2 research outputs found

    Face Recognition based on Oriented Complex Wavelets and FFT

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    The Face is a physiological Biometric trait used in Biometric System. In this paper face recognition using oriented complex wavelets and Fast Fourier Transform (FROCF) is proposed. The five-level Dual Tree Complex Wavelet Transform (DTCWT) is applied on face images to get shift invariant and directional features along±15o,±45o and±75o angular directions. The different pose, illumination and expression variations of face images are represented in frequency domain using Fast Fourier Transform (FFT) resulting in FFT features. Features of DTCWT and FFT are fused by arithmetic addition to get final features. Euclidean Distance classifier is applied to the features to recognize the genuine and imposter faces. The Performance analysis of proposed method is tested with ORL, JAFFE, L-SPACEK and CMU-PIE having different illumination and pose conditions. The Results shows that Recognition Rate of proposed FROCF is better compared to Existing Recognition Methods

    CaractĂ©risation et interprĂ©tation de l'enregistrement mĂ©tamorphique afin de dĂ©finir les processus d'enfoncement et d'exhumation dans les orogĂšnes (exemple du Massif de BohĂȘme)

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    A range of petrological and structural works carried in the Bohemian Massif largely contributed to establishment of the models of burial and exhumation mechanisms in the external and internal orogenic domains. The eastern margin of the Bohemian Massif is formed by the Brunia microcontinent that was underthrust below the westerly orogenic root of the Moldanubian-Lugian domain. The underthrusting produced in the Brunia basement approximately 50 kilometers wide zone of deformation and metamorphism, called the Moravo-Silesian zone. The Lugian-Moldanubian internal domain forms the core of the orogen and it is characterized by presence of high grade rocks, such as high-pressure felsic granulites, eclogites, garnetiferous and spinel peridotites and migmatites, low-grade rocks and magmatic bodies, preserving a complicated structural and metamorphic history of the deep orogenic root. The presence of high-pressure and low-temperature rocks in the Saxothuringian domain to the west is interpreted as a remnant of a subduction zone.At the south-eastern margin of the Bohemian Massif, two large tectonic windows of the Moravian zone are emerging through a migmatitic nappe of the Moldanubian domain. We have shown that Barrovian prograde metamorphism in these tectonic windows, ranging from chlorite to kyanite zone, is related to continental underthrusting below the orogenic root, and retrograde P−T evolution to nappe stacking and inversion of metamorphic isograds. Complex pattern of isograds that obliquely crosscut tectonic boundaries in a present section is interpreted as a result of late folding of crustal sheets. In the northeastern margin of the Bohemian Massif occurs the Silesian domain, characterized by Barrovian and Buchan type metamorphism. In the kyanite zone, we described eclogite lenses in the metapelite matrix and demonstrated their separate metamorphic histories, indicating mixing of rocks at the tip of the underthrust crustal wedge. Further east, based on chloritoid-staurolite equilibria, we distinguished a high geothermal gradient during prograde metamorphism that is probably associated with inherited heat from a Devonian intracontinental rift, which can also explain the development of Buchan-type metamorphism. In the north-eastern part of the contact between the Lugian domain and the Silesian zone occurs the StarĂ© Město belt, composed of granodiorite, layered amphibolite, metagabbro and serpentinite. Combined structural and geochronological study revealed a structural unconformity between subhorizontal fabrics in the granulites and amphibolites dated at 500 Ma and fabrics of the granodiorite sheet that are parallel to steep foliations reworking the gabbros, dated at 340 Ma on zircon. This allowed distinguishing relics of subhorizontal Ordovician fabrics for the first time in the whole Variscan European belt and interpreting these lithologies as a Cambro-Ordovician intracontinental rift. The Variscan tectono-metamorphic event is manifested by syn-convergent intrusion of the Carboniferous granodiorite sill and by HT-MP compressional deformation of the gabbros that produces foliations parallel with the structure of the granodiorite. Based on these criteria we interpreted the StarĂ© Město belt as a preserved example of an intracontinental Cambro-Ordovician rift that has been reactivated and exhumed during the Variscan orogeny.The studies in the Moldanubian-Lugian orogenic root domain shown that HP conditions are connected with early shallow-dipping fabric, and that HP rocks are exhumed during vertical crustal-scale folding that leads to extrusion of HP rocks along vertical channels. This produces a pattern of large-scale “synforms” cored commonly by HP granulites and large-scale “antiforms” dominated by metasediments. This model of crustal-scale folding and vertical extrusion is proposed as a possible major exhumation mechanism of HP rocks in hot orogens and a potential role of gravity in this process is discussed.Studies of HP granulites from the Moldanubian orogenic root pointed to a problem of interpretation of equilibrium metamorphic assemblages in high-grade rocks and consequently to a problem of determining the peak metamorphic conditions. Classic combination of high-grossular garnet and high-temperature ternary feldspar led to estimation of metamorphic conditions to >1000 °C and 18−28 kbar. Microstructural analysis has shown that mafic granulites contain several generations of garnet, and that ternary feldspar and high-grossular garnet belong to two distinct episodes, and cannot be combined to infer metamorphic conditions. Detailed study of a Morb-type eclogite shows unusually hot prograde conditions that are interpreted as a result of Devonian thermal rejuvenation of continental back arc domain that was responsible for softening of a future orogenic root domain. The steep foliations in the Lugian-Moldanubian domains are to a different degree reworked by shallow-dipping fabrics. At the eastern margin of the Bohemian Massif, kilometre-scale crustal boudins of HP granulites and eclogites enclosed in migmatites are present. The HP lenses experienced first burial to 20 kbar and than exhumation to 10–7 kbar and the mid-crustal rocks revealed increase of pressure to 10 kbar. All the system was re-equilibrated at 7 kbar where the high pressure rocks cooled while mid-crustal rocks became heated. We interpreted this metamorphic pattern as a result of vertically extruded lower-crustal rocks into the middle crust, then travelling as fragments in a subhorizontal hot migmatitic channel above a continental margin. This is interpreted as a continental channel flow domain that developed in the orogenic root above the underthrust Brunia basement, and which is eroded along its total width of 120 km and length of 200 km. A detailed petrological, microstructural and geochemical study of migmatites in the well developed shallow-dipping fabrics of the Moldanubian orogenic root allowed discussion about the evolution of the “channel flow” domain and about the melt migration in the crust. Four migmatite types collected in the steep and shallow-dipping structures show decreasing P−T conditions, indicating exhumation and cooling. Progressive changes in whole rock composition are interpreted in terms of open system behavior, caused by crustal-scale melt infiltration operating at grain boundaries. The mineral-equilibria modelling shown that such “metasomatism” by cirulating melt may cause the observed whole rock composition changes and was suggested as a new mechanism of melt transport in the crust. In order to discuss the effects of melting on large-scale rheology during orogenic root deformations, pseudosection modeling of melt quantities was done to evaluate deformation mechanisms in various high-grade orthogneisses. Simultaneous metamorphic and structural studies of lower- and middle crustal rocks permitted correlation of retrograde and very rarely preserved prograde metamorphic fabrics of the middle and lower orogenic crust, which started discussion of coupled and uncoupled mechanisms of burial and exhumation in the two crustal levels, but also with respect to the upper and lower plate
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