11,153 research outputs found

    EXTRAÇÃO DE FEIÇÕES EM DADOS DE IMAGENS HIPERESPECTRAIS POR OTIMIZAÇÃO DA DISTÂNCIA DE BHATTACHARYYA EM UM CLASSIFICADOR ÁRVORE DE DECISÃO

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    In this paper we investigate a method for the classification of high-dimensional image data using a multi-stage classifier structured as a binary tree, and employing a reduced number of features at each node, in order to mitigate the Hughesphenomenon. The selected method for feature reduction is based on the optimization of Bhattacharyya distance at each individual node of the tree. As the Bhattacharyya distance is defined for a pair of classes, the binary tree approach allows the extraction of an optimal sub-set of features at each individual node. Experiments were performed using an AVIRIS image data set, varying the number of training samples and also the number of selected features at each node. The results have shown an improvement in the accuracy of the thematic image, as compared to more traditional methods for feature selection and extraction.Neste estudo é investigado um método para fins de classificação de dados imagem em alta dimensionalidade, por meio de um classificador em estágio múltiplo. Esse classificador, estruturado na forma de árvore binária, emprega um número reduzidode feições em cada nó visando reduzir os efeitos do fenômeno de Hughes. O método para redução de feições consiste na otimização da distância de Bhattacharyya em cada nó individual da árvore. O classificador hierárquico estruturado em árvore binária oferece as condições adequadas para implementação deste método, pois a distância de Bhattacharyya está definida para um par declasses, permitindo desta forma a extração de um subconjunto ótimo de feições em cada nó individual. Foram desenvolvidos experimentos empregando dados da imagem AVIRIS, envolvendo diferentes números de amostras de treinamento e de feições extraídas. Os resultados mostraram que sob certas condições a metodologia investigada apresenta resultados mais acurados do que aquelas mais comumente utilizadas para fins de redução na dimensionalidade dos dados

    VSCAN: An Enhanced Video Summarization using Density-based Spatial Clustering

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    In this paper, we present VSCAN, a novel approach for generating static video summaries. This approach is based on a modified DBSCAN clustering algorithm to summarize the video content utilizing both color and texture features of the video frames. The paper also introduces an enhanced evaluation method that depends on color and texture features. Video Summaries generated by VSCAN are compared with summaries generated by other approaches found in the literature and those created by users. Experimental results indicate that the video summaries generated by VSCAN have a higher quality than those generated by other approaches.Comment: arXiv admin note: substantial text overlap with arXiv:1401.3590 by other authors without attributio

    An Automatic Similarity Detection Engine Between Sacred Texts Using Text Mining and Similarity Measures

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    Is there any similarity between the contexts of the Holy Bible and the Holy Quran, and can this be proven mathematically? The purpose of this research is using the Bible and the Quran as our corpus, we explore the performance of various feature extraction and machine learning techniques. The unstructured nature of text data adds an extra layer of complexity in the feature extraction task, and the inherently sparse nature of the corresponding data matrices makes text mining a distinctly difficult task. Among other things, We assess the difference between domain-based syntactic feature extraction and domain-free feature extraction, and then use a variety of similarity measures like Euclidean, Hillinger, Manhattan, cosine, Bhattacharyya, symmetries kullback-leibler, Jensen Shannon, probabilistic chi-square and clark. For a similarity to identify similarities and differences between sacred texts. Initially I started by comparing chapters of two raw text using the proximity measures to visualize their behaviors on high dimensional and spars space. It was apparent there was similarity between some of the chapters, but it was not conclusive. Therefore, there was a need to clean the noise using the so called Natural Language processing (NLP). For example, to minimize the size of two vectors, We initiated lists of similar vocabulary that worded differently in both texts but indicates the same exact meaning. Therefore, the program would recognize Lord as God in the Holy Bible and Allah as God in the Quran and Jacob as prophet in bible and Yaqub as a prophet in Quran. This process was completed many times to give relative comparisons on a variety of different words. After completion of the comparison of the raw texts, the comparison was completed for the processed text. The next comparison was completed using probabilistic topic modeling on feature extracted matrix to project the topical matrix into low dimensional space for more dense comparison. Among the distance measures intrdued to the sacred corpora, the analysis of similarities based on the probability based measures like Kullback leibler and Jenson shown the best result. Another similarity result based on Hellinger distance on the CTM also shows good discrimination result between documents. This work started with a believe that if there is intersection between Bible and Quran, it will be shown clearly between the book of Deuteronomy and some Quranic chapters. It is now not only historically, but also mathematically is correct to say that there is much similarity between the Biblical and Quranic contexts more than the similarity within the holy books themselves. Furthermore, it is the conclusion that distances based on probabilistic measures such as Jeffersyn divergence and Hellinger distance are the recommended methods for the unstructured sacred texts

    An Innovative Skin Detection Approach Using Color Based Image Retrieval Technique

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    From The late 90th, "Skin Detection" becomes one of the major problems in image processing. If "Skin Detection" will be done in high accuracy, it can be used in many cases as face recognition, Human Tracking and etc. Until now so many methods were presented for solving this problem. In most of these methods, color space was used to extract feature vector for classifying pixels, but the most of them have not good accuracy in detecting types of skin. The proposed approach in this paper is based on "Color based image retrieval" (CBIR) technique. In this method, first by means of CBIR method and image tiling and considering the relation between pixel and its neighbors, a feature vector would be defined and then with using a training step, detecting the skin in the test stage. The result shows that the presenting approach, in addition to its high accuracy in detecting type of skin, has no sensitivity to illumination intensity and moving face orientation.Comment: 9 Pages, 4 Figure

    Review of Person Re-identification Techniques

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    Person re-identification across different surveillance cameras with disjoint fields of view has become one of the most interesting and challenging subjects in the area of intelligent video surveillance. Although several methods have been developed and proposed, certain limitations and unresolved issues remain. In all of the existing re-identification approaches, feature vectors are extracted from segmented still images or video frames. Different similarity or dissimilarity measures have been applied to these vectors. Some methods have used simple constant metrics, whereas others have utilised models to obtain optimised metrics. Some have created models based on local colour or texture information, and others have built models based on the gait of people. In general, the main objective of all these approaches is to achieve a higher-accuracy rate and lowercomputational costs. This study summarises several developments in recent literature and discusses the various available methods used in person re-identification. Specifically, their advantages and disadvantages are mentioned and compared.Comment: Published 201
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