following laboratory use, Xenopus laevis Daudin, 1802 has widely spread throughout central Chile. The only pathogen described on the host is the fungus Batrachochytrium dendrobatidis Longcore, Pessier, Nichols, 1999; thus, this is the first parasitological study of this species in Chile. In 10 localities in central Chile, 179 specimens of X. laevis were captured and examined for parasites in the gastrointestinal tube, cavities, lungs, liver, and skin. Only nine specimens of the genus Contracaecum Railliet, Henry, 1912 were found in six specimens of X. laevis from a private dam in La Patagua. It is likely that these parasites originated from species of native birds. This is the first record of Contracaecum sp. in Chilean amphibians.Espécies exóticas podem se introduzir em um novo território com seus parasitas, porém nesses casos, a riqueza parasitária seria menor. Contudo, hospedeiros exóticos e seus parasitas associados podem afetar a fauna nativa. Depois de ser dispensado do uso em laboratórios e solto em ambientes naturais, Xenopus laevis Daudin, 1802 tem se espalhado massivamente no Chile central. O único patógeno descrito para este anuro é o fungo Batrachochytrium dendrobatidis Longcore, Pessier, Nichols, 1999. O presente estudo constitui a primeira pesquisa parasitológica realizada nesta espécie de rã introduzida no Chile. Em 10 localidades do Chile central, foram capturados 179 espécimes de X. laevis que foram examinadas em busca de parasitos dentro tubo digestivo, cavidades corporais, pulmões, fígado e pele. Nove espécimes do gênero Contracaecum Railliet, Henry, 1912 foram encontrados em seis espécimes de X. laevis de uma barragem em La Patagua. É provável que a origem destes parasitas sejam espécies de aves nativas. Este é o primeiro relato de Contracaecum sp. em anuros do Chile.Fil: Castillo, Cristóbal. Universidad de Concepción; ChileFil: Lobos, Gabriel. Universidad de Chile; ChileFil: González Acuña, Daniel. Universidad de Concepción; ChileFil: Moreno, Lucila. Universidad de Concepción. Facultad de Ciencias Naturales y Oceanografía; ChileFil: Gonzalez, Cynthya Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Landaeta-Aqueveque, Carlos. Universidad de Concepción; Chil

Calidad de servicio en el sistema de comunicación de la “Unidad Educativa CERIT” aplicando calidad de servicio en datos y voz sobre IP.

First of all, an analysis of the needs of the educational community was carried out. For this purpose, the primary communication services used were identified, such as access to virtual platforms, videos, online conferences, file exchange, and others. With this information, it prepared the design of the passive and active network, specifying the structured cabling subsystems; the active network was considered a two-layer design, one for access and the other for core, and the logical design of the network was established through the use of subnets and VLANs. Finally, it carried out quality of service measurements on the system. It properly configured Layer 3 switches, Layer 2 switches, and other network devices to ensure correct data and voice transmission. In addition, it established traffic management and congestion control policies to avoid network interruptions. It implemented the network in the first stage. Once the improvements are made, their impact on the quality of service is evaluated. To this end, surveys were conducted to obtain feedback from the educational community.En primer lugar, se realizó un análisis de las necesidades de la comunidad educativa. Para ello se identificaron los principales servicios de comunicación utilizados, como accesos a plataformas virtuales, acceso a videos, conferencias en línea, intercambio de archivos, entre otros. Con esta información, se elabora el diseño de la red pasiva y activa especificando los subsistemas de cableado estructurado; en la red activa se consideró un diseño en dos capas, una de acceso y otra de core, se estableció el diseño lógico de la red mediante el uso de subredes y VLANs. Finalmente, se diseñó medidas de calidad de servicio en el sistema. Se configuró adecuadamente los switchs capa 3, switch capa 2 y otros dispositivos de red para garantizar una correcta transmisión de datos y voz. Además, se establecieron políticas de gestión de tráfico y control de congestión para evitar interrupciones en la red. Se implementó la red en una primera etapa. Una vez efectuadas las mejoras, se evaluó su impacto en la calidad de servicio. Para ello, se realizaron encuestas para obtener retroalimentación de la comunidad educativa

No-reference image quality assessment through the von Mises distribution

An innovative way of calculating the von Mises distribution (VMD) of image entropy is introduced in this paper. The VMD's concentration parameter and some fitness parameter that will be later defined, have been analyzed in the experimental part for determining their suitability as a image quality assessment measure in some particular distortions such as Gaussian blur or additive Gaussian noise. To achieve such measure, the local R\'{e}nyi entropy is calculated in four equally spaced orientations and used to determine the parameters of the von Mises distribution of the image entropy. Considering contextual images, experimental results after applying this model show that the best-in-focus noise-free images are associated with the highest values for the von Mises distribution concentration parameter and the highest approximation of image data to the von Mises distribution model. Our defined von Misses fitness parameter experimentally appears also as a suitable no-reference image quality assessment indicator for no-contextual images.Comment: 29 pages, 11 figure