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Lindahl, Tobias. "Study of Local Binary Patterns." Thesis, Linköping University, Department of Science and Technology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9415.
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<p>This Masters thesis studies the concept of local binary patterns, which describe the neighbourhood of a pixel in a digital image by binary derivatives. The operator is often used in texture analysis and has been successfully used in facial recognition.</p><p>This thesis suggests two methods based on some basic ideas of Björn Kruse and studies of literature on the subject. The first suggested method presented is an algorithm which reproduces images from their local binary patterns by a kind of integration of the binary derivatives. This method is a way to prove the preservation of information. The second suggested method is a technique of interpolating missing pixels in a single CCD camera based on local binary patterns and machine learning. The algorithm has shown some very promising results even though in its current form it does not keep up with the best algorithms of today.</p>
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Chan, Chi Ho. "Multi-scale local Binary Pattern Histogram for Face Recognition." Thesis, University of Surrey, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493135.
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Recently, the research in face recognition has focused on developing a face representation that is capable of capturing the relevant information in a manner which is invariant to facial expression and illumination. Motivated by a simple but powerful texture descriptor, called Local Binary Pattern (LBP), our proposed system extends this descriptor to evoke multiresolution and multispectral analysis for face recognition. The first descriptor, namely Multi-scale Local Binary Pattern Histogram (MLBPH), provides a robust system which is relatively insensitive to localisation errors because it benefits from the multiresolution information captured from the regional histogram.
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Mäenpää, T. (Topi). "The local binary pattern approach to texture analysis — extensions and applications." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514270762.
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Abstract
This thesis presents extensions to the local binary pattern (LBP) texture analysis operator. The operator is defined as a gray-scale invariant texture measure, derived from a general definition of texture in a local neighborhood. It is made invariant against the rotation of the image domain, and supplemented with a rotation invariant measure of local contrast. The LBP is proposed as a unifying texture model that describes the formation of a texture with micro-textons and their statistical placement rules.
The basic LBP is extended to facilitate the analysis of textures with multiple scales by combining neighborhoods with different sizes. The possible instability in sparse sampling is addressed with Gaussian low-pass filtering, which seems to be somewhat helpful.
Cellular automata are used as texture features, presumably for the first time ever. With a straightforward inversion algorithm, arbitrarily large binary neighborhoods are encoded with an eight-bit cellular automaton rule, resulting in a very compact multi-scale texture descriptor. The performance of the new operator is shown in an experiment involving textures with multiple spatial scales.
An opponent-color version of the LBP is introduced and applied to color textures. Good results are obtained in static illumination conditions. An empirical study with different color and texture measures however shows that color and texture should be treated separately.
A number of different applications of the LBP operator are presented, emphasizing real-time issues. A very fast software implementation of the operator is introduced, and different ways of speeding up classification are evaluated. The operator is successfully applied to industrial visual inspection applications and to image retrieval.
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RIBEIRO, M. V. L. "Proposta de Local Binary Pattern Coerente e Incoerente na Categorização de Cenas." Universidade Federal do Espírito Santo, 2017. http://repositorio.ufes.br/handle/10/9682.
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Previous issue date: 2017-10-11<br>Este trabalho propõe um novo descritor visual de cenas a partir da técnica Local Binary Pattern (LBP) e explorando a informação espacial utilizando o algoritmo Color Coherent Vector (CCV). O LBP se caracteriza por ser uma técnica não linear e não paramétrica, dispensando conceitos intermediários no processo de descrição da imagem, tornando uma alternativa para usuários leigos com pouco conhecimento na área. Já a representação CCV mostrou ser uma técnica que busca mitigar o problema da falta de informação espacial pelos histogramas, expressando a imagem em pixeis coerentes e pixeis incoerentes sem que aumente a dimensionalidade dos dados. Nesse sentido, uma primeira abordagem foi a proposta das técnicas LBP Incoerente e LBP Coerente na classificação de cenas. Resultados preliminares, empregando-se K-NN como classificador, demonstraram que o LBP Incoerente apresenta um bom compromisso entre
acurácia e dimensão de representação dos dados. Em seguida, no intuito de se incluir o conceito de contexto, para mitigar o problema da localidade do LBP, foi proposto o Contextual Modified Local Binary Pattern Incoerente (CMLBP Incoerente), que modela a distribuição das estruturas locais através do LBP,
adicionando informação contextual, inspirado no algoritmo Contextual Modified Census Transform (CMCT). Entre outras características, o CMLBP Incoerente demonstrou capacidade em descartar regiões homogêneas, representadas pelos pixeis coerentes através do algoritmo CCV. Em experimentos realizados com bancos de dados consagrados na literatura, o CMLBP apresentou resultados melhores que as técnicas originais que não descartam os pixeis
coerentes, em quase todas as situações. Para cenas com muitos detalhes e informações os resultados foram satisfatórios e com um maior destaque, superando técnicas conhecidas na literatura. Os resultados obtidos foram encorajadores para a busca de um descritor com boa capacidade discriminante e baixa dimensionalidade na representação de imagens.
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Ylioinas, J. (Juha). "Towards optimal local binary patterns in texture and face description." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526214498.
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Abstract Local binary patterns (LBP) are among the most popular image description methods and have been successfully applied in a diverse set of computer vision problems, covering texture classification, material categorization, face recognition, and image segmentation, to name only a few. The popularity of the LBP methodology can be verified by inspecting the number of existing studies about its different variations and extensions. The number of those studies is vast. Currently, the methodology has been acknowledged as one of the milestones in face recognition research. The starting point of this research is to gain more understanding of which principles the original LBP descriptor is based on. After gaining some degree of insight, yet another try is made to improve some steps of the LBP pipeline, consisted of image pre-processing, pattern sampling, pattern encoding, binning, and further histogram post-processing. The main contribution of this thesis is a bunch of novel LBP extensions that partly try to unify some of the existing derivatives and extensions. The basis for the design of the new additional LBP methodology is to maximise data-driven premises, at the same time minimizing the need for tuning by hand. Prior to local binary pattern extraction, the thesis presents an image upsampling step dubbed as image pre-interpolation. As a natural consequence of upsampling, a greater number of patterns can be extracted and binned to a histogram improving the representational performance of the final descriptor. To improve the following two steps of the LBP pipeline, namely pattern sampling and encoding, three different learning-based methods are introduced. Finally, a unifying model is presented for the last step of the LBP pipeline, namely for local binary pattern histogram post-processing. As a special case of this, a novel histogram smoothing scheme is proposed, which shares the motivation and the effects with the image pre-interpolation for the most of its part. Deriving descriptors for such face recognition problems as face verification or age estimation has been and continues to be among the most popular domains where LBP has ever been applied. This study is not an exception in that regard as the main investigations and conclusions here are made on the basis of how the proposed LBP variations perform especially in the problems of face recognition. The experimental part of the study demonstrates that the proposed methods, experimentally validated using publicly available texture and face datasets, yield results comparable to the best performing LBP variants found in the literature, reported with the corresponding benchmarks<br>Tiivistelmä Paikalliset binäärikuviot kuuluvat suosituimpiin menetelmiin kuville suoritettavassa piirteenirrotuksessa. Menetelmää on sovellettu moniin konenäön ongelmiin, kuten tekstuurien luokittelu, materiaalien luokittelu, kasvojen tunnistus ja kuvien segmentointi. Menetelmän suosiota kuvastaa hyvin siitä kehitettyjen erilaisten johdannaisten suuri lukumäärä ja se, että nykyään kyseinen menetelmien perhe on tunnustettu yhdeksi virstanpylvääksi kasvojentunnistuksen tutkimusalueella. Tämän tutkimuksen lähtökohtana on ymmärtää periaatteita, joihin tehokkaimpien paikallisten binäärikuvioiden suorituskyky perustuu. Tämän jälkeen tavoitteena on kehittää parannuksia menetelmän eri askelille, joita ovat kuvan esikäsittely, binäärikuvioiden näytteistys ja enkoodaus, sekä histogrammin koostaminen ja jälkikäsittely. Esiteltävien uusien menetelmien lähtökohtana on hyödyntää mahdollisimman paljon kohdesovelluksesta saatavaa tietoa automaattisesti. Ensimmäisenä menetelmänä esitellään kuvan ylösnäytteistykseen perustuva paikallisten binäärikuvioiden johdannainen. Ylösnäytteistyksen luonnollisena seurauksena saadaan näytteistettyä enemmän binäärikuvioita, jotka histogrammiin koottuna tekevät piirrevektorista alkuperäistä erottelevamman. Seuraavaksi esitellään kolme oppimiseen perustuvaa menetelmää paikallisten binäärikuvioiden laskemiseksi ja niiden enkoodaukseen. Lopuksi esitellään paikallisten binäärikuvioiden histogrammin jälkikäsittelyn yleistävä malli. Tähän malliin liittyen esitellään histogrammin silottamiseen tarkoitettu operaatio, jonka eräs tärkeimmistä motivaatioista on sama kuin kuvan ylösnäytteistämiseen perustuvalla johdannaisella. Erilaisten piirteenirrotusmenetelmien kehittäminen kasvojentunnistuksen osa-alueille on erittäin suosittu paikallisten binäärikuvioiden sovellusalue. Myös tässä työssä tutkittiin miten kehitetyt johdannaiset suoriutuvat näissä osa-ongelmissa. Tutkimuksen kokeellinen osuus ja siihen liittyvät numeeriset tulokset osoittavat, että esitellyt menetelmät ovat vertailukelpoisia kirjallisuudesta löytyvien parhaimpien paikallisten binäärikuvioiden johdannaisten kanssa
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Doshi, Niraj P. "Multi-dimensional local binary pattern texture descriptors and their application for medical image analysis." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/17332.
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Texture can be broadly stated as spatial variation of image intensities. Texture analysis and classification is a well researched area for its importance to many computer vision applications. Consequently, much research has focussed on deriving powerful and efficient texture descriptors. Local binary patterns (LBP) and its variants are simple yet powerful texture descriptors. LBP features describe the texture neighbourhood of a pixel using simple comparison operators, and are often calculated based on varying neighbourhood radii to provide multi-resolution texture descriptions. A comprehensive evaluation of different LBP variants on a common benchmark dataset is missing in the literature. This thesis presents the performance for different LBP variants on texture classification and retrieval tasks. The results show that multi-scale local binary pattern variance (LBPV) gives the best performance over eight benchmarked datasets. Furthermore, improvements to the Dominant LBP (D-LBP) by ranking dominant patterns over complete training set and Compound LBP (CM-LBP) by considering 16 bits binary codes are suggested which are shown to outperform their original counterparts. The main contribution of the thesis is the introduction of multi-dimensional LBP features, which preserve the relationships between different scales by building a multi-dimensional histogram. The results on benchmarked classification and retrieval datasets clearly show that the multi-dimensional LBP (MD-LBP) improves the results compared to conventional multi-scale LBP. The same principle is applied to LBPV (MD-LBPV), again leading to improved performance. The proposed variants result in relatively large feature lengths which is addressed using three different feature length reduction techniques. Principle component analysis (PCA) is shown to give the best performance when the feature length is reduced to match that of conventional multi-scale LBP. The proposed multi-dimensional LBP variants are applied for medical image analysis application. The first application is nailfold capillary (NC) image classification. Performance of MD-LBPV on NC images is highest, whereas for second application, HEp-2 cell classification, performance of MD-LBP is highest. It is observed that the proposed texture descriptors gives improved texture classification accuracy.
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Eriksson, Josefine, and Lindelöf Anna. "Measuring Student Attention with Face Detection: : Viola-Jones versus Multi-Block Local Binary Pattern using OpenCV." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166416.
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The purpose of this study is to discuss and attempt to approach an answer to the question of how face detection could be used to measure attention in a lecture hall.The conclusion might help further studies in using face detection to provide teachers with tools which can be used to improve learning during lectures. Face detection in real time applications became possible in 2001 when Viola and Jones presented a new method several times faster than any previous attempt. In 2007 Liao et al. presented a method using multi-block local binary patterns (MB-LBP) for the purpose of overcoming the simplicity and limitations of the Viola-Jones method. Computer vision libraries such as OpenCV make it easy to implement such algorithms. It currently supports both the Viola-Jones algorithm and the MB-LBP algorithm. This study compared these two face detection methods to see how they perform in terms of sensitivity and precision and attempted to identified limitations of both methods when used to detect attention in a simulated lecture environment. The study was conducted using boosted algorithms and functionality provided by OpenCV. The input data consisted of a recorded simulated lecture with 6 subjects performing different poses, labeled either attention or no attention, during certain periods of time, each pose recognized from a previously recorded actual lecture as a commonly occurring pose. The most significant difference of performance identified in the study was that the MB-LBP method performed face detection in an image three times faster than for Viola-Jones which confirmed previous reported results. Both methods generated high sensitivity values for all poses, but low precision values for two of the poses.The ability of both methods to detect downward tilted faces contributed to a high number of false positives returned when subjects performed the two poses of subjects taking notes or subjects performing activities labeled as no attention. Due to the low precision values caused by this, both methods were not considered to measure attention effectively. It is therefore suggested to instead train a MB-LBP-based method for the specific task of measuring attention in a lecture hall by training it to reject downward-tilted faces and to accept only instances conforming to the chosen definition of attention.
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Nguyen, Thanh Le Vi. "Local Binary Pattern based algorithms for the discrimination and detection of crops and weeds with similar morphologies." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2020. https://ro.ecu.edu.au/theses/2359.
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In cultivated agricultural fields, weeds are unwanted species that compete with the crop plants for nutrients, water, sunlight and soil, thus constraining their growth. Applying new real-time weed detection and spraying technologies to agriculture would enhance current farming practices, leading to higher crop yields and lower production costs. Various weed detection methods have been developed for Site-Specific Weed Management (SSWM) aimed at maximising the crop yield through efficient control of weeds. Blanket application of herbicide chemicals is currently the most popular weed eradication practice in weed management and weed invasion. However, the excessive use of herbicides has a detrimental impact on the human health, economy and environment. Before weeds are resistant to herbicides and respond better to weed control strategies, it is necessary to control them in the fallow, pre-sowing, early post-emergent and in pasture phases. Moreover, the development of herbicide resistance in weeds is the driving force for inventing precision and automation weed treatments. Various weed detection techniques have been developed to identify weed species in crop fields, aimed at improving the crop quality, reducing herbicide and water usage and minimising environmental impacts.
In this thesis, Local Binary Pattern (LBP)-based algorithms are developed and tested experimentally, which are based on extracting dominant plant features from camera images to precisely detecting weeds from crops in real time. Based on the efficient computation and robustness of the first LBP method, an improved LBP-based method is developed based on using three different LBP operators for plant feature extraction in conjunction with a Support Vector Machine (SVM) method for multiclass plant classification. A 24,000-image dataset, collected using a testing facility under simulated field conditions (Testbed system), is used for algorithm training, validation and testing. The dataset, which is published online under the name “bccr-segset”, consists of four subclasses: background, Canola (Brassica napus), Corn (Zea mays), and Wild radish (Raphanus raphanistrum). In addition, the dataset comprises plant images collected at four crop growth stages, for each subclass. The computer-controlled Testbed is designed to rapidly label plant images and generate the “bccr-segset” dataset. Experimental results show that the classification accuracy of the improved LBP-based algorithm is 91.85%, for the four classes.
Due to the similarity of the morphologies of the canola (crop) and wild radish (weed) leaves, the conventional LBP-based method has limited ability to discriminate broadleaf crops from weeds. To overcome this limitation and complex field conditions (illumination variation, poses, viewpoints, and occlusions), a novel LBP-based method (denoted k-FLBPCM) is developed to enhance the classification accuracy of crops and weeds with similar morphologies. Our contributions include (i) the use of opening and closing morphological operators in pre-processing of plant images, (ii) the development of the k-FLBPCM method by combining two methods, namely, the filtered local binary pattern (LBP) method and the contour-based masking method with a coefficient k, and (iii) the optimal use of SVM with the radial basis function (RBF) kernel to precisely identify broadleaf plants based on their distinctive features. The high performance of this k-FLBPCM method is demonstrated by experimentally attaining up to 98.63% classification accuracy at four different growth stages for all classes of the “bccr-segset” dataset.
To evaluate performance of the k-FLBPCM algorithm in real-time, a comparison analysis between our novel method (k-FLBPCM) and deep convolutional neural networks (DCNNs) is conducted on morphologically similar crops and weeds. Various DCNN models, namely VGG-16, VGG-19, ResNet50 and InceptionV3, are optimised, by fine-tuning their hyper-parameters, and tested. Based on the experimental results on the “bccr-segset” dataset collected from the laboratory and the “fieldtrip_can_weeds” dataset collected from the field under practical environments, the classification accuracies of the DCNN models and the k-FLBPCM method are almost similar. Another experiment is conducted by training the algorithms with plant images obtained at mature stages and testing them at early stages. In this case, the new k-FLBPCM method outperformed the state-of-the-art CNN models in identifying small leaf shapes of canola-radish (crop-weed) at early growth stages, with an order of magnitude lower error rates in comparison with DCNN models. Furthermore, the execution time of the k-FLBPCM method during the training and test phases was faster than the DCNN counterparts, with an identification time difference of approximately 0.224ms per image for the laboratory dataset and 0.346ms per image for the field dataset. These results demonstrate the ability of the k-FLBPCM method to rapidly detect weeds from crops of similar appearance in real time with less data, and generalize to different size plants better than the CNN-based methods.
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Cui, Chen. "Adaptive weighted local textural features for illumination, expression and occlusion invariant face recognition." University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1374782158.
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Björkeson, Felix. "Autonomous Morphometrics using Depth Cameras for Object Classification and Identification." Thesis, Linköpings universitet, Datorseende, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-95240.
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Identification of individuals has been solved with many different solutions around the world, either using biometric data or external means of verification such as id cards or RFID tags. The advantage of using biometric measurements is that they are directly tied to the individual and are usually unalterable. Acquiring dependable measurements is however challenging when the individuals are uncooperative. A dependable system should be able to deal with this and produce reliable identifications. The system proposed in this thesis can autonomously classify uncooperative specimens from depth data. The data is acquired from a depth camera mounted in an uncontrolled environment, where it was allowed to continuously record for two weeks. This requires stable data extraction and normalization algorithms to produce good representations of the specimens. Robust descriptors can therefore be extracted from each sample of a specimen and together with different classification algorithms, the system can be trained or validated. Even with as many as 138 different classes the system achieves high recognition rates. Inspired by the research field of face recognition, the best classification algorithm, the method of fisherfaces, was able to accurately recognize 99.6% of the validation samples. Followed by two variations of the method of eigenfaces, achieving recognition rates of 98.8% and 97.9%. These results affirm that the capabilities of the system are adequate for a commercial implementation.
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Guo, Y. (Yimo). "Image and video analysis by local descriptors and deformable image registration." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526201412.
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Abstract Image description plays an important role in representing inherent properties of entities and scenes in static images. Within the last few decades, it has become a fundamental issue of many practical vision tasks, such as texture classification, face recognition, material categorization, and medical image processing. The study of static image analysis can also be extended to video analysis, such as dynamic texture recognition, classification and synthesis. This thesis contributes to the research and development of image and video analysis from two aspects. In the first part of this work, two image description methods are presented to provide discriminative representations for image classification. They are designed in unsupervised (i.e., class labels of texture images are not available) and supervised (i.e., class labels of texture images are available) manner, respectively. First, a supervised model is developed to learn discriminative local patterns, which formulates the image description as an integrated three-layered model to estimate an optimal pattern subset of interest by simultaneously considering the robustness, discriminative power and representation capability of features. Second, in the case that class labels of training images are unavailable, a linear configuration model is presented to describe microscopic image structures in an unsupervised manner, which is subsequently combined together with a local descriptor: local binary pattern (LBP). This description is theoretically verified to be rotation invariant and is able to provide a discriminative complement to the conventional LBPs. In the second part of the thesis, based on static image description and deformable image registration, video analysis is studied for the applications of dynamic texture description, synthesis and recognition. First, a dynamic texture synthesis model is proposed to create a continuous and infinitely varying stream of images given a finite input video, which stitches video clips in the time domain by selecting proper matching frames and organizing them into a logical order. Second, a method for the application of facial expression recognition, which formulates the dynamic facial expression recognition problem as the construction of longitudinal atlases and groupwise image registration problem, is proposed<br>Tiivistelmä Kuvan deskriptiolla on tärkeä rooli staattisissa kuvissa esiintyvien luontaisten kokonaisuuksien ja näkymien kuvaamisessa. Viime vuosikymmeninä se on tullut perustavaa laatua olevaksi ongelmaksi monissa käytännön konenäön tehtävissä, kuten tekstuurien luokittelu, kasvojen tunnistaminen, materiaalien luokittelu ja lääketieteellisten kuvien analysointi. Staattisen kuva-analyysin tutkimusala voidaan myös laajentaa videoanalyysiin, kuten dynaamisten tekstuurien tunnistukseen, luokitteluun ja synteesiin. Tämä väitöskirjatutkimus myötävaikuttaa kuva- ja videoanalyysin tutkimukseen ja kehittymiseen kahdesta näkökulmasta. Työn ensimmäisessä osassa esitetään kaksi kuvan deskriptiomenetelmää erottelukykyisten esitystapojen luomiseksi kuvien luokitteluun. Ne suunnitellaan ohjaamattomiksi (eli tekstuurikuvien luokkien leimoja ei ole käytettävissä) tai ohjatuiksi (eli luokkien leimat ovat saatavilla). Aluksi kehitetään ohjattu malli oppimaan erottelukykyisiä paikallisia kuvioita, mikä formuloi kuvan deskriptiomenetelmän integroituna kolmikerroksisena mallina - tavoitteena estimoida optimaalinen kiinnostavien kuvioiden alijoukko ottamalla samanaikaisesti huomioon piirteiden robustisuus, erottelukyky ja esityskapasiteetti. Seuraavaksi, sellaisia tapauksia varten, joissa luokkaleimoja ei ole saatavilla, esitetään työssä lineaarinen konfiguraatiomalli kuvaamaan kuvan mikroskooppisia rakenteita ohjaamattomalla tavalla. Tätä käytetään sitten yhdessä paikallisen kuvaajan, eli local binary pattern (LBP) –operaattorin kanssa. Teoreettisella tarkastelulla osoitetaan kehitetyn kuvaajan olevan rotaatioinvariantti ja kykenevän tuottamaan erottelukykyistä, täydentävää informaatiota perinteiselle LBP-menetelmälle. Työn toisessa osassa tutkitaan videoanalyysiä, perustuen staattisen kuvan deskriptioon ja deformoituvaan kuvien rekisteröintiin – sovellusaloina dynaamisten tekstuurien kuvaaminen, synteesi ja tunnistaminen. Aluksi ehdotetaan sellainen malli dynaamisten tekstuurien synteesiin, joka luo jatkuvan ja äärettömän kuvien virran annetusta äärellisen mittaisesta videosta. Menetelmä liittää yhteen videon pätkiä aika-avaruudessa valitsemalla keskenään yhteensopivia kuvakehyksiä videosta ja järjestämällä ne loogiseen järjestykseen. Seuraavaksi työssä esitetään sellainen uusi menetelmä kasvojen ilmeiden tunnistukseen, joka formuloi dynaamisen kasvojen ilmeiden tunnistusongelman pitkittäissuuntaisten kartastojen rakentamisen ja ryhmäkohtaisen kuvien rekisteröinnin ongelmana
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Zbranek, Miroslav. "Metody detekce a rozpoznání obličeje v obrazu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219650.
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The aim of this diploma thesis is to explore methods of face detection and recognition in the picture. The method for face detection and the method for face recognition will be chosen according to literature survey. Both methods will be implemented using the OpenCV library and a program language C/C++. The result of this project is creation of graphic interface which use programmed function for face detection and recognition from a picture and also a camcorder.
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Kadlček, Filip. "Implementace obrazových klasifikátorů v FPGA." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2010. http://www.nusl.cz/ntk/nusl-237091.
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The thesis deals with image classifiers and their implementation using FPGA technology. There are discussed weak and strong classifiers in the work. As an example of strong classifiers, the AdaBoost algorithm is described. In the case of weak classifiers, basic types of feature classifiers are shown, including Haar and Gabor wavelets. The rest of work is primarily focused on LBP, LRP and LR classifiers, which are well suitable for efficient implementation in FPGAs. With these classifiers is designed pseudo-parallel architecture. Process of classifications is divided on software and hardware parts. The thesis deals with hardware part of classifications. The designed classifier is very fast and produces results of classification every clock cycle.
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Sierra, Brandon Luis. "COMPARING AND IMPROVING FACIAL RECOGNITION METHOD." CSUSB ScholarWorks, 2017. https://scholarworks.lib.csusb.edu/etd/575.
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Facial recognition is the process in which a sample face can be correctly identified by a machine amongst a group of different faces. With the never-ending need for improvement in the fields of security, surveillance, and identification, facial recognition is becoming increasingly important. Considering this importance, it is imperative that the correct faces are recognized and the error rate is as minimal as possible. Despite the wide variety of current methods for facial recognition, there is no clear cut best method. This project reviews and examines three different methods for facial recognition: Eigenfaces, Fisherfaces, and Local Binary Patterns to determine which method has the highest accuracy of prediction rate. The three methods are reviewed and then compared via experiments. OpenCV, CMake, and Visual Studios were used as tools to conduct experiments. Analysis were conducted to identify which method has the highest accuracy of prediction rate with various experimental factors. By feeding a number of sample images of different people which serve as experimental subjects. The machine is first trained to generate features for each person among the testing subjects. Then, a new image was tested against the “learned” data and be labeled as one of the subjects. With experimental data analysis, the Eigenfaces method was determined to have the highest prediction rate of the three algorithms tested. The Local Binary Pattern Histogram (LBP) was found to have the lowest prediction rate. Finally, LBP was selected for the algorithm improvement. In this project, LBP was improved by identifying the most significant regions of the histograms for each person in training time. The weights of each region are assigned depending on the gray scale contrast. At recognition time, given a new face, different weights are assigned to different regions to increase prediction rate and also speed up the real time recognition. The experimental results confirmed the performance improvement.
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Huang, X. (Xiaohua). "Methods for facial expression recognition with applications in challenging situations." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526206561.
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Abstract In recent years, facial expression recognition has become a useful scheme for computers to affectively understand the emotional state of human beings. Facial representation and facial expression recognition under unconstrained environments have been two critical issues for facial expression recognition systems. This thesis contributes to the research and development of facial expression recognition systems from two aspects: first, feature extraction for facial expression recognition, and second, applications to challenging conditions. Spatial and temporal feature extraction methods are introduced to provide effective and discriminative features for facial expression recognition. The thesis begins with a spatial feature extraction method. This descriptor exploits magnitude while it improves local quantized pattern using improved vector quantization. It also makes the statistical patterns domain-adaptive and compact. Then, the thesis discusses two spatiotemporal feature extraction methods. The first method uses monogenic signal analysis as a preprocessing stage and extracts spatiotemporal features using local binary pattern. The second method extracts sparse spatiotemporal features using sparse cuboids and spatiotemporal local binary pattern. Both methods increase the discriminative capability of local binary pattern in the temporal domain. Based on feature extraction methods, three practical conditions, including illumination variations, facial occlusion and pose changes, are studied for the applications of facial expression recognition. First, with near-infrared imaging technique, a discriminative component-based single feature descriptor is proposed to achieve a high degree of robustness and stability to illumination variations. Second, occlusion detection is proposed to dynamically detect the occluded face regions. A novel system is further designed for handling effectively facial occlusion. Lastly, multi-view discriminative neighbor preserving embedding is developed to deal with pose change, which formulates multi-view facial expression recognition as a generalized eigenvalue problem. Experimental results on publicly available databases show that the effectiveness of the proposed approaches for the applications of facial expression recognition<br>Tiivistelmä Kasvonilmeiden tunnistamisesta on viime vuosina tullut tietokoneille hyödyllinen tapa ymmärtää affektiivisesti ihmisen tunnetilaa. Kasvojen esittäminen ja kasvonilmeiden tunnistaminen rajoittamattomissa ympäristöissä ovat olleet kaksi kriittistä ongelmaa kasvonilmeitä tunnistavien järjestelmien kannalta. Tämä väitöskirjatutkimus myötävaikuttaa kasvonilmeitä tunnistavien järjestelmien tutkimukseen ja kehittymiseen kahdesta näkökulmasta: piirteiden irrottamisesta kasvonilmeiden tunnistamista varten ja kasvonilmeiden tunnistamisesta haastavissa olosuhteissa. Työssä esitellään spatiaalisia ja temporaalisia piirteenirrotusmenetelmiä, jotka tuottavat tehokkaita ja erottelukykyisiä piirteitä kasvonilmeiden tunnistamiseen. Ensimmäisenä työssä esitellään spatiaalinen piirteenirrotusmenetelmä, joka parantaa paikallisia kvantisoituja piirteitä käyttämällä parannettua vektorikvantisointia. Menetelmä tekee myös tilastollisista malleista monikäyttöisiä ja tiiviitä. Seuraavaksi työssä esitellään kaksi spatiotemporaalista piirteenirrotusmenetelmää. Ensimmäinen näistä käyttää esikäsittelynä monogeenistä signaalianalyysiä ja irrottaa spatiotemporaaliset piirteet paikallisia binäärikuvioita käyttäen. Toinen menetelmä irrottaa harvoja spatiotemporaalisia piirteitä käyttäen harvoja kuusitahokkaita ja spatiotemporaalisia paikallisia binäärikuvioita. Molemmat menetelmät parantavat paikallisten binärikuvioiden erottelukykyä ajallisessa ulottuvuudessa. Piirteenirrotusmenetelmien pohjalta työssä tutkitaan kasvonilmeiden tunnistusta kolmessa käytännön olosuhteessa, joissa esiintyy vaihtelua valaistuksessa, okkluusiossa ja pään asennossa. Ensiksi ehdotetaan lähi-infrapuna kuvantamista hyödyntävää diskriminatiivistä komponenttipohjaista yhden piirteen kuvausta, jolla saavutetaan korkea suoritusvarmuus valaistuksen vaihtelun suhteen. Toiseksi ehdotetaan menetelmä okkluusion havainnointiin, jolla dynaamisesti havaitaan peittyneet kasvon alueet. Uudenlainen menetelmä on kehitetty käsittelemään kasvojen okkluusio tehokkaasti. Viimeiseksi työssä on kehitetty moninäkymäinen diskriminatiivisen naapuruston säilyttävään upottamiseen pohjautuva menetelmä käsittelemään pään asennon vaihtelut. Menetelmä kuvaa moninäkymäisen kasvonilmeiden tunnistamisen yleistettynä ominaisarvohajotelmana. Kokeelliset tulokset julkisilla tietokannoilla osoittavat tässä työssä ehdotetut menetelmät suorituskykyisiksi kasvonilmeiden tunnistamisessa
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Kremličková, Lenka. "Hodnocení viability kardiomyocytů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316800.
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The aim of this diploma thesis is to get acquainted with the properties of image data and the principle of their capture. Literary research on methods of image segmentation in the area of cardiac tissue imaging and, last but not least, efforts to find methods for classification of dead cardiomyocytes and analysis of their viability. Dead cardiomyocytes were analyzed for their shape and similarity to the template created as a mean of dead cells. Another approach was the application of the method based on local binary characters and the computation of symptoms from a simple and associated histogram.
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ROCHA, Simara Vieira da. "Diferenciação do padrão de malignidade e benignidade de massas em imagens de mamografias usando padrões locais binários, geoestatística e índice de diversidade." Universidade Federal do Maranhão, 2014. http://tedebc.ufma.br:8080/jspui/handle/tede/1822.
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Previous issue date: 2014-05-22<br>Breast cancer is the second most frequent type of cancer in the world, being more common among women, and representing 22% of the new cases every year. A precocious diagnosis improves the chances of a successful treatment. Mammography is one of the best ways to precocious detection of non-palpable tumor that could lead to a breast cancer. However, it is well known that this exam's sensibility may vary a lot. This is due to factors such as: the specialist's experience, patient's age and the quality of the exam image. The use of Image Processing and Machine Learning techniques has becoming a strong contribution to the specialist diagnosis task. Thes thesis proposes a methodology to discriminate patterns of malignancy and benignity of masses in mammographic images using texture analysis and machine learning. For this purpose, the methodology combines structural and statistical approaches for the analysis of texture regions extracted from mammograms. Furthermore, this research extends the concept of Diversity Index through the use of species co-occurrence information in order to increase the efficiency of extraction of texture features. The techniques used are Local Binary Pattern, Ripley's K function and diversity indexes (Shannon, Mcintosh, Simpson, Gleason and Menhinick indexes). The extracted texture is classified using a Support Vector Machine into benign and malignant classes. The best results obrained with Ripley's K function were 92,20% of accuracy, 92,96% of sensibility, 91,26% of specificity, 10.63 of likelihood positive ratio, 0,07 of likelihood negative ratio and an area under ROC curve Az of 0,92.<br>O câncer de mama é o segundo tipo de câncer mais frequente no mundo, sendo mais comum entre as mulheres, respondendo por 22% dos casos novos a cada ano. Quanto mais precocemente for diagnosticado, maiores serão as chances de se realizar um tratamento bem sucedido. A mamogra fia é uma das formas de detectar os tumores não palpáveis que causam câncer de mama. Todavia, sabe-se que a sensibilidade desse exame pode variar bastante, devido a fatores como: a experiência do especialista, a idade do paciente e a qualidade das imagens obtidas no exame. O uso de técnicas de Processamento de Imagens e Aprendizagem de Máquina tem contribuído, cada vez mais, para auxiliar os especialistas na realização de diagnósticos mais precisos. Esta tese propõe uma metodologia para discriminar padrões de malignidade e benignidade de massas em imagens de mamogra fias, utilizando análise de textura e aprendizado de máquina. Para tanto, a metodologia combina as abordagens estrutural e estatística para a análise de textura de regiões extraídas das mamogra fias. Além disso, esta pesquisa amplia o conceito de Índice de Diversidade, através do uso da informação de co-ocorrência de espécies, com o propósito de aumentar a e ficiência da extração de características de textura. Assim, são usadas as técnicas de Local Binary Pattern, Função K de Ripley e os Índices de Shannon, Mcintosh, Simpson, Gleason e de Menhinick. Por fi m, a textura extraída e classi ficada utilizando a Máquina de Vetores de Suporte, visando diferenciar as massas malignas das benignas. O melhor resultado foi obtido usando a função K de Ripley com 92,20% de acurácia, 92,96% de sensibilidade, 91,26% de especi cidade, 10,63 de razão de probabilidade positiva, 0,07% de razão de probabilidade negativa e uma área sob a curva ROC (Az) de 0,92.
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Turtinen, M. (Markus). "Learning and recognizing texture characteristics using local binary patterns." Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514285028.
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Abstract
Texture plays an important role in numerous computer vision applications. Many methods for describing and analyzing of textured surfaces have been proposed. Variations in the appearance of texture caused by changing illumination and imaging conditions, for example, set high requirements on different analysis methods. In addition, real-world applications tend to produce a great deal of complex texture data to be processed that should be handled effectively in order to be exploited.
A local binary pattern (LBP) operator offers an efficient way of analyzing textures. It has a simple theory and combines properties of structural and statistical texture analysis methods. LBP is invariant against monotonic gray-scale variations and has also extensions to rotation invariant texture analysis.
Analysis of real-world texture data is typically very laborious and time consuming. Often there is no ground truth or other prior knowledge of the data available, and important properties of the textures must be learned from the images. This is a very challenging task in texture analysis.
In this thesis, methods for learning and recognizing texture categories using local binary pattern features are proposed. Unsupervised clustering and dimensionality reduction methods combined to visualization provide useful tools for analyzing texture data. Uncovering the data structures is done in an unsupervised fashion, based only on texture features, and no prior knowledge of the data, for example texture classes, is required. In this thesis, non-linear dimensionality reduction, data clustering and visualization are used for building a labeled training set for a classifier, and for studying the performance of the features.
The thesis also proposes a multi-class approach to learning and labeling part based texture appearance models to be used in scene texture recognition using only little human interaction. Also a semiautomatic approach to learning texture appearance models for view based texture classification is proposed.
The goal of texture characterization is often to classify textures into different categories. In this thesis, two texture classification systems suitable for different applications are proposed. First, a discriminative classifier that combines local and contextual texture information of the image in scene recognition is proposed. Secondly, a real-time capable texture classifier with a self-intuitive user interface to be used in industrial texture classification is proposed.
Two challenging real-world texture analysis applications are used to study the performance and usefulness of the proposed methods. The first one is visual paper analysis which aims to characterize paper quality based on texture properties. The second application is outdoor scene image analysis where texture information is used to recognize different regions in the scenes.
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Kellokumpu, V. P. (Vili-Petteri). "Vision-based human motion description and recognition." Doctoral thesis, Oulun yliopisto, 2011. http://urn.fi/urn:isbn:9789514296758.
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Abstract This thesis investigates vision based description and recognition of human movements. Automated vision based human motion analysis is a fundamental technology for creating video based human computer interaction systems. Because of its wide range of potential applications, the topic has become an active area of research in the computer vision community. This thesis proposes the use of low level description of dynamics for human movement description and recognition. Two groups of approaches are developed: first, texture based methods that extract dynamic features for human movement description, and second, a framework that considers ballistic dynamics for human movement segmentation and recognition. Two texture based descriptions for human movement analysis are introduced. The first method uses the temporal templates as a preprocessing stage and extracts a motion description using local binary pattern texture features. This approach is then extended to a spatiotemporal space and a dynamic texture based method that uses local binary patterns from three orthogonal planes is proposed. The method needs no accurate segmentation of silhouettes, rather, it is designed to work on image data. The dynamic texture based description is also applied to gait recognition. The proposed descriptions have been experimentally validated on publicly available databases. Psychological studies on human movement indicate that common movements such as reaching and striking are ballistic by nature. Based on the psychological observations this thesis considers the segmentation and recognition of ballistic movements using low level motion features. Experimental results on motion capture and video data show the effectiveness of the method<br>Tiivistelmä Tässä väitöskirjassa tutkitaan ihmisen liikkeen kuvaamista ja tunnistamista konenäkömenetelmillä. Ihmisen liikkeen automaattinen analyysi on keskeinen teknologia luotaessa videopohjaisia järjestelmiä ihmisen ja koneen vuorovaikutukseen. Laajojen sovellusmahdollisuuksiensa myötä aiheesta on tullut aktiivinen tutkimusalue konenäön tutkimuksen piirissä. Väitöskirjassa tutkitaan matalan tason piirteiden käyttöä ihmisen liikkeen dynaamiikan kuvaamiseen ja tunnistamiseen. Työssä esitetään kaksi tekstuuripohjaista mentelmää ihmisen liikkeen kuvaamiseen ja viitekehys ballististen liikkeiden segmentointiin ja tunnistamiseen. Työssä esitetään kaksi tekstuuripohjaista menetelmää ihmisen liikkeen analysointiin. Ensimmäinen menetelmä käyttää esikäsittelynä ajallisia kuvamalleja ja kuvaa mallit paikallisilla binäärikuvioilla. Menetelmä laajennetaan myös tila-aika-avaruuteen. Dynaamiseen tekstuuriin perustuva menetelmä irroittaa paikalliset binäärikuviot tila-aika-avaruuden kolmelta ortogonaaliselta tasolta. Menetelmä ei vaadi ihmisen siluetin tarkkaa segmentointia kuvista, koska se on suunniteltu toimimaan suoraan kuvatiedon perusteella. Dynaamiseen tekstuuriin pohjautuvaa menetelmää sovelletaan myös henkilön tunnistamiseen kävelytyylin perusteella. Esitetyt menetelmät on kokeellisesti vahvistettu yleisesti käytetyillä ja julkisesti saatavilla olevilla tietokannoilla. Psykologiset tutkimukset ihmisen liikkumisesta osoittavat, että yleiset liikkeet, kuten kurkoittaminen ja iskeminen, ovat luonteeltaan ballistisia. Tässä työssä tarkastellaan ihmisen liikkeen ajallista segmentointia ja tunnistamista matalan tason liikepiirteistä hyödyntäen psykologisia havaintoja. Kokeelliset tulokset liikkeenkaappaus ja video aineistolla osoittavat menetelmän toimivan hyvin
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Jebelli, Ali. "Design of an Autonomous Underwater Vehicle with Vision Capabilities." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35358.
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In the past decade, the design and manufacturing of intelligent multipurpose underwater
vehicles has increased significantly. In the wide range of studies conducted in this field, the
flexibility and autonomy of these devices with respect to their intended performance had
been widely investigated.
This work is related to the design and manufacturing of a small and lightweight
autonomous underwater vehicle (AUV) with vision capabilities allowing detecting and
contouring obstacles.
It is indeed an exciting challenge to build a small and light submarine AUV, while making
tradeoffs between performance and minimum available space as well as energy
consumption. In fact, due to the ever-increasing in equipment complexity and performance,
designers of AUVs are facing the issues of limited size and energy consumption.
By using a pair of thrusters capable to rotate 360o on their axis and implementing a mass
shifter with a control loop inside the vehicle, this later can efficiently adapt its depth and
direction with minimal energy consumption. A prototype was fabricated and successfully
tested in real operating conditions (in both pool and ocean). It includes the design and
embedding of accurate custom multi-purpose sensors for multi-task operation as well as an
enhanced coordinated system between a high-speed processor and accustomed
electrical/mechanical parts of the vehicle, to allow automatic controlling its movements.
Furthermore, an efficient tracking system was implemented to automatically detect and
bypass obstacles. Then, fuzzy-based controllers were coupled to the main AUV processor
system to provide the best commands to safely get around obstacles with minimum energy
consumption. The fabricated prototype was able to work for a period of three hours with
object tracking options and five hours in a safe environment, at a speed of 0.6 m/s at a
depth of 8 m.
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Babinec, Adam. "Monitorování dopravy z leteckých videí." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2015. http://www.nusl.cz/ntk/nusl-264938.
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This thesis proposes a system for extraction of vehicle trajectories from aerial video data for traffic analysis. The system is designed to analyse video sequence of a single traffic scene captured by an action camera mounted on an arbitrary UAV flying at the altitudes of approximately 150 m. Each video frame is geo-registered using visual correspondence of extracted ORB features. For the detection of vehicles, MB-LBP classifier cascade is deployed, with additional step of pre-filtering of detection candidates based on movement and scene context. Multi-object tracking is achieved by Bayesian bootstrap filter with an aid of the detection algorithm. The performance of the system was evaluated on three extensively annotated datasets. The results show that on the average, 92% of all extracted trajectories are corresponding to the reality. The system is already being used in the research to aid the process of design and analysis of road infrastructures.
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Oliveira, Alex Paulo Alves de. "Um método para classificação de imagens de madeira usando Local Binary Patterns." Universidade Federal de Pernambuco, 2013. https://repositorio.ufpe.br/handle/123456789/11469.
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Previous issue date: 2013-03-12<br>O tráfico ilegal de madeiras é um problema no Brasil, percebido com mais frequência nas
alfândegas da Amazônia. O objetivo desse trabalho é o desenvolvimento de um método para
classificação de imagens de madeira. As imagens, usadas nessa pesquisa, foram fornecidas
pela Embrapa e pelo VRI (UFPR).
Para o classificador criado, cada imagem é representada pelo histograma resultante da aplicação
do operador LBP (Local Binary Patterns). A classificação desenvolvida tem como base
o aprendizado baseado em instâncias, utilizando o algoritmo K-NN (K-Nearest Neighbor).
O aumento na quantidade de amostras, disponíveis para um mesmo teste, foi suficiente
para tornar mais evidentes as diferenças de performance entre as diversos cenários elaborados.
Foram consideradas duas abordagens de Cross-Validation: O K-Fold Cross-Validation e o
Leave-One-Out Cross-Validation. Quase sempre, quando o Leave-One-Out Cross-Validation
foi adotado, os resultados apresentam uma acurácia melhor em relação à outra abordagem.
Neste trabalho, também foram realizados alguns testes para mensurar a robustez em relação
ao ruído, e, ficou constatado que o ruído pode influenciar os resultados da classificação.
A normalização influenciou os resultados obtidos pelo classificador, entretanto, dentre as
variáveis consideradas, essa foi a menos influente.
Foi possível perceber que a métrica adotada, para mensurar distâncias, influencia elementos
importantes: o índice de acertos e a velocidade de resposta (processamento computacional
exigido). O Kullback Leibler Divergence foi a métrica que apresentou melhores resultados.
O classificador construído neste trabalho se mostrou igualmente eficiente para bases com
imagens homogênias (com mesma dimensão e formato) e heterogênias;
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Lease, Basil Andy. "Weed/Plant Classification Using Evolutionary Optimised Ensemble Based On Local Binary Patterns." Thesis, Curtin University, 2022. http://hdl.handle.net/20.500.11937/88106.
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This thesis presents a novel pixel-level weed classification through rotation-invariant uniform local binary pattern (LBP) features for precision weed control. Based on two-level optimisation structure; First, Genetic Algorithm (GA) optimisation to select the best rotation-invariant uniform LBP configurations; Second, Covariance Matrix Adaptation Evolution Strategy (CMA-ES) in the Neural Network (NN) ensemble to select the best combinations of voting weights of the predicted outcome for each classifier. The model obtained 87.9% accuracy in CWFID public benchmark.
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Sivri, Erdal. "Shape Descriptors Based On Intersection Consistency And Global Binary Patterns." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614780/index.pdf.
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Shape description is an important problem in computer vision because most vision tasks that require comparing or matching visual entities rely on shape descriptors. In this thesis, two novel shape descriptors are proposed, namely Intersection Consistency Histogram (ICH) and Global Binary Patterns (GBP). The former is based on a local regularity measure called Intersection Consistency (IC), which determines whether edge pixels in an image patch point towards the center or not. The second method, called Global Binary Patterns, represents the shape in binary along horizontal, vertical, diagonal or principal directions. These two methods are extensively analyzed on several databases, and retrieval and running time performances are presented. Moreover, these methods are compared with methods such as Shape Context, Histograms of Oriented Gradients, Local Binary Patterns and Fourier Descriptors. We report that our descriptors perform comparable to these methods.
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Hussain, Sibt Ul. "Apprentissage machine pour la détection des objets." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00722632.
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Le but de cette thèse est de développer des méthodes pratiques plus performantes pour la détection d'instances de classes d'objets de la vie quotidienne dans les images. Nous présentons une famille de détecteurs qui incorporent trois types d'indices visuelles performantes - histogrammes de gradients orientés (Histograms of Oriented Gradients, HOG), motifs locaux binaires (Local Binary Patterns, LBP) et motifs locaux ternaires (Local Ternary Patterns, LTP) - dans des méthodes de discrimination efficaces de type machine à vecteur de support latent (Latent SVM), sous deux régimes de réduction de dimension - moindres carrées partielles (Partial Least Squares, PLS) et sélection de variables par élagage de poids SVM (SVM Weight Truncation). Sur plusieurs jeux de données importantes, notamment ceux du PASCAL VOC2006 et VOC2007, INRIA Person et ETH Zurich, nous démontrons que nos méthodes améliorent l'état de l'art du domaine. Nos contributions principales sont : Nous étudions l'indice visuelle LTP pour la détection d'objets. Nous démontrons que sa performance est globalement mieux que celle des indices bien établies HOG et LBP parce qu'elle permet d'encoder à la fois la texture locale de l'objet et sa forme globale, tout en étant résistante aux variations d'éclairage. Grâce à ces atouts, LTP fonctionne aussi bien pour les classes qui sont caractérisées principalement par leurs structures que pour celles qui sont caractérisées par leurs textures. En plus, nous démontrons que les indices HOG, LBP et LTP sont bien complémentaires, de sorte qu'un jeux d'indices étendu qui intègre tous les trois améliore encore la performance. Les jeux d'indices visuelles performantes étant de dimension assez élevée, nous proposons deux méthodes de réduction de dimension afin d'améliorer leur vitesse et réduire leur utilisation de mémoire. La première, basée sur la projection moindres carrés partielles, diminue significativement le temps de formation des détecteurs linéaires, sans réduction de précision ni perte de vitesse d'exécution. La seconde, fondée sur la sélection de variables par l'élagage des poids du SVM, nous permet de réduire le nombre d'indices actives par un ordre de grandeur avec une réduction minime, voire même une petite augmentation, de la précision du détecteur. Malgré sa simplicité, cette méthode de sélection de variables surpasse toutes les autres approches que nous avons mis à l'essai.
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Khan, Rizwan Ahmed. "Détection des émotions à partir de vidéos dans un environnement non contrôlé." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10227/document.
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Dans notre communication quotidienne avec les autres, nous avons autant de considération pour l’interlocuteur lui-même que pour l’information transmise. En permanence coexistent en effet deux modes de transmission : le verbal et le non-verbal. Sur ce dernier thème intervient principalement l’expression faciale avec laquelle l’interlocuteur peut révéler d’autres émotions et intentions. Habituellement, un processus de reconnaissance d’émotions faciales repose sur 3 étapes : le suivi du visage, l’extraction de caractéristiques puis la classification de l’expression faciale. Pour obtenir un processus robuste apte à fournir des résultats fiables et exploitables, il est primordial d’extraire des caractéristiques avec de forts pouvoirs discriminants (selon les zones du visage concernées). Les avancées récentes de l’état de l’art ont conduit aujourd’hui à diverses approches souvent bridées par des temps de traitement trop couteux compte-tenu de l’extraction de descripteurs sur le visage complet ou sur des heuristiques mathématiques et/ou géométriques.En fait, aucune réponse bio-inspirée n’exploite la perception humaine dans cette tâche qu’elle opère pourtant régulièrement. Au cours de ces travaux de thèse, la base de notre approche fut ainsi de singer le modèle visuel pour focaliser le calcul de nos descripteurs sur les seules régions du visage essentielles pour la reconnaissance d’émotions. Cette approche nous a permis de concevoir un processus plus naturel basé sur ces seules régions émergentes au regard de la perception humaine. Ce manuscrit présente les différentes méthodologies bio-inspirées mises en place pour aboutir à des résultats qui améliorent généralement l’état de l’art sur les bases de référence. Ensuite, compte-tenu du fait qu’elles se focalisent sur les seules parties émergentes du visage, elles améliorent les temps de calcul et la complexité des algorithmes mis en jeu conduisant à une utilisation possible pour des applications temps réel<br>Communication in any form i.e. verbal or non-verbal is vital to complete various daily routine tasks and plays a significant role inlife. Facial expression is the most effective form of non-verbal communication and it provides a clue about emotional state, mindset and intention. Generally automatic facial expression recognition framework consists of three step: face tracking, feature extraction and expression classification. In order to built robust facial expression recognition framework that is capable of producing reliable results, it is necessary to extract features (from the appropriate facial regions) that have strong discriminative abilities. Recently different methods for automatic facial expression recognition have been proposed, but invariably they all are computationally expensive and spend computational time on whole face image or divides the facial image based on some mathematical or geometrical heuristic for features extraction. None of them take inspiration from the human visual system in completing the same task. In this research thesis we took inspiration from the human visual system in order to find from where (facial region) to extract features. We argue that the task of expression analysis and recognition could be done in more conducive manner, if only some regions are selected for further processing (i.e.salient regions) as it happens in human visual system. In this research thesis we have proposed different frameworks for automatic recognition of expressions, all getting inspiration from the human vision. Every subsequently proposed addresses the shortcomings of the previously proposed framework. Our proposed frameworks in general, achieve results that exceeds state-of-the-artmethods for expression recognition. Secondly, they are computationally efficient and simple as they process only perceptually salient region(s) of face for feature extraction. By processing only perceptually salient region(s) of the face, reduction in feature vector dimensionality and reduction in computational time for feature extraction is achieved. Thus making them suitable for real-time applications
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Zhu, Chao. "Effective and efficient visual description based on local binary patterns and gradient distribution for object recognition." Phd thesis, Ecole Centrale de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00755644.
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Cette thèse est consacrée au problème de la reconnaissance visuelle des objets basé sur l'ordinateur, qui est devenue un sujet de recherche très populaire et important ces dernières années grâce à ses nombreuses applications comme l'indexation et la recherche d'image et de vidéo , le contrôle d'accès de sécurité, la surveillance vidéo, etc. Malgré beaucoup d'efforts et de progrès qui ont été fait pendant les dernières années, il reste un problème ouvert et est encore considéré comme l'un des problèmes les plus difficiles dans la communauté de vision par ordinateur, principalement en raison des similarités entre les classes et des variations intra-classe comme occlusion, clutter de fond, les changements de point de vue, pose, l'échelle et l'éclairage. Les approches populaires d'aujourd'hui pour la reconnaissance des objets sont basé sur les descripteurs et les classiffieurs, ce qui généralement extrait des descripteurs visuelles dans les images et les vidéos d'abord, et puis effectue la classification en utilisant des algorithmes d'apprentissage automatique sur la base des caractéristiques extraites. Ainsi, il est important de concevoir une bonne description visuelle, qui devrait être à la fois discriminatoire et efficace à calcul, tout en possédant certaines propriétés de robustesse contre les variations mentionnées précédemment. Dans ce contexte, l'objectif de cette thèse est de proposer des contributions novatrices pour la tâche de la reconnaissance visuelle des objets, en particulier de présenter plusieurs nouveaux descripteurs visuelles qui représentent effectivement et efficacement le contenu visuel d'image et de vidéo pour la reconnaissance des objets. Les descripteurs proposés ont l'intention de capturer l'information visuelle sous aspects différents. Tout d'abord, nous proposons six caractéristiques LBP couleurs de multi-échelle pour traiter les défauts principaux du LBP original, c'est-à-dire, le déffcit d'information de couleur et la sensibilité aux variations des conditions d'éclairage non-monotoniques. En étendant le LBP original à la forme de multi-échelle dans les différents espaces de couleur, les caractéristiques proposées non seulement ont plus de puissance discriminante par l'obtention de plus d'information locale, mais possèdent également certaines propriétés d'invariance aux différentes variations des conditions d'éclairage. En plus, leurs performances sont encore améliorées en appliquant une stratégie de l'image division grossière à fine pour calculer les caractéristiques proposées dans les blocs d'image afin de coder l'information spatiale des structures de texture. Les caractéristiques proposées capturent la distribution mondiale de l'information de texture dans les images. Deuxièmement, nous proposons une nouvelle méthode pour réduire la dimensionnalité du LBP appelée la combinaison orthogonale de LBP (OC-LBP). Elle est adoptée pour construire un nouveau descripteur local basé sur la distribution en suivant une manière similaire à SIFT. Notre objectif est de construire un descripteur local plus efficace en remplaçant l'information de gradient coûteux par des patterns de texture locales dans le régime du SIFT. Comme l'extension de notre première contribution, nous étendons également le descripteur OC-LBP aux différents espaces de couleur et proposons six descripteurs OC-LBP couleurs pour améliorer la puissance discriminante et la propriété d'invariance photométrique du descripteur basé sur l'intensité. Les descripteurs proposés capturent la distribution locale de l'information de texture dans les images. Troisièmement, nous introduisons DAISY, un nouveau descripteur local rapide basé sur la distribution de gradient, dans le domaine de la reconnaissance visuelle des objets. [...]
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Kaipala, J. (Jukka). "Automatic segmentation of bone tissue from computed tomography using a volumetric local binary patterns based method." Master's thesis, University of Oulu, 2018. http://urn.fi/URN:NBN:fi:oulu-201802101221.
Full textAbstract:
Segmentation of scanned tissue volumes of three-dimensional (3D) computed tomography (CT) images often involves—at least partially—some manual process, as there is no standardized automatic method. There is a need to develop fully automatic approaches, not only to improve the objectivity of the task, but also to increase the overall speed of the segmentation process. Here we extend a 3D local binary patterns (LBP) based trabecular bone segmentation method with adaptive local thresholding and additional segmentation parameters to make it more robust yet still perform adequately when compared to traditional user-assisted segmentation. We estimate parameters for the new automated adaptive multiscale LBP-based 3D segmentation method (AMLM) in our experimental setting, and have two micro-CT (μCT) scanned bovine trabecular bone tissue volumes segmented by both the AMLM and two experienced users. Comparison of the results shows superior performance of the AMLM suggesting the strong potential for this solution to perform automatic bone segmentation<br>Skannattujen kudosrakenteiden segmentointi kolmiulotteisista (3D) tomografiakuvista tehdään usein ainakin osittain manuaalisesti, sillä standardoitua automaattista menetelmää ei ole. Täysin automatisoitujen lähestymistapojen kehitys on tarpeen, sillä se parantaisi sekä segmentoinnin objektiivisuutta että sen kokonaisnopeutta. Tässä työssä laajennamme automatisoitua local binary patterns (LBP) -perustaista trabekulaarisen luun 3D-segmentointimenetelmää adaptiivisella paikallisella kynnystyksellä ja segmentoinnin lisäparametreilla tavoitteenamme vahvistaa menetelmää mutta säilyttää silti riittävä suorituskyky verrattuna perinteiseen käyttäjäavusteiseen segmentointiin. Arvioimme koejärjestelyssämme parametrit uudelle automatisoidulle adaptiiviselle moniasteikkoiselle LBP-pohjaiselle 3Dsegmentointimenetelmälle (AMLM), ja teetämme sekä AMLM:n avulla että kahden kokeneen käyttäjän toimesta binäärisegmentoinnit kahdelle mikrotietokonetomografialla (μTT) tuotetulle kuvalle naudan trabekulaarisesta luukudoksesta. Tulosten vertailu osoittaa AMLM:n suorituskyvyltään selkeästi paremmaksi, mikä antaa vahvan viitteen tämän menetelmän soveltuvuudesta automatisoituun luusegmentointiin
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Novotný, Adam. "Texturní analýza vrstvy nervových vláken na snímcích sítnice." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218649.
Full textAbstract:
This work describes completely new approach to detection of retinal nerve fibre layer (RNFL) loss in colour fundus images. Such RNFL losses indicate eye glaucoma illness and an early diagnosis of RNFL changes is very important for successful treatment. Method is presented with the purpose of supporting glaucoma diagnosis in ophthalmology. The proposed textural analysis method utilizes local binary patterns (LBP). This approach is characterized especially by computational simplicity and insensitivity to monotonic changes of illumination. Image histograms of LBP distributions are used to gain several textural features aimed to classify healthy or glaucomatous tissue of the retina. The method was experimentally tested using fundus images of glaucomatous patients with focal RNFL loss. The results show that the proposed method can be used in order to supporting diagnosis of glaucoma with satisfactory efficiency.
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Deaney, Mogammat Waleed. "A Comparison of Machine Learning Techniques for Facial Expression Recognition." University of the Western Cape, 2018. http://hdl.handle.net/11394/6412.
Full textAbstract:
Magister Scientiae - MSc (Computer Science)<br>A machine translation system that can convert South African Sign Language (SASL)
video to audio or text and vice versa would be bene cial to people who use SASL to
communicate. Five fundamental parameters are associated with sign language gestures,
these are: hand location; hand orientation; hand shape; hand movement and facial
expressions.
The aim of this research is to recognise facial expressions and to compare both feature
descriptors and machine learning techniques. This research used the Design Science
Research (DSR) methodology. A DSR artefact was built which consisted of two phases.
The rst phase compared local binary patterns (LBP), compound local binary patterns
(CLBP) and histogram of oriented gradients (HOG) using support vector machines
(SVM). The second phase compared the SVM to arti cial neural networks (ANN) and
random forests (RF) using the most promising feature descriptor|HOG|from the rst
phase. The performance was evaluated in terms of accuracy, robustness to classes,
robustness to subjects and ability to generalise on both the Binghamton University 3D
facial expression (BU-3DFE) and Cohn Kanade (CK) datasets. The evaluation rst
phase showed HOG to be the best feature descriptor followed by CLBP and LBP. The
second showed ANN to be the best choice of machine learning technique closely followed
by the SVM and RF.
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Azarmehr, Ramin. "Real-time Embedded Age and Gender Classification in Unconstrained Video." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32463.
Full textAbstract:
Recently, automatic demographic classification has found its way into embedded applications such as targeted advertising in mobile devices, and in-car warning systems for elderly drivers. In this thesis, we present a complete framework for video-based gender classification and age estimation which can perform accurately on embedded systems in real-time and under unconstrained conditions. We propose a segmental dimensionality reduction technique utilizing Enhanced Discriminant Analysis (EDA) to minimize the memory and computational requirements, and enable the implementation of these classifiers for resource-limited embedded systems which otherwise is not achievable using existing resource-intensive approaches. On a multi-resolution feature vector we have achieved up to 99.5% compression ratio for training data storage, and a maximum performance of 20 frames per second on an embedded Android platform. Also, we introduce several novel improvements such as face alignment using the nose, and an illumination normalization method for unconstrained environments using bilateral filtering. These improvements could help to suppress the textural noise, normalize the skin color, and rectify the face localization errors. A non-linear Support Vector Machine (SVM) classifier along with a discriminative demography-based classification strategy is exploited to improve both accuracy and performance of classification. We have performed several cross-database evaluations on different controlled and uncontrolled databases to assess the generalization capability of the classifiers. Our experiments demonstrated competitive accuracies compared to the resource-demanding state-of-the-art approaches.
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Faula, Yannick. "Extraction de caractéristiques sur des images acquises en contexte mobile : Application à la reconnaissance de défauts sur ouvrages d’art." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI077.
Full textAbstract:
Le réseau ferroviaire français dispose d’une infrastructure de grande ampleur qui se compose de nombreux ouvrages d’art. Ces derniers subissent les dégradations du temps et du trafic et font donc l’objet d’une surveillance périodique pour détecter l’apparition de défauts. Aujourd’hui, cette inspection se fait en grande partie, visuellement par des opérateurs experts. Plusieurs entreprises testent de nouveaux vecteurs d’acquisition photo comme le drone, destinés à la surveillance des ouvrages de génie civil. Dans cette thèse, l’objectif principal est de développer un système capable de détecter, localiser et enregistrer d’éventuels défauts de l’ouvrage. Un grand défi est de détecter des défauts sous-pixels comme les fissures en temps réel pour améliorer l’acquisition. Pour cela, une analyse par seuillage local a été conçue pour traiter de grandes images. Cette analyse permet d’extraire des points d’intérêts (Points FLASH: Fast Local Analysis by threSHolding) où une ligne droite peut se faufiler. La mise en relation intelligente de ces points permet de détecter et localiser les fissures fines. Les résultats de détection de fissures de surfaces altérées issues d'images d'ouvrages d'art démontrent de meilleures performances en temps de calcul et robustesse que les algorithmes existants. En amont de l'étape de détection, il est nécessaire de s’assurer que les images acquises soient de bonne qualité pour réaliser le traitement. Une mauvaise mise au point ou un flou de bougé sont à bannir. Nous avons développé une méthode réutilisant les calculs de la détection en extrayant des mesures de Local Binary Patterns (LBP) afin de vérifier la qualité en temps réel. Enfin, pour réaliser une acquisition permettant une reconstruction photogrammétrique, les images doivent avoir un recouvrement suffisant. Notre algorithme, réutilisant les points d’intérêts de la détection, permet un appariement simple entre deux images sans passer par des algorithmes de type RANSAC. Notre méthode est invariante en rotation, translation et à une certaine plage de changements d’échelle. Après l’acquisition, sur les images de qualité optimale, il est possible d'employer des méthodes plus coûteuses en temps comme les réseaux de neurones à convolution. Ces derniers bien qu'incapables d’assurer une détection de fissures en temps réel peuvent être utilisés pour détecter certains types d’avaries. Cependant, le manque de données impose la constitution de notre propre jeu de données. A l'aide d'approches de classification indépendante (classifieurs SVM one-class), nous avons développé un système flexible capable d’évoluer dans le temps, de détecter puis de classifier les différents types de défauts. Aucun système de ce type n’apparaît dans la littérature. Les travaux réalisés sur l’extraction de caractéristiques sur des images pour la détection de défauts pourront être utiles dans d’autres applications telles que la navigation de véhicules intelligents ou le word-spotting<br>The french railway network has a huge infrastructure which is composed of many civil engineering structures. These suffer from degradation of time and traffic and they are subject to a periodic monitoring in order to detect appearance of defects. At the moment, this inspection is mainly done visually by monitoring operators. Several companies test new vectors of photo acquisition like the drone, designed for civil engineering monitoring. In this thesis, the main goal is to develop a system able to detect, localize and save potential defects of the infrastructure. A huge issue is to detect sub-pixel defects like cracks in real time for improving the acquisition. For this task, a local analysis by thresholding is designed for treating large images. This analysis can extract some points of interest (FLASH points: Fast Local Analysis by threSHolding) where a straight line can sneak in. The smart spatial relationship of these points allows to detect and localise fine cracks. The results of the crack detection on concrete degraded surfaces coming from images of infrastructure show better performances in time and robustness than the state-of-art algorithms. Before the detection step, we have to ensure the acquired images have a sufficient quality to make the process. A bad focus or a movement blur are prohibited. We developed a method reusing the preceding computations to assess the quality in real time by extracting Local Binary Pattern (LBP) values. Then, in order to make an acquisition for photogrammetric reconstruction, images have to get a sufficient overlapping. Our algorithm, reusing points of interest of the detection, can make a simple matching between two images without using algorithms as type RANSAC. Our method has invariance in rotation, translation and scale range. After the acquisition, with images with optimal quality, it is possible to exploit methods more expensive in time like convolution neural networks. These are not able to detect cracks in real time but can detect other kinds of damages. However, the lack of data requires the constitution of our database. With approaches of independent classification (classifier SVM one-class), we developed a dynamic system able to evolve in time, detect and then classify the different kinds of damages. No system like ours appears in the literature for the defect detection on civil engineering structure. The implemented works on feature extraction on images for damage detection will be used in other applications as smart vehicle navigation or word spotting
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Manivannan, Siyamalan. "Visual feature learning with application to medical image classification." Thesis, University of Dundee, 2015. https://discovery.dundee.ac.uk/en/studentTheses/10e26212-e836-4ccd-9b12-a576458de5eb.
Full textAbstract:
Various hand-crafted features have been explored for medical image classification, which include SIFT and Local Binary Patterns (LBP). However, hand-crafted features may not be optimally discriminative for classifying images from particular domains (e.g. colonoscopy), as not necessarily tuned to the domain’s characteristics. In this work, I give emphasis on learning highly discriminative local features and image representations to achieve the best possible classification performance for medical images, particularly for colonoscopy and histology (cell) images. I propose approaches to learn local features using unsupervised and weakly-supervised methods, and an approach to improve the feature encoding methods such as bag-of-words. Unlike the existing work, the proposed weakly-supervised approach uses image-level labels to learn the local features. Requiring image-labels instead of region-level labels makes annotations less expensive, and closer to the data normally available from normal clinical practice, hence more feasible in practice. In this thesis, first, I propose a generalised version of the LBP descriptor called the Generalised Local Ternary Patterns (gLTP), which is inspired by the success of LBP and its variants for colonoscopy image classification. gLTP is robust to both noise and illumination changes, and I demonstrate its competitive performance compared to the best performing LBP-based descriptors on two different datasets (colonoscopy and histology). However LBP-based descriptors (including gLTP) lose information due to the binarisation step involved in their construction. Therefore, I then propose a descriptor called the Extended Multi-Resolution Local Patterns (xMRLP), which is real-valued and reduces information loss. I propose unsupervised and weakly-supervised learning approaches to learn the set of parameters in xMRLP. I show that the learned descriptors give competitive or better performance compared to other descriptors such as root-SIFT and Random Projections. Finally, I propose an approach to improve feature encoding methods. The approach captures inter-cluster features, providing context information in the feature as well as in the image spaces, in addition to the intra-cluster features often captured by conventional feature encoding approaches. The proposed approaches have been evaluated on three datasets, 2-class colonoscopy (2, 100 images), 3-class colonoscopy (2, 800 images) and histology (public dataset, containing 13, 596 images). Some experiments on radiology images (IRMA dataset, public) also were given. I show state-of-the-art or superior classification performance on colonoscopy and histology datasets.
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Cavalcante, Tarique da Silveira. "Método de superfícies ativas usando local binary patterns (LBP) aplicado na segmentação de lobos pulmonares em imagens de tomografia computadorizada do tórax." reponame:Repositório Institucional da UFC, 2016. http://www.repositorio.ufc.br/handle/riufc/19549.
Full textAbstract:
CAVALCANTE, T. S. Método de superfícies ativas usando local binary patterns (LBP) aplicado na segmentação de lobos pulmonares em imagens de tomografia computadorizada do tórax. 2016. 181 f. Tese (Doutorado em Engenharia de Teleinformática) - Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2016.<br>Submitted by Marlene Sousa (mmarlene@ufc.br) on 2016-09-13T17:02:51Z
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Previous issue date: 2016-03-21<br>In several applications involving medical image analysis, the process of image segmentation,
be it automatic or manual, is a present task. An accurate segmentation provides
information for inspection of anatomical structures, to identify diseases and monitoring
of its progress, and even for surgical planning and simulation. Thus, the role of image
segmentation is essential in any medical image analysis system. Among the segmentation
techniques in the literature, the active models technique is one of the most popular approaches
of the last two decades and has been widely used in medical image segmentation,
achieving considerable success. Active models that are applied on three-dimensional applications
are called Active Surfaces Methods (ASM), which has been widely used in the
segmentation of 3D objects, evolving under the influence of their energy to converge to
the desired surface. So, knowing how essential surface extraction is to obtain an accurate
segmentation, this thesis conducts a study on ASM, identifying its advantages and limitations,
and proposes a new ASM to the segmentation of pulmonary lobes on CT images.
The new ASM has as contributions internal forces for unstructured meshes, external energies
based on LBP texture and Hessian matrix, and automatic initialization for each lobe.
In order to validate this proposal, a comparative study of the performance of the internal
forces in synthetic images, along with the comparison of the segmentation of lung lobes
obtained by the proposed method with the segmentation of a gold standard carried out
by an expert medical board will be conducted. The results show that the internal forces
performs well, providing synthetic images segmentation with average distance of less than
1 voxel and adjustment measures of 0.95. The automatic initialization has also achieved
significant results, with overall hit rate of 94%. Finally, the rates obtained for pulmonary
lobe segmentation allows validation of the proposed method with average distance values
of 1.93 mm and rates of size and form adjustment of 0.98 and 0.89, respectively. Thus,
it is concluded that the obtained metric is sufficient to validate the lobar segmentation
obtained in this thesis<br>Em diversas aplica¸c˜oes de an´alise de imagens m´edicas, o processo de segmenta¸c˜ao de
imagens, seja autom´atico ou manual, ´e uma tarefa presente. Uma segmenta¸c˜ao correta
fornece informa¸c˜oes para inspe¸c˜ao de estruturas anatˆomicas, para a identifica¸c˜ao de
doen¸cas e acompanhamento de seu progresso e at´e mesmo para o planejamento cir´urgico
e simula¸c˜ao. Logo, o papel da segmenta¸c˜ao de imagens ´e essencial em qualquer sistema de
an´alise de imagens m´edicas. Dentre as t´ecnicas de segmenta¸c˜ao presentes na literatura, a
t´ecnica de modelos ativos ´e uma das abordagens mais populares durante as duas ´ultimas
d´ecadas e tem sido amplamente utilizada em segmenta¸c˜ao de imagens m´edicas, obtendo
um sucesso consider´avel. Os modelos ativos que atuam em aplica¸c˜oes tridimensionais s˜ao
denominados de M´etodos de Superf´ıcies Ativas (MSA), que por sua vez tˆem sido bastante
utilizados na segmenta¸c˜ao de objetos 3D, evoluindo sob a influˆencia de suas energias at´e
convergir para a superf´ıcie desejada. Neste sentido, tendo em vista que a extra¸c˜ao de
superf´ıcie ´e essencial para a obten¸c˜ao de uma correta segmenta¸c˜ao, a presente tese realiza
um estudo sobre MSA, identificando suas vantagens e limita¸c˜oes, e prop˜oe um novo MSA
para a segmenta¸c˜ao de lobos pulmonares em imagens de TC. Esta novo MSA tem como
contribui¸c˜oes for¸cas internas para malhas n˜ao estruturadas, energias externas baseadas
em textura LBP e matriz Hessiana, al´em de inicializa¸c˜ao autom´atica por lobo pulmonar.
Para validar a proposta ´e realizado um estudo comparativo da atua¸c˜ao das for¸cas internas
em imagens sint´eticas, al´em da compara¸c˜ao da segmenta¸c˜ao dos lobos pulmonares obtida
pelo m´etodo proposto com a segmenta¸c˜ao de um padr˜ao ouro realizado por uma junta
m´edica especialista. Os resultados comprovam que as for¸cas internas apresentam bom
desempenho na segmenta¸c˜ao de imagens sint´eticas com valores de distˆancia m´edia menores
que 1 voxel e com medidas de ajuste maiores do que 0,95. A inicializa¸c˜ao autom´atica
tamb´em obteve resultados relevantes, com taxa de acerto geral igual a 94%. Por fim,
os valores obtidos para a segmenta¸c˜ao dos lobos pulmonares permitem validar o m´etodo
proposto com valores de distˆancia m´edia igual a 1,93 mm e valores de ajuste de tamanho
e de forma de 0,98 e 0,89, respectivamente. Neste contexto, conclui-se que as m´etricas
apresentadas neste trabalho s˜ao suficientes para validar a segmenta¸c˜ao lobar obtida nesta
tese
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Pasáček, Václav. "Segmentace obrazu podle textury." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2012. http://www.nusl.cz/ntk/nusl-236463.
Full textAbstract:
Image segmentation is an important step in image processing. A traditional way how to segment an image is a texture-based segmentation that uses texture features to describe image texture. In this work, Local Binary Patterns (LBP) are used for image texture representation. Texture feature is a histogram of occurences of LBP codes in a small image window. The work also aims to comparison of results of various modifications of Local Binary Patterns and their usability in the image segmentation which is done by unsupervised clustering of texture features. The Fuzzy C-Means algorithm is finally used for the clustering in this work.
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Slavík, Roman. "Detektor obličejů pro platformu Android." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2011. http://www.nusl.cz/ntk/nusl-236977.
Full textAbstract:
This master's thesis deals with face detection on mobile phones with Android OS. The introduction describes some algorithms used for pattern detection from image, as well as various techniques of features extracting. After that Android platform development specifics, including basic description of development tools, are described. Architecture of SIMD is introduced in next part of this work. After acquiring basic knowleage analysis and implementation of final app are descrited. Performance tests are conducted whose results are summarized in the conclusion.
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Wang, Benjamin. "Lip Detection and Adaptive Tracking." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1695.
Full textAbstract:
Performance of automatic speech recognition (ASR) systems utilizing only acoustic information degrades significantly in noisy environments such as a car cabins. Incorporating audio and visual information together can improve performance in these situations. This work proposes a lip detection and tracking algorithm to serve as a visual front end to an audio-visual automatic speech recognition (AVASR) system.
Several color spaces are examined that are effective for segmenting lips from skin pixels. These color components and several features are used to characterize lips and to train cascaded lip detectors. Pre- and post-processing techniques are employed to maximize detector accuracy. The trained lip detector is incorporated into an adaptive mean-shift tracking algorithm for tracking lips in a car cabin environment. The resulting detector achieves 96.8% accuracy, and the tracker is shown to recover and adapt in scenarios where mean-shift alone fails.
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Mushfieldt, Diego. "Robust facial expression recognition in the presence of rotation and partial occlusion." Thesis, University of Western Cape, 2014. http://hdl.handle.net/11394/3367.
Full textAbstract:
>Magister Scientiae - MSc<br>This research proposes an approach to recognizing facial expressions in the presence of
rotations and partial occlusions of the face. The research is in the context of automatic
machine translation of South African Sign Language (SASL) to English. The proposed
method is able to accurately recognize frontal facial images at an average accuracy of
75%. It also achieves a high recognition accuracy of 70% for faces rotated to 60◦. It was
also shown that the method is able to continue to recognize facial expressions even in
the presence of full occlusions of the eyes, mouth and left/right sides of the face. The
accuracy was as high as 70% for occlusion of some areas. An additional finding was that
both the left and the right sides of the face are required for recognition. As an addition,
the foundation was laid for a fully automatic facial expression recognition system that
can accurately segment frontal or rotated faces in a video sequence.
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Hrubý, Michal. "Využití grafického procesoru jako akcelerátoru - technologie OpenCL." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2011. http://www.nusl.cz/ntk/nusl-236932.
Full textAbstract:
This work deals with the OpenCL technology and its use for the task of object detection. The introduction is devoted to description of OpenCL fundamentals, as well as basic theory of object detection. Next chapter of the work is analysis, with design proposal which takes into consideration the possibilities of OpenCL. Further, there's description of implementation of detection application and experimental evaluation of detector's performance. The last chapter summarizes the achieved results.
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Alamgir, Nyma. "Computer vision based smoke and fire detection for outdoor environments." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/201654/1/Nyma_Alamgir_Thesis.pdf.
Full textAbstract:
Surveillance Video-based detection of outdoor smoke and fire has been a challenging task due to the chaotic variations of shapes, movement, colour, texture, and density. This thesis contributes to the advancement of the contemporary efforts of smoke and fire detection by proposing novel technical methods and their possible integration into a complete fire safety model. The novel contributions of this thesis include an efficient feature calculation method combining local and global texture properties, the development of deep learning-based models and a conceptual framework to incorporate weather information in the fire safety model for improved accuracy in fire prediction and detection.
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Marija, Delić. "Modeli neodređenosti u obradi digitalnih slika." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2020. https://www.cris.uns.ac.rs/record.jsf?recordId=114273&source=NDLTD&language=en.
Full textAbstract:
Problemi klasifikacije i segmentacije digitalnih slika su veomaaktuelni i zastupljeni u praksi. Potreba za modelima koji razmatrajuovu problematiku u poslednjih nekoliko decenija ubrzanim tempompoprima sve veći značaj i obim u svakodnevnom životu. Koriste se uračunarskoj grafici, prepoznavanju oblika, medicinskoj analizi slika,saobraćaju, analizi dokumenata, pokreta i izraza lica i sl.U okviru ove disertacije, predstavljeno istraživanje motivisano jeprimenama razvijenih modela u klasifikaciji i segmentacijidigitalnih slika. Istraživanje obuhvata dva segmenta. Ovi segmentipovezani su terminom neodređenosti, koji je uz upotrebu adekvatnogmatematičkog aparata (teorije fazi skupova), ugrađen u modele razvijeza primenu u obradi slike.Jedan pravac istraživanja baziran je na teoriji fazi skupova, t-normama, t-konormama, operatorima agregacije i agregiranimfunkcijama rastojanja. U okviru toga, istraživanje je sprovedeno sastruktuiranom matematičkom podlogom, izložene su osnovnedefinicije, teoreme, kao i osobine korištenih operatora, proširenisu teorijski koncepti t-normi i t-konormi. Definisani su novi tipovioperatora agregacije i njihovom primenom konstruisane su novefunkcije rastojanja, čija je upotreba diskutovana kroz uspešnost uprocesu segmentacije digitalnih slika.Drugi pravac istraživanja, izložen u ovoj disertaciji, obuhvata višeinženjerski pristup rešavanju problema klasifikacije teksturadigitalnih slika. U skladu sa tim, detaljno je analizirana idiskutovana klasa lokalnih binarnih deskriptora teksture.Inspirisana uspešnošću pomenute LBP klase deskriptora, uvedena jejedna nova podfamilija α-deskriptora teksture. Uvedeni modeldeskriptora formiran je na temeljima idejnih principa lokalnihbinarnih kodova i bazičnih pojmova iz teorije fazi skupova. Praktičnaupotreba i značaj predstavljenog modela demonstrirani su kroz veomauspešne procese klasifikacije na nekoliko javno dostupnih baza slika.<br>Classification and segmentation problems of digital images is a very attractivetopic and has been making impact in many different applied disciplines. In thepast few decades, the demand for models that address these issues has beengaining momentum and applications in everyday life. These models are used incomputer graphics, shape recognition, medical image analysis, traffic, documentanalysis, facial movements and expressions, etc.The research within this doctoral dissertation was motivated by the application ofdeveloped methods in classification and segmentation tasks. The conductedresearch covered two segments, which were linked by the term of indeterminacy,with the usage of the theory of fuzzy sets, which is incorporated into methodsdeveloped for application in image processing.One direction of the research was founded on the theory of fuzzy sets, t-norms,t-conorms, aggregation operators, and aggregated distance functions. Within thisframework, the research was conducted with a structured mathematicalbackground. Firstly, basic definitions, theorems and characteristics of the usedoperators were presented, followed by the theoretical concepts of t-norms and tconormsthat were extended. New types of aggregation operators and distancefunctions were defined, and finally, their contribution in the digital imagesegmentation process was explored and discussed.The second direction of the research presented in this dissertation involved moreof an engineering-type of approach to solving the problem of the classification ofdigital image textures. To that end, a class of local binary texture descriptors(LBPs) was analyzed and discussed in detail. Inspired by the results of theabove-mentioned LBP descriptors, one new sub-family of the $\alpha$-descriptors was introduced by the author. The introduced descriptor model wasbased on the conceptual principles of LBPs and basic definitions from the fuzzyset theory. Its practical usage and importance were established and reflected invery successful classification results, achieved in the application on severalpublicly available image datasets.
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Romero, Mier y. Teran Andrés. "Real-time multi-target tracking : a study on color-texture covariance matrices and descriptor/operator switching." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-01002065.
Full textAbstract:
Visual recognition is the problem of learning visual categories from a limited set of samples and identifying new instances of those categories, the problem is often separated into two types: the specific case and the generic category case. In the specific case the objective is to identify instances of a particular object, place or person. Whereas in the generic category case we seek to recognize different instances that belong to the same conceptual class: cars, pedestrians, road signs and mugs. Specific object recognition works by matching and geometric verification. In contrast, generic object categorization often includes a statistical model of their appearance and/or shape.This thesis proposes a computer vision system for detecting and tracking multiple targets in videos. A preliminary work of this thesis consists on the adaptation of color according to lighting variations and relevance of the color. Then, literature shows a wide variety of tracking methods, which have both advantages and limitations, depending on the object to track and the context. Here, a deterministic method is developed to automatically adapt the tracking method to the context through the cooperation of two complementary techniques. A first proposition combines covariance matching for modeling characteristics texture-color information with optical flow (KLT) of a set of points uniformly distributed on the object . A second technique associates covariance and Mean-Shift. In both cases, the cooperation allows a good robustness of the tracking whatever the nature of the target, while reducing the global execution times .The second contribution is the definition of descriptors both discriminative and compact to be included in the target representation. To improve the ability of visual recognition of descriptors two approaches are proposed. The first is an adaptation operators (LBP to Local Binary Patterns ) for inclusion in the covariance matrices . This method is called ELBCM for Enhanced Local Binary Covariance Matrices . The second approach is based on the analysis of different spaces and color invariants to obtain a descriptor which is discriminating and robust to illumination changes.The third contribution addresses the problem of multi-target tracking, the difficulties of which are the matching ambiguities, the occlusions, the merging and division of trajectories.Finally to speed algorithms and provide a usable quick solution in embedded applications this thesis proposes a series of optimizations to accelerate the matching using covariance matrices. Data layout transformations, vectorizing the calculations (using SIMD instructions) and some loop transformations had made possible the real-time execution of the algorithm not only on Intel classic but also on embedded platforms (ARM Cortex A9 and Intel U9300).
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Macenauer, Pavel. "Detekce objektů na GPU." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2015. http://www.nusl.cz/ntk/nusl-234942.
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This thesis addresses the topic of object detection on graphics processing units. As a part of it, a system for object detection using NVIDIA CUDA was designed and implemented, allowing for realtime video object detection and bulk processing. Its contribution is mainly to study the options of NVIDIA CUDA technology and current graphics processing units for object detection acceleration. Also parallel algorithms for object detection are discussed and suggested.
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Hochman, Zdeněk. "Detekce pohybujících se objektů ve video sekvenci." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2010. http://www.nusl.cz/ntk/nusl-237242.
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This thesis deals with moving objects detection in video sequences. The principal aim of such detection is to detect and locate motion in the image, separate individual objects, and track these objects. Subsequently, to eliminate shadows, the paper introduces method of motion detection based on Local Binary Patterns together with differential method above the HSV color space. The proposed method provides rapid and accurate movement detection in video sequences.
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Kula, Michal. "Algoritmy grafiky a video v GP-GPU." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236364.
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This diploma thesis is focused on object detections through general-purpose computing on graphics processor units. There is an explanation of graphics adapters work and basics of their architecture in this thesis. Based on the adapters, there is the effective work in libraries for general-purpose computing on graphics processor units demonstrated in this thesis. Further, the thesis shows the available algorithms for object detection and which ones from them are possible to be effectively parallelized. In conclusion of this thesis, there is a comparison of the object detections speeds to common implementations on classical processors.
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Zahradnik, Roman. "Texturní příznaky." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2007. http://www.nusl.cz/ntk/nusl-236898.
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Aim of this project is to evaluate effectivity of various texture features within the context of image processing, particulary the task of texture recognition and classification. My work focuses on comparing and discussion of usage and efficiency of texture features based on local binary patterns and co- ccurence matrices. As classification algorithm is concerned, cluster analysis was choosen.
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Hutárek, Jiří. "Klasifikace objektů v obraze podle textury." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2010. http://www.nusl.cz/ntk/nusl-237277.
Full textAbstract:
Main subjects of this thesis are texture classification and texture-based object recognition. Various texture features are being explored, including several variants of local binary patterns (LBP). A novel modification of LBP (weighted spatial LBP) is proposed, with intention to improve on the spatial coverage of the traditional LBP. Rarely used color texture features are being discussed as well. Artificial neural networks and support vector machines are used to classify all the aforementioned features. Using these methods, framework for the texture classification and image segmentation is implemented. Comprehensive texture database is employed to test its performance under different conditions. In the end, the system is applied to solve a real-world problem - the segmentation of aerial photos.
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Houam, Lotfi. "Contribution à l'analyse de textures de radiographies osseuses pour le diagnostic précoce de l'ostéoporose." Phd thesis, Université d'Orléans, 2013. http://tel.archives-ouvertes.fr/tel-01022935.
Full textAbstract:
L'ostéoporose est une maladie osseuse caractérisée par une perte importante de la masse osseuse et des altérations de la microarchitecture du tissu osseux. Aujourd'hui, en routine clinique, le diagnostic de l'ostéoporose est basé principalement sur une mesure de la densité minérale osseuse qui n'est pas suffisante, car elle doit être accompagnée par une analyse de la qualité de la microarchitecture osseuse. Les travaux présentés dans cette thèse concernent la caractérisation des images de radiographies osseuses pour le diagnostic précoce de l'ostéoporose. Pour ce faire, afin de mieux caractériser la texture osseuse sur radiographie, nous avons introduit une nouvelle technique de prétraitement des données pour réduire les redondances et éliminer le bruit issu des capteurs d'acquisition. Pour la caractérisation, nous avons proposé une nouvelle technique d'analyse inspirée des motifs binaires locaux (Local Binary Patterns, LBP). Le nouveau descripteur, appelé 1DLBP (One Dimensional Local Binary Patterns) s'applique de manière unidimensionnelle. Pour tester l'efficacité de notre approche, nous avons réalisé deux études cliniques où le nouveau descripteur LBP1D est comparé à la méthode classique, LBP afin de classifier des patients ostéoporotiques et des sujets sains. Les pourcentages de classification obtenus ont été améliorés de 72% avec la méthode classique LBP à 91% avec le nouveau descripteur 1DLBP.
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Korchakov, Sergei. "Zpracování obrazu v systému Android - detekce a rozpoznání obličeje." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220900.
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This master’s Thesis focuses on image processing on Android platform and development of an application, that is able to do face detection and recognition in real scene. Thesis gives highlight of modern algorithms of face detection. It first examines and compares the standard features of Android platform (FaceDetector a FaceDetectionListener) and JJIL, OpenIMAJ, OpenCV libraries experiment, and presents the results. For purposes of face recognition was selected OpenCV library. Three different algorithms of identification were tested: FisherFaces, EigenFaces a Local Binary Patterns Histograms. Based on performance comparison best methods were implemented in developed application.
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Kubínek, Jiří. "Detekce objektů v obraze." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2009. http://www.nusl.cz/ntk/nusl-236646.
Full textAbstract:
This work is dedicated to methods used for object detection in images. There is a summary of several approaches and algorithms to solve this matter, especially AdaBoost algorithm with its improvement, WaldBoost and several features used for object detection. Vital part of this work is dedicated to extending training datasets for classifier training and extending the current object detection framework with histogram of gradients features implementation. Integral part of this work is analysis of results by experiments evaluation.