1,351 research outputs found

    Learning Local Metrics and Influential Regions for Classification

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    The performance of distance-based classifiers heavily depends on the underlying distance metric, so it is valuable to learn a suitable metric from the data. To address the problem of multimodality, it is desirable to learn local metrics. In this short paper, we define a new intuitive distance with local metrics and influential regions, and subsequently propose a novel local metric learning method for distance-based classification. Our key intuition is to partition the metric space into influential regions and a background region, and then regulate the effectiveness of each local metric to be within the related influential regions. We learn local metrics and influential regions to reduce the empirical hinge loss, and regularize the parameters on the basis of a resultant learning bound. Encouraging experimental results are obtained from various public and popular data sets

    Fast Landmark Localization with 3D Component Reconstruction and CNN for Cross-Pose Recognition

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    Two approaches are proposed for cross-pose face recognition, one is based on the 3D reconstruction of facial components and the other is based on the deep Convolutional Neural Network (CNN). Unlike most 3D approaches that consider holistic faces, the proposed approach considers 3D facial components. It segments a 2D gallery face into components, reconstructs the 3D surface for each component, and recognizes a probe face by component features. The segmentation is based on the landmarks located by a hierarchical algorithm that combines the Faster R-CNN for face detection and the Reduced Tree Structured Model for landmark localization. The core part of the CNN-based approach is a revised VGG network. We study the performances with different settings on the training set, including the synthesized data from 3D reconstruction, the real-life data from an in-the-wild database, and both types of data combined. We investigate the performances of the network when it is employed as a classifier or designed as a feature extractor. The two recognition approaches and the fast landmark localization are evaluated in extensive experiments, and compared to stateof-the-art methods to demonstrate their efficacy.Comment: 14 pages, 12 figures, 4 table

    Open Source Software for Automatic Detection of Cone Photoreceptors in Adaptive Optics Ophthalmoscopy Using Convolutional Neural Networks

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    Imaging with an adaptive optics scanning light ophthalmoscope (AOSLO) enables direct visualization of the cone photoreceptor mosaic in the living human retina. Quantitative analysis of AOSLO images typically requires manual grading, which is time consuming, and subjective; thus, automated algorithms are highly desirable. Previously developed automated methods are often reliant on ad hoc rules that may not be transferable between different imaging modalities or retinal locations. In this work, we present a convolutional neural network (CNN) based method for cone detection that learns features of interest directly from training data. This cone-identifying algorithm was trained and validated on separate data sets of confocal and split detector AOSLO images with results showing performance that closely mimics the gold standard manual process. Further, without any need for algorithmic modifications for a specific AOSLO imaging system, our fully-automated multi-modality CNN-based cone detection method resulted in comparable results to previous automatic cone segmentation methods which utilized ad hoc rules for different applications. We have made free open-source software for the proposed method and the corresponding training and testing datasets available online

    The nature of information in the 21st century : conundrums for the informatics community?

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    Purpose - With the proliferation of electronic information via the web a further distension of the unique characteristics of information has been witnessed. With seismic developments occurring in such a short period of time, it seems prudent to consider the very nature of information and to assess whether this accelerated growth has implications for the work of the informatics community and the information society. Design/methodology/approach - The paper begins by revisiting and refreshing the unique characteristics of information via a reappraisal of the relevant literature. These characteristics are then contextualised within the new economy and traditional economic theory. Once these unique characteristics have been examined, the author discusses how the nature of information in the twenty-first century presents the informatics community with new and difficult challenges. Findings - The challenges posed by the unique nature of information demand a definite response on the part of the informatics community, including the creation of innovative new models to accommodate information's inherent characteristics. Additionally, as the nature of information evolves yet further and ICT innovations accelerate, ever more adaptable skills will be required by the end user in order that value be derived from information. Practical implications - Outcomes and conclusions addressed in the paper may inform the informatics community generally, but will specifically inform the practice of information managers and librarians, and offer ways of assisting them in arriving at holistic decisions with respect to service provision. Originality/value - The paper is a contribution to the debate on the precise nature of information and offers new perspectives on how the informatics community should view information in the twenty-first century

    CVABS: Moving Object Segmentation with Common Vector Approach for Videos

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    Background modelling is a fundamental step for several real-time computer vision applications that requires security systems and monitoring. An accurate background model helps detecting activity of moving objects in the video. In this work, we have developed a new subspace based background modelling algorithm using the concept of Common Vector Approach with Gram-Schmidt orthogonalization. Once the background model that involves the common characteristic of different views corresponding to the same scene is acquired, a smart foreground detection and background updating procedure is applied based on dynamic control parameters. A variety of experiments is conducted on different problem types related to dynamic backgrounds. Several types of metrics are utilized as objective measures and the obtained visual results are judged subjectively. It was observed that the proposed method stands successfully for all problem types reported on CDNet2014 dataset by updating the background frames with a self-learning feedback mechanism.Comment: 12 Pages, 4 Figures, 1 Tabl
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