Analysis and coding of visual objects: new concepts and new tools

Video coding has been under intense scrutiny during the last years. The published international standards rely on low-level vision concepts, thus being first-generation. Recently standardization started in second-generation video coding, supported on mid-level vision concepts such as objects. This thesis presents new architectures for second-generation video codecs and some of the required analysis and coding tools. The graph theoretic foundations of image analysis are presented and algorithms for generalized shortest spanning tree problems are proposed. In this light, it is shown that basic versions of several region-oriented segmentation algorithms address the same problem. Globalization of information is studied and shown to confer different properties to these algorithms, and to transform region merging in recursive shortest spanning tree segmentation (RSST). RSST algorithms attempting to minimize global approximation error and using affine region models are shown to be very effective. A knowledge-based segmentation algorithm for mobile videotelephony is proposed. A new camera movement estimation algorithm is developed which is effective for image stabilization and scene cut detection. A camera movement compensation technique for first-generation codecs is also proposed. A systematization of partition types and representations is performed with which partition coding tools are overviewed. A fast approximate closed cubic spline algorithm is developed with applications in partition coding.A codificação de vídeo tem sido intensamente estudada nos últimos anos. As normas internacionais já publicadas baseiam-se em conceitos da visão de baixo nível, sendo portanto de primeira geração. Começou recentemente a normalização de técnicas de codificação de segunda geração, suportada em conceitos da visão de médio nível tais como objectos. Esta tese apresenta novas arquitecturas para codificadores de vídeo de segunda geração e algumas das correspondentes ferramentas de análise e codificação. Apresentam-se fundamentos de teoria dos grafos aplicada à análise de imagem e propõem-se algoritmos para generalizações do problema da árvore abrangente mínima. Mostra-se que versões básicas de vários algoritmos de segmentação orientados para a região resolvem o mesmo problema. Estuda-se a globalização de informação e mostra-se que confere propriedades diferentes a esses algoritmos, transformando o algoritmo de fusão de regiões no algoritmo de árvores abrangentes mínimas recursivas (RSST). Mostra-se a eficácia de algoritmos RSST que tentam minimizar o erro global de aproximação e que usam modelos de região afins. Propõe-se um algoritmo baseado em conhecimento prévio para segmentação em vídeo-telefonia móvel. Desenvolve-se um algoritmo de estimação de movimentos de câmara eficaz na estabilização de imagem e na detecção de mudanças de cena. Propõe-se também uma técnica de compensação de movimentos de câmara para codificadores de primeira-geração. Sistematizam-se os tipos e as representações de regiões, revendo-se depois técnicas de codificação de partições. Desenvolve-se um algoritmo rápido e aproximado para cálculo de splines cúbicas fechadas.Programas Ciência e Praxis - JNICT Projecto RACE MAVT - CEC ISCT

Additíons and corrections to the mycological catalogue of Madeira (Portugal).

[EN] From the 164 col1ections of fungi obtained during our 2007 forays in Madeira, more than 30 species seem to be new to the previous catalogue. Among them we could mentíon the fol1owing ones: Bisporella citrina, Scutellinia setosa, Tuber puberulum, within the Ascomycota and Amanita aff. eliae, Chroogomphus fulmineus, Crepidotus applanatus, Galerina hypnorum, Gymnopilus picreus, Hygrocybe insipida, Hypholoma capnoides, Inocybe brunnea, Melanoleuca decembris, Phellinus ferruginosus, Pisolithus arhizus, Pluteus thomsonii, Ripartites metrodii, Russula paludosa and Stereum insignitum for the Basidiomycota. Two Myxomycota: Arcyria oerstedii and Trichiafavoginea are also included. As a result ofthis study, 32 new taxa have been included in the catalogue, compiling a total of 281 taxa identified by us in Madeira until now. Several other species not studied, for absence of the material, but kept through photograpphs are also listed.[ES] De las 164 colecciones de hongos recolectadas durante las excursiones realizadas en 2007 en Madeira, más de 30 especies parecen ser nuevas para el catálogo previo. Entre todas podríamos destacar como más interesantes las siguientes: Bisporella citrina, Scutellinia setosa, Tuber puberulum dentro de los Ascomycota. y Amanita aff. eliae, Chroogomphus fulmineus, Crepidotus applanatus, Galerina hypnorum, Gymnopilus picreus, Hygrocybe insipida, Hypholoma capnoides, Inocybe brunnea, Melanoleuca decembris, Phellinus ferruginosus, Pisolithus arhizus, Pluteus thomsonii, Ripartites metrodii, Russula paludosa y Stereum insignitum entre los Basidiomycota. Además se dan dos especies de Myxomycota: Arcyria oerstedii y Trichiafavoginea. Como resultado de este estudio, se añaden 32 especies más al catálogo anterior, alcanzando la cifra de 281 taxones los identificados por nosotros hasta ahora en Madeira. Otras especies, recolectadas durante las excursiones y fotografiadas, se incluyen en forma de listado.Peer reviewe

Holcus azoricus M. Seq. & Castrov. (Poaceae), a new species from the Azores Islands

A new species of Holcus L. (Poaceae), endemic to the Azores archipelago (Portugal), is described. The vegetative and reproductive structures were studied. The diagnostic characters were compared with those of closely related species. New chromosome counts in Holcus azoricus M. Seq. & Castrov. (2n = 35) and H. rigidus Hochst. (2n = 28) are included. A possible hybrid origin is hypothesized; the potential parents are H. lanatus L. and H. rigidus.info:eu-repo/semantics/publishedVersio

Novedades nomenclaturales en el género "Holcus" (Poaceae).

Nomenclatural novelties in the genus Holcus (Poaceae)Palabras clave. Nomenclatura, Holcus, Poaceae.Key words. Nomenclature, Holcus, Poaceae

Holcus pintodasilvae (Poaceae, Pooideae, Poeae), a new species from the Island of Madeira (Portugal), and notes on Macaronesian Holcus

A new species of Holcus L. (Poaceae), endemic to the island of Madeira (Portugal), is here described as H. pintodasilvae M. Seq. & Castrov. This new species is morphologically closely related to the Macaronesian endemics H. rigidus Hochst. ex Hochst. (Azores Archipelago) and H. mollis L. subsp. hierrensis Stierst. (El Hierro Island, in the Canary Islands) but differs by having the culm nodes light brown, the leaves with a glabrous sheath and subspreading lamina attenuated to an acuminate apex, the glumes blunt, shiny, glabrous (except in the minutely scabrous veins), the upper glume with proximal lateral veins, and the lemma of the upper floret with an awn ca. 4 mm, twice as long as the lemma. Chromosome counts in H. pintodasilvae are tetraploid (2 n = 28). Morphology, ecology, biogeog raphy, and conservation issues are discussed and related to other Macaronesian Holcus taxa. Holcus (totaling less than 20 individuals), and its IUCN conservation status is Critically Endangered (CR). A new specific status is proposed for H. mollis subsp. hierrensis, as H. hierrensis (Stierst.) Stierst. & M. Seq., based on its chromosome number and morphological identity.Descreve-se uma nova especie, Holcus pintodasilvae M. Seq. & Castrov., pertencente ao genero Holcus L. (Poaceae), endemica da Ilha da Madeira (Portugal). Morfologicamente proxima dos endemismos macaronesicos H. rigidus Hochst. ex Hochst. (Arquipelago dos Agores) e H. mollis L. subsp. hierrensis Stierst. (Ilha de Hierro, Arquipelago das Canarias) diferencia-se por possuir: nos de ; folhas com bainhas glabras i apice acumi nado; glumas brilhantes, muticas e glabras (excepto nas nervuras que se apresentam escabriusculas), gluma superior com as nervuras laterais proximais; lema da flor superior com arista ca. 4 mm (duas vezes da contagem de cromossomas de H. pintosilvae (2 n = 28). Discutem-se, e relacionam-se com outros taxa Macaronesicos do genero Holcus, aspectos relativos a morfologia, ecologia, biogeografia e conservagao. Holcus pintodasilvae foi encontrado em apenas tres populagoes (num total de menos de 20 indivfduos), sendo o seu estado de conservagao IUCN esta criticamente ameagado (CR). Propoe-se ainda a combinagao H. hierrensis (Stierst.) Stierst. & M.info:eu-repo/semantics/publishedVersio

Darwin, Hooker and Arruda Furtado and the palaeobotany of Azores: Rediscovering the first collections

The historical investigation of the palaeobotany of the Azores Islands led to the recent rediscovery of the leaf fos sils initially collected by Arruda Furtado in the late 19th century. Advised by Sir Charles Darwin and Sir Joseph Dalton Hooker to search for plant fossils, Arruda Furtado found the first specimens in São Miguel Island, and sent them to the UK for further identification. A recent search at the Natural History Museum, UK, revealed that from a total of sixteen specimens, only one specimen survived. In the same tray, two undescribed specimens from Furnas (São Miguel) were found. Here we describe and identify them as Woodwardia radicans, Laurus azorica and an unidentified fern. The taphonomy indicates that these fossils were preserved in a trachytic tuff, possibly related to the explosive episodes of the Furnas volcano, indicating that they could be late Pleistocene to Holocene in age. This report aims to highlight the potential of future palaeobotanical studies of the Azores Islands.info:eu-repo/semantics/publishedVersio

Rediscovering of Chara braunii (Characeae, Charophyta) in Madeira (Macaronesian region, Portugal)

Chara braunii C.C. Gmelin (Characeae, Charophyta) was found in Madeira Island (Portugal) in a water channel in an agricultural area. This constitutes the first record of that species since 1944 in the Macaronesian region (Azores, Madeira and Canary archipelagos).Chara braunii C.C. Gmelin (Characeae, Charophyta) ha sido encontrado en un canal de riego de la isla de Madeira (Portugal) en una zona de intensa actividad agrícola. Se trata de la primera cita de esta especie desde 1944 en la región Macaronérica, formada por los archipiélagos de Azores, Madera y Canarias.info:eu-repo/semantics/publishedVersio

La especie endémica de la laurisilva de Madeira, Goodyera macrophylla (Orchidaceae), está relacionada con orquídeas americanas

Macaronesian laurel forests harbour many herbs and laurophyllous trees with Mediterranean/European or Macaronesian affinities. Traditionally, the origin of these taxa has been explained by the relict hypothesis interpreting these taxa as relics of formerly widespread laurel forests in the European continent and the Mediterranean. We analysed the phylogenetic relationships of the Madeiran laurel forest endemic Goodyera macrophylla (Orchidaceae) using sequences from the nuclear ribosomal DNA Internal Transcribed Spacers (ITS) and plastid DNA regions. The results were incongruent, either the two Central American G. brachyceras and G. striata (ITS) or the North American G. oblongifolia (plastid DNA) were sister group to G. macrophylla. Nonetheless, biogeographic analyses indicated an American origin of this nemoral laurel forest plant in the two data sets. Molecular clock analyses suggest a colonisation of Madeira in the span of the upper Miocene/lower Pliocene to the Pleistocene. Although the relict hypothesis cannot be ruled out by our data when assuming extinction events on the European and northern African mainland, dispersal from Central or North America to the archipelago of Madeira is a much more likely explanation of the data.La laurisilva de la Macaronesia alberga muchos árboles laurófilos y hierbas con afinidades mediterráneo/europeas o macaronésicas. El origen de estos taxones se ha explicado por la hipótesis del bosque relicto que interpretaba estos taxones como relictos de bosques de laurel previamente extendidos en Europa y el Mediterráneo. Analizamos las relaciones filogenéticas de Goodyera macrophylla (Orchidaceae), especie endémica de la laurisilva de Madeira, utilizando secuencias del ADN ribosómico (ITS) y de regiones plastidiales. Los resultados fueron incongruentes: las dos especies de Centroamérica, G. brachyceras y G. striata, emergieron como grupo hermano de G. macrophylla en el análisis de ITS, mientras que G. oblongifolia, de Norteamérica, resultó hermana de G. macrophylla en el análisis plastidial. No obstante, los análisis biogeográficos indicaron un origen en norte america para G. macrophylla en los dos conjuntos de datos. Los análisis del reloj molecular sugieren una colonización de Madeira en el lapso del Mioceno superior/Plioceno inferior al Pleistoceno. Aunque nuestros datos no pueden descartar la hipótesis del bosque relicto, cuando se asumen eventos de extinción en Europa y norte de África, la dispersión desde Centro o Norteamérica al archipiélago de Madeira es una explicación mucho más probable de los datos

Multistage morphology-based license-plate location algorithm

This paper describes a new license-plate location algorithm using a sequential multistage approach, where each stage consists of a different sub-algorithm. All the proposed subalgorithms make use of morphological operations performed over both gray-scale and binary images. In order to ascertain the performance of the proposed algorithm, and to fairly compare it with license-plate location algorithms developed by other authors, a well-defined evaluation method is used. Results have shown that the proposed algorithm produces at least one accurate license-plate location hypothesis for 97.18% of 673 images acquired at a highway toll fence.ISCTE, Living Data, Brisa, S.A

Evaluation of license-plate location algorithms

We propose a new evaluation method for license-plate location algorithms. As a first step towards a comparison of the algorithms described in the literature over the years, we have implemented some relevant algorithms with different approaches and compared them using the proposed evaluation method. The software used for evaluation and a set of annotated evaluation images are both readily available, making the reproduction of the presented results possible. The availability of both software and an evaluation set allows the results presented in this paper to be used as benchmarks when developing plate location algorithms.ISCTE, Living Data, Brisa, S.A