393 research outputs found

    Highly efficient low-level feature extraction for video representation and retrieval.

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    PhDWitnessing the omnipresence of digital video media, the research community has raised the question of its meaningful use and management. Stored in immense multimedia databases, digital videos need to be retrieved and structured in an intelligent way, relying on the content and the rich semantics involved. Current Content Based Video Indexing and Retrieval systems face the problem of the semantic gap between the simplicity of the available visual features and the richness of user semantics. This work focuses on the issues of efficiency and scalability in video indexing and retrieval to facilitate a video representation model capable of semantic annotation. A highly efficient algorithm for temporal analysis and key-frame extraction is developed. It is based on the prediction information extracted directly from the compressed domain features and the robust scalable analysis in the temporal domain. Furthermore, a hierarchical quantisation of the colour features in the descriptor space is presented. Derived from the extracted set of low-level features, a video representation model that enables semantic annotation and contextual genre classification is designed. Results demonstrate the efficiency and robustness of the temporal analysis algorithm that runs in real time maintaining the high precision and recall of the detection task. Adaptive key-frame extraction and summarisation achieve a good overview of the visual content, while the colour quantisation algorithm efficiently creates hierarchical set of descriptors. Finally, the video representation model, supported by the genre classification algorithm, achieves excellent results in an automatic annotation system by linking the video clips with a limited lexicon of related keywords

    Fuzzy-Rough Intrigued Harmonic Discrepancy Clustering

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    Theory of Colour Harmony and Its Application

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    The colour represents an essential element of visual and graphic communications. It plays an important role in the perception of visual design and it is significant for all participants in the process of planning, developing and promoting graphic products. Designers are interested in a psychological and presentational aspect of colours, while to the technologists the colour represents one of the most important quality attributes. The process of choosing colours that are harmonious, usable and efficient is complex. In addition, many designers have inadequate background knowledge of colour theory, which could help them with the selection of colours. As a result, designers usually spend a great deal of time and expend significant effort in choosing appropriate colour combinations. In this article, the importance of colour harmony and its application when extracting colours, rating and generating colour schemes is presented

    Segmentation of motion picture images and image sequences

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    Analysing Economic Data with Self-Organizing Maps - A Geometric Neural Network Approach

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    Self-Organizing Maps (SOM) are a special form of Neural Networks that use unsupervised learning and auto-classification of data. Therefore, SOM is a very flexible algorithm which is in particular well-suited to identify unexpected structures in complex (and multidimensional) data sets. We use SOM in order to build feature-domain models, i.e. we rather focus on the geometric or symbolic characteristics of patterns within a time series than on their respective location in time. In a next step we try to extract valuable information from the discovered features in order to forecast out-of-sample. We employ the proposed method with different financial time series and test for its performance by means of a set of non-parametric tests. Moreover, the SOM is employed as a clustering algorithm. The method is used in order to form homogenous groups out of 55 countries only by looking at a set of macro data. Without giving any learning guidelines and/or model restrictions the SOM turns out to be a powerful tool for the identification of clusters in the data through its self-organising behaviour

    Multiobjective Image Color Quantization Algorithm Based on Self-Adaptive Hybrid Differential Evolution

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    In recent years, some researchers considered image color quantization as a single-objective problem and applied heuristic algorithms to solve it. This paper establishes a multiobjective image color quantization model with intracluster distance and intercluster separation as its objectives. Inspired by a multipopulation idea, a multiobjective image color quantization algorithm based on self-adaptive hybrid differential evolution (MoDE-CIQ) is then proposed to solve this model. Two numerical experiments on four common test images are conducted to analyze the effectiveness and competitiveness of the multiobjective model and the proposed algorithm
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